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Table des matières
Version : 2022.01
Dernière mise-à-jour : 2022/10/04 15:19
Topic 5: Advanced Storage Device Administration
Contenu du Module
- LCF504 - Gestion des Disques, des Systèmes de Fichiers et du Swap
- Contenu du Module
- Logical Volume Manager (LVM)
- LAB #1 - Volumes Logiques Linéaires
- Physical Volume (PV)
- Volume Group (VG) et Physical Extent (PE)
- Logical Volumes (LV)
- LAB #2 - Étendre un Volume Logique à Chaud
- LAB #3 - Snapshots
- LAB #4 - Suppression des Volumes
- LAB #5 - Volumes Logiques en Miroir
- LAB #6 - Modifier les Attributs LVM
- LAB #7 - Volumes Logiques en Bandes
- LAB #8 - Gérer les Métadonnées
- Raid Logiciel
- LAB #9 - Mise en Place du RAID 5 Logiciel
- Concepts RAID
- Créer une Unité RAID
- Remplacer une Unité Défaillante
Logical Volume Manager (LVM)
LAB #3 - Volumes Logiques Linéaires
Afin de mettre en place le LVM, vous avez besoin du paquet lvm2 et du paquet device-mapper.
Nous allons travailler sous RHEL/CentOS 8 avec les partitions suivantes :
/dev/sdb6 1644544 2054143 409600 200M 8e Linux LVM /dev/sdb7 2056192 2670591 614400 300M 8e Linux LVM /dev/sdb9 3698688 4517887 819200 400M 8e Linux LVM
Pour initialiser le LVM saississez la commande suivante :
[root@centos8 ~]# vgscan Found volume group "cl_centos8" using metadata type lvm2
Les options de la commande vgscan sont :
[root@centos8 ~]# vgscan --longhelp
vgscan - Search for all volume groups
vgscan
[ --ignorelockingfailure ]
[ --mknodes ]
[ --notifydbus ]
[ --reportformat basic|json ]
[ COMMON_OPTIONS ]
Common options for lvm:
[ -d|--debug ]
[ -h|--help ]
[ -q|--quiet ]
[ -v|--verbose ]
[ -y|--yes ]
[ -t|--test ]
[ --commandprofile String ]
[ --config String ]
[ --driverloaded y|n ]
[ --nolocking ]
[ --lockopt String ]
[ --longhelp ]
[ --profile String ]
[ --version ]
Common variables for lvm:
Variables in option or position args are capitalized,
e.g. PV, VG, LV, Size, Number, String, Tag.
PV
Physical Volume name, a device path under /dev.
For commands managing physical extents, a PV positional arg
generally accepts a suffix indicating a range (or multiple ranges)
of PEs. When the first PE is omitted, it defaults to the start of
the device, and when the last PE is omitted it defaults to the end.
PV[:PE-PE]... is start and end range (inclusive),
PV[:PE+PE]... is start and length range (counting from 0).
LV
Logical Volume name. See lvm(8) for valid names. An LV positional
arg generally includes the VG name and LV name, e.g. VG/LV.
LV followed by _<type> indicates that an LV of the given type is
required. (raid represents raid<N> type).
The _new suffix indicates that the LV name is new.
Tag
Tag name. See lvm(8) for information about tag names and using
tags in place of a VG, LV or PV.
Select
Select indicates that a required positional arg can be omitted
if the --select option is used. No arg appears in this position.
Size[UNIT]
Size is an input number that accepts an optional unit.
Input units are always treated as base two values, regardless of
capitalization, e.g. 'k' and 'K' both refer to 1024.
The default input unit is specified by letter, followed by |UNIT.
UNIT represents other possible input units: BbBsSkKmMgGtTpPeE.
(This should not be confused with the output control --units, where
capital letters mean multiple of 1000.)
Physical Volume (PV)
Pour créer le PV il convient d'utiliser la commande pvcreate :
[root@centos8 ~]# pvcreate /dev/sdb6 /dev/sdb7 /dev/sdb9 Physical volume "/dev/sdb6" successfully created. Physical volume "/dev/sdb7" successfully created. Physical volume "/dev/sdb9" successfully created.
Les options de la commande pvcreate sont :
[root@centos8 ~]# pvcreate --longhelp
pvcreate - Initialize physical volume(s) for use by LVM
pvcreate PV ...
[ -f|--force ]
[ -M|--metadatatype lvm2 ]
[ -u|--uuid String ]
[ -Z|--zero y|n ]
[ --dataalignment Size[k|UNIT] ]
[ --dataalignmentoffset Size[k|UNIT] ]
[ --bootloaderareasize Size[m|UNIT] ]
[ --labelsector Number ]
[ --pvmetadatacopies 0|1|2 ]
[ --metadatasize Size[m|UNIT] ]
[ --metadataignore y|n ]
[ --norestorefile ]
[ --setphysicalvolumesize Size[m|UNIT] ]
[ --reportformat basic|json ]
[ --restorefile String ]
[ COMMON_OPTIONS ]
Common options for lvm:
[ -d|--debug ]
[ -h|--help ]
[ -q|--quiet ]
[ -v|--verbose ]
[ -y|--yes ]
[ -t|--test ]
[ --commandprofile String ]
[ --config String ]
[ --driverloaded y|n ]
[ --nolocking ]
[ --lockopt String ]
[ --longhelp ]
[ --profile String ]
[ --version ]
Common variables for lvm:
Variables in option or position args are capitalized,
e.g. PV, VG, LV, Size, Number, String, Tag.
PV
Physical Volume name, a device path under /dev.
For commands managing physical extents, a PV positional arg
generally accepts a suffix indicating a range (or multiple ranges)
of PEs. When the first PE is omitted, it defaults to the start of
the device, and when the last PE is omitted it defaults to the end.
PV[:PE-PE]... is start and end range (inclusive),
PV[:PE+PE]... is start and length range (counting from 0).
LV
Logical Volume name. See lvm(8) for valid names. An LV positional
arg generally includes the VG name and LV name, e.g. VG/LV.
LV followed by _<type> indicates that an LV of the given type is
required. (raid represents raid<N> type).
The _new suffix indicates that the LV name is new.
Tag
Tag name. See lvm(8) for information about tag names and using
tags in place of a VG, LV or PV.
Select
Select indicates that a required positional arg can be omitted
if the --select option is used. No arg appears in this position.
Size[UNIT]
Size is an input number that accepts an optional unit.
Input units are always treated as base two values, regardless of
capitalization, e.g. 'k' and 'K' both refer to 1024.
The default input unit is specified by letter, followed by |UNIT.
UNIT represents other possible input units: BbBsSkKmMgGtTpPeE.
(This should not be confused with the output control --units, where
capital letters mean multiple of 1000.)
Pour visualiser le PV il convient d'utiliser la commande pvdisplay :
[root@centos8 ~]# pvdisplay /dev/sdb6 /dev/sdb7 /dev/sdb9 "/dev/sdb6" is a new physical volume of "200.00 MiB" --- NEW Physical volume --- PV Name /dev/sdb6 VG Name PV Size 200.00 MiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID xsAjLA-sUEU-dexm-H7G1-Dsi4-q6qW-8Tqkay "/dev/sdb7" is a new physical volume of "300.00 MiB" --- NEW Physical volume --- PV Name /dev/sdb7 VG Name PV Size 300.00 MiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID WpssK3-sThn-3nS0-80O3-NcW3-23e0-gxejn4 "/dev/sdb9" is a new physical volume of "400.00 MiB" --- NEW Physical volume --- PV Name /dev/sdb9 VG Name PV Size 400.00 MiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID rqaB99-3UdD-pJxE-Z1Eo-h9yv-tZ41-r4UJSY
Les options de la commande pvdisplay sont :
[root@centos8 ~]# pvdisplay --longhelp
pvdisplay - Display various attributes of physical volume(s)
pvdisplay
[ -a|--all ]
[ -c|--colon ]
[ -C|--columns ]
[ -m|--maps ]
[ -o|--options String ]
[ -S|--select String ]
[ -s|--short ]
[ -O|--sort String ]
[ --aligned ]
[ --binary ]
[ --configreport log|vg|lv|pv|pvseg|seg ]
[ --foreign ]
[ --ignorelockingfailure ]
[ --logonly ]
[ --noheadings ]
[ --nosuffix ]
[ --readonly ]
[ --reportformat basic|json ]
[ --separator String ]
[ --shared ]
[ --unbuffered ]
[ --units r|R|h|H|b|B|s|S|k|K|m|M|g|G|t|T|p|P|e|E ]
[ COMMON_OPTIONS ]
[ PV|Tag ... ]
Common options for lvm:
[ -d|--debug ]
[ -h|--help ]
[ -q|--quiet ]
[ -v|--verbose ]
[ -y|--yes ]
[ -t|--test ]
[ --commandprofile String ]
[ --config String ]
[ --driverloaded y|n ]
[ --nolocking ]
[ --lockopt String ]
[ --longhelp ]
[ --profile String ]
[ --version ]
Common variables for lvm:
Variables in option or position args are capitalized,
e.g. PV, VG, LV, Size, Number, String, Tag.
PV
Physical Volume name, a device path under /dev.
For commands managing physical extents, a PV positional arg
generally accepts a suffix indicating a range (or multiple ranges)
of PEs. When the first PE is omitted, it defaults to the start of
the device, and when the last PE is omitted it defaults to the end.
PV[:PE-PE]... is start and end range (inclusive),
PV[:PE+PE]... is start and length range (counting from 0).
LV
Logical Volume name. See lvm(8) for valid names. An LV positional
arg generally includes the VG name and LV name, e.g. VG/LV.
LV followed by _<type> indicates that an LV of the given type is
required. (raid represents raid<N> type).
The _new suffix indicates that the LV name is new.
Tag
Tag name. See lvm(8) for information about tag names and using
tags in place of a VG, LV or PV.
Select
Select indicates that a required positional arg can be omitted
if the --select option is used. No arg appears in this position.
Size[UNIT]
Size is an input number that accepts an optional unit.
Input units are always treated as base two values, regardless of
capitalization, e.g. 'k' and 'K' both refer to 1024.
The default input unit is specified by letter, followed by |UNIT.
UNIT represents other possible input units: BbBsSkKmMgGtTpPeE.
(This should not be confused with the output control --units, where
capital letters mean multiple of 1000.)
Volume Group (VG) et Physical Extent (PE)
Pour créer un Volume Group dénommé vg0, il convient d'utiliser la commande vgcreate :
[root@centos8 ~]# vgcreate -s 8M vg0 /dev/sdb6 /dev/sdb7 /dev/sdb9 Volume group "vg0" successfully created
Les options de la commande vgcreate sont :
[root@centos8 ~]# vgcreate --help vgcreate - Create a volume group vgcreate VG_new PV ... [ -A|--autobackup y|n ] [ -c|--clustered y|n ] [ -l|--maxlogicalvolumes Number ] [ -p|--maxphysicalvolumes Number ] [ -M|--metadatatype lvm2 ] [ -s|--physicalextentsize Size[m|UNIT] ] [ -f|--force ] [ -Z|--zero y|n ] [ --addtag Tag ] [ --alloc contiguous|cling|cling_by_tags|normal|anywhere|inherit ] [ --metadataprofile String ] [ --labelsector Number ] [ --metadatasize Size[m|UNIT] ] [ --pvmetadatacopies 0|1|2 ] [ --vgmetadatacopies all|unmanaged|Number ] [ --reportformat basic|json ] [ --dataalignment Size[k|UNIT] ] [ --dataalignmentoffset Size[k|UNIT] ] [ --shared ] [ --systemid String ] [ --locktype sanlock|dlm|none ] [ COMMON_OPTIONS ] Common options for lvm: [ -d|--debug ] [ -h|--help ] [ -q|--quiet ] [ -v|--verbose ] [ -y|--yes ] [ -t|--test ] [ --commandprofile String ] [ --config String ] [ --driverloaded y|n ] [ --nolocking ] [ --lockopt String ] [ --longhelp ] [ --profile String ] [ --version ] Use --longhelp to show all options and advanced commands.
Pour afficher les informations concernant vg0, il convient d'utiliser la commande vgdisplay :
[root@centos8 ~]# vgdisplay vg0 --- Volume group --- VG Name vg0 System ID Format lvm2 Metadata Areas 3 Metadata Sequence No 1 VG Access read/write VG Status resizable MAX LV 0 Cur LV 0 Open LV 0 Max PV 0 Cur PV 3 Act PV 3 VG Size 880.00 MiB PE Size 8.00 MiB Total PE 110 Alloc PE / Size 0 / 0 Free PE / Size 110 / 880.00 MiB VG UUID 6cO8IX-xhvn-5J4z-Em2t-7RAq-u3y8-1cVZln
Les options de la commande vgdisplay sont :
[root@centos8 ~]# vgdisplay --help vgdisplay - Display volume group information vgdisplay [ -A|--activevolumegroups ] [ -c|--colon ] [ -C|--columns ] [ -o|--options String ] [ -S|--select String ] [ -s|--short ] [ -O|--sort String ] [ --aligned ] [ --binary ] [ --configreport log|vg|lv|pv|pvseg|seg ] [ --foreign ] [ --ignorelockingfailure ] [ --logonly ] [ --noheadings ] [ --nosuffix ] [ --readonly ] [ --reportformat basic|json ] [ --shared ] [ --separator String ] [ --unbuffered ] [ --units r|R|h|H|b|B|s|S|k|K|m|M|g|G|t|T|p|P|e|E ] [ COMMON_OPTIONS ] [ VG|Tag ... ] Common options for lvm: [ -d|--debug ] [ -h|--help ] [ -q|--quiet ] [ -v|--verbose ] [ -y|--yes ] [ -t|--test ] [ --commandprofile String ] [ --config String ] [ --driverloaded y|n ] [ --nolocking ] [ --lockopt String ] [ --longhelp ] [ --profile String ] [ --version ] Use --longhelp to show all options and advanced commands.
Logical Volumes (LV)
Pour créer un Logical Volume dénommé lv0 dans le Volume Group vg0, il convient d'utiliser la commande lvcreate :
[root@centos8 ~]# lvcreate -L 350 -n lv0 vg0 Rounding up size to full physical extent 352.00 MiB Logical volume "lv0" created.
Important -Notez que la taille du LV est un multiple du PE.
Les options de la commande lvcreate sont :
[root@centos8 ~]# lvcreate --help lvcreate - Create a logical volume Create a linear LV. lvcreate -L|--size Size[m|UNIT] VG [ -l|--extents Number[PERCENT] ] [ --type linear ] [ COMMON_OPTIONS ] [ PV ... ] Create a striped LV (infers --type striped). lvcreate -i|--stripes Number -L|--size Size[m|UNIT] VG [ -l|--extents Number[PERCENT] ] [ -I|--stripesize Size[k|UNIT] ] [ COMMON_OPTIONS ] [ PV ... ] Create a raid1 or mirror LV (infers --type raid1|mirror). lvcreate -m|--mirrors Number -L|--size Size[m|UNIT] VG [ -l|--extents Number[PERCENT] ] [ -R|--regionsize Size[m|UNIT] ] [ --mirrorlog core|disk ] [ --minrecoveryrate Size[k|UNIT] ] [ --maxrecoveryrate Size[k|UNIT] ] [ COMMON_OPTIONS ] [ PV ... ] Create a raid LV (a specific raid level must be used, e.g. raid1). lvcreate --type raid -L|--size Size[m|UNIT] VG [ -l|--extents Number[PERCENT] ] [ -m|--mirrors Number ] [ -i|--stripes Number ] [ -I|--stripesize Size[k|UNIT] ] [ -R|--regionsize Size[m|UNIT] ] [ --minrecoveryrate Size[k|UNIT] ] [ --maxrecoveryrate Size[k|UNIT] ] [ --raidintegrity y|n ] [ --raidintegritymode String ] [ --raidintegrityblocksize Number ] [ COMMON_OPTIONS ] [ PV ... ] Create a raid10 LV. lvcreate -m|--mirrors Number -i|--stripes Number -L|--size Size[m|UNIT] VG [ -l|--extents Number[PERCENT] ] [ -I|--stripesize Size[k|UNIT] ] [ -R|--regionsize Size[m|UNIT] ] [ --minrecoveryrate Size[k|UNIT] ] [ --maxrecoveryrate Size[k|UNIT] ] [ COMMON_OPTIONS ] [ PV ... ] Create a COW snapshot LV of an origin LV. lvcreate -s|--snapshot -L|--size Size[m|UNIT] LV [ -l|--extents Number[PERCENT] ] [ -i|--stripes Number ] [ -I|--stripesize Size[k|UNIT] ] [ -c|--chunksize Size[k|UNIT] ] [ --type snapshot ] [ COMMON_OPTIONS ] [ PV ... ] Create a thin pool. lvcreate --type thin-pool -L|--size Size[m|UNIT] VG [ -l|--extents Number[PERCENT] ] [ -c|--chunksize Size[k|UNIT] ] [ -i|--stripes Number ] [ -I|--stripesize Size[k|UNIT] ] [ --thinpool LV_new ] [ --poolmetadatasize Size[m|UNIT] ] [ --poolmetadataspare y|n ] [ --discards passdown|nopassdown|ignore ] [ --errorwhenfull y|n ] [ COMMON_OPTIONS ] [ PV ... ] Create a cache pool. lvcreate --type cache-pool -L|--size Size[m|UNIT] VG [ -l|--extents Number[PERCENT] ] [ -H|--cache ] [ -c|--chunksize Size[k|UNIT] ] [ --poolmetadatasize Size[m|UNIT] ] [ --poolmetadataspare y|n ] [ --cachemode writethrough|writeback|passthrough ] [ --cachepolicy String ] [ --cachesettings String ] [ --cachemetadataformat auto|1|2 ] [ COMMON_OPTIONS ] [ PV ... ] Create a thin LV in a thin pool (infers --type thin). lvcreate -V|--virtualsize Size[m|UNIT] --thinpool LV_thinpool VG [ -T|--thin ] [ --type thin ] [ --discards passdown|nopassdown|ignore ] [ --errorwhenfull y|n ] [ COMMON_OPTIONS ] Create a thin LV that is a snapshot of an existing thin LV (infers --type thin). lvcreate -s|--snapshot LV_thin [ --type thin ] [ --discards passdown|nopassdown|ignore ] [ --errorwhenfull y|n ] [ COMMON_OPTIONS ] Create a thin LV that is a snapshot of an external origin LV. lvcreate --type thin --thinpool LV_thinpool LV [ -T|--thin ] [ -c|--chunksize Size[k|UNIT] ] [ --poolmetadatasize Size[m|UNIT] ] [ --poolmetadataspare y|n ] [ --discards passdown|nopassdown|ignore ] [ --errorwhenfull y|n ] [ COMMON_OPTIONS ] Create a LV that returns VDO when used. lvcreate --type vdo -L|--size Size[m|UNIT] VG [ -l|--extents Number[PERCENT] ] [ -V|--virtualsize Size[m|UNIT] ] [ -i|--stripes Number ] [ -I|--stripesize Size[k|UNIT] ] [ --vdo ] [ --vdopool LV_new ] [ --compression y|n ] [ --deduplication y|n ] [ COMMON_OPTIONS ] [ PV ... ] Create a thin LV, first creating a thin pool for it, where the new thin pool is named by the --thinpool arg. lvcreate --type thin -V|--virtualsize Size[m|UNIT] -L|--size Size[m|UNIT] --thinpool LV_new [ -l|--extents Number[PERCENT] ] [ -T|--thin ] [ -c|--chunksize Size[k|UNIT] ] [ -i|--stripes Number ] [ -I|--stripesize Size[k|UNIT] ] [ --poolmetadatasize Size[m|UNIT] ] [ --poolmetadataspare y|n ] [ --discards passdown|nopassdown|ignore ] [ --errorwhenfull y|n ] [ COMMON_OPTIONS ] [ PV ... ] Create a new LV, then attach the specified cachepool which converts the new LV to type cache. lvcreate --type cache -L|--size Size[m|UNIT] --cachepool LV_cachepool VG [ -l|--extents Number[PERCENT] ] [ -H|--cache ] [ -c|--chunksize Size[k|UNIT] ] [ -i|--stripes Number ] [ -I|--stripesize Size[k|UNIT] ] [ --poolmetadatasize Size[m|UNIT] ] [ --poolmetadataspare y|n ] [ --cachemode writethrough|writeback|passthrough ] [ --cachepolicy String ] [ --cachesettings String ] [ --cachemetadataformat auto|1|2 ] [ COMMON_OPTIONS ] [ PV ... ] Create a new LV, then attach the specified cachevol which converts the new LV to type cache. lvcreate --type cache -L|--size Size[m|UNIT] --cachevol LV VG [ -l|--extents Number[PERCENT] ] [ -c|--chunksize Size[k|UNIT] ] [ -i|--stripes Number ] [ -I|--stripesize Size[k|UNIT] ] [ --cachemode writethrough|writeback|passthrough ] [ --cachepolicy String ] [ --cachesettings String ] [ --cachemetadataformat auto|1|2 ] [ COMMON_OPTIONS ] [ PV ... ] Create a new LV, then attach a cachevol created from the specified cache device, which converts the new LV to type cache. lvcreate --type cache -L|--size Size[m|UNIT] --cachedevice PV VG [ -l|--extents Number[PERCENT] ] [ -c|--chunksize Size[k|UNIT] ] [ -i|--stripes Number ] [ -I|--stripesize Size[k|UNIT] ] [ --cachemode writethrough|writeback|passthrough ] [ --cachepolicy String ] [ --cachesettings String ] [ --cachemetadataformat auto|1|2 ] [ --cachesize Size[m|UNIT] ] [ COMMON_OPTIONS ] [ PV ... ] Create a new LV, then attach the specified cachevol which converts the new LV to type writecache. lvcreate --type writecache -L|--size Size[m|UNIT] --cachevol LV VG [ -l|--extents Number[PERCENT] ] [ -i|--stripes Number ] [ -I|--stripesize Size[k|UNIT] ] [ --cachesettings String ] [ COMMON_OPTIONS ] [ PV ... ] Create a new LV, then attach a cachevol created from the specified cache device, which converts the new LV to type writecache. lvcreate --type writecache -L|--size Size[m|UNIT] --cachedevice PV VG [ -l|--extents Number[PERCENT] ] [ -i|--stripes Number ] [ -I|--stripesize Size[k|UNIT] ] [ --cachesize Size[m|UNIT] ] [ --cachesettings String ] [ COMMON_OPTIONS ] [ PV ... ] Common options for command: [ -a|--activate y|n|ay ] [ -A|--autobackup y|n ] [ -C|--contiguous y|n ] [ -M|--persistent y|n ] [ -j|--major Number ] [ -k|--setactivationskip y|n ] [ -K|--ignoreactivationskip ] [ -n|--name String ] [ -p|--permission rw|r ] [ -r|--readahead auto|none|Number ] [ -W|--wipesignatures y|n ] [ -Z|--zero y|n ] [ --addtag Tag ] [ --alloc contiguous|cling|cling_by_tags|normal|anywhere|inherit ] [ --ignoremonitoring ] [ --metadataprofile String ] [ --minor Number ] [ --monitor y|n ] [ --nosync ] [ --noudevsync ] [ --reportformat basic|json ] Common options for lvm: [ -d|--debug ] [ -h|--help ] [ -q|--quiet ] [ -v|--verbose ] [ -y|--yes ] [ -t|--test ] [ --commandprofile String ] [ --config String ] [ --driverloaded y|n ] [ --nolocking ] [ --lockopt String ] [ --longhelp ] [ --profile String ] [ --version ] Use --longhelp to show all options and advanced commands.
Créez maintenant un répertoire dans /mnt pour monter lv0 :
[root@centos8 ~]# mkdir /mnt/lvm
Créez un système de fichiers en ext3 sur /dev/vg0/lv0 :
[root@centos8 ~]# mke2fs -j /dev/vg0/lv0 mke2fs 1.45.6 (20-Mar-2020) Creating filesystem with 360448 1k blocks and 90112 inodes Filesystem UUID: 87b6d526-d379-4e0c-8984-94811f1cee33 Superblock backups stored on blocks: 8193, 24577, 40961, 57345, 73729, 204801, 221185 Allocating group tables: done Writing inode tables: done Creating journal (8192 blocks): done Writing superblocks and filesystem accounting information: done
Montez votre lv0 :
[root@centos8 ~]# mount -t ext3 /dev/vg0/lv0 /mnt/lvm
Vous allez maintenant copier le contenu de votre répertoire /home vers /mnt/lvm.
Saisissez donc la commande pour copier le contenu de /home :
[root@centos8 ~]# cp -a /home /mnt/lvm
Constatez ensuite le contenu de /mnt/lvm :
[root@centos8 ~]# ls -l /mnt/lvm total 14 drwxr-xr-x. 5 root root 1024 Apr 20 14:35 home drwx------. 2 root root 12288 May 26 17:00 lost+found
Une particularité du volume logique est la capacité de d'être aggrandi ou réduit sans pertes de données. Commencez par constater la taille totale du volume :
[root@centos8 ~]# df -h /mnt/lvm Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg0-lv0 333M 17M 314M 1% /mnt/lvm
Dans la cas de notre exemple, la taille est de 333 Mo avec 17 Mo occupé.
LAB #4 - Etendre un Volume Logique à Chaud
Pour agrandir un volume logique, le paquet lvm2 contient les commandes lvextend et resize2fs :
[root@centos8 ~]# lvextend -L +100M /dev/vg0/lv0 Rounding size to boundary between physical extents: 104.00 MiB. Size of logical volume vg0/lv0 changed from 352.00 MiB (44 extents) to 456.00 MiB (57 extents). Logical volume vg0/lv0 successfully resized.
Important - Notez que l'agrandissement du volume est un multiple du PE.
Les options de la commande lvextend sont :
[root@centos8 ~]# lvextend --help lvextend - Add space to a logical volume Extend an LV by a specified size. lvextend -L|--size [+]Size[m|UNIT] LV [ -l|--extents [+]Number[PERCENT] ] [ -r|--resizefs ] [ -i|--stripes Number ] [ -I|--stripesize Size[k|UNIT] ] [ --poolmetadatasize [+]Size[m|UNIT] ] [ COMMON_OPTIONS ] [ PV ... ] Extend an LV by specified PV extents. lvextend LV PV ... [ -r|--resizefs ] [ -i|--stripes Number ] [ -I|--stripesize Size[k|UNIT] ] [ COMMON_OPTIONS ] Extend a pool metadata SubLV by a specified size. lvextend --poolmetadatasize [+]Size[m|UNIT] LV_thinpool [ -i|--stripes Number ] [ -I|--stripesize Size[k|UNIT] ] [ COMMON_OPTIONS ] [ PV ... ] Extend an LV according to a predefined policy. lvextend --usepolicies LV_snapshot_thinpool [ -r|--resizefs ] [ COMMON_OPTIONS ] [ PV ... ] Common options for command: [ -A|--autobackup y|n ] [ -f|--force ] [ -m|--mirrors Number ] [ -n|--nofsck ] [ --alloc contiguous|cling|cling_by_tags|normal|anywhere|inherit ] [ --nosync ] [ --noudevsync ] [ --reportformat basic|json ] [ --type linear|striped|snapshot|mirror|raid|thin|cache|vdo|thin-pool|cache-pool|vdo-pool ] Common options for lvm: [ -d|--debug ] [ -h|--help ] [ -q|--quiet ] [ -v|--verbose ] [ -y|--yes ] [ -t|--test ] [ --commandprofile String ] [ --config String ] [ --driverloaded y|n ] [ --nolocking ] [ --lockopt String ] [ --longhelp ] [ --profile String ] [ --version ] Use --longhelp to show all options and advanced commands.
Le volume ayant été agrandi, il est necessaire maintenant d'agrandir le filesystem qui s'y trouve :
[root@centos8 ~]# resize2fs /dev/vg0/lv0 resize2fs 1.45.6 (20-Mar-2020) Filesystem at /dev/vg0/lv0 is mounted on /mnt/lvm; on-line resizing required old_desc_blocks = 2, new_desc_blocks = 2 The filesystem on /dev/vg0/lv0 is now 466944 (1k) blocks long.
Constatez maintenant la modification de la taille du volume :
[root@centos8 ~]# df -h /mnt/lvm Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg0-lv0 434M 17M 395M 5% /mnt/lvm
Vous noterez que la taille a augmentée mais que les données sont toujours présentes.
LAB #5 - Snapshots
Un snapshot est un instantané d'un système de fichiers. Dans cet exemple, vous allez créer un snapshot de votre lv0 :
Avant de commencer, créez un fichier de 10Mo dans le volume :
[root@centos8 ~]# dd if=/dev/zero of=/mnt/lvm/10M bs=1048576 count=10 10+0 records in 10+0 records out 10485760 bytes (10 MB, 10 MiB) copied, 0.0281282 s, 373 MB/s
Créez maintenant un snapshot :
[root@centos8 ~]# lvcreate -s -L 18M -n testsnap /dev/vg0/lv0 Rounding up size to full physical extent 24.00 MiB Logical volume "testsnap" created.
Pour avoir une confirmation de la création du snapshot, utilisez la commande lvs :
[root@centos8 ~]# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert root cl_centos8 -wi-ao---- 27.79g swap cl_centos8 -wi-ao---- 3.20g lv0 vg0 owi-aos--- 456.00m testsnap vg0 swi-a-s--- 24.00m lv0 0.05
Important - Notez que le snapshot est créé dans le même VG que le LV d'origine.
Les options de la commande lvs sont :
[root@centos8 ~]# lvs --help lvs - Display information about logical volumes lvs [ -H|--history ] [ -a|--all ] [ -o|--options String ] [ -S|--select String ] [ -O|--sort String ] [ --segments ] [ --aligned ] [ --binary ] [ --configreport log|vg|lv|pv|pvseg|seg ] [ --foreign ] [ --ignorelockingfailure ] [ --logonly ] [ --nameprefixes ] [ --noheadings ] [ --nosuffix ] [ --readonly ] [ --reportformat basic|json ] [ --rows ] [ --separator String ] [ --shared ] [ --unbuffered ] [ --units r|R|h|H|b|B|s|S|k|K|m|M|g|G|t|T|p|P|e|E ] [ --unquoted ] [ COMMON_OPTIONS ] [ VG|LV|Tag ... ] Common options for lvm: [ -d|--debug ] [ -h|--help ] [ -q|--quiet ] [ -v|--verbose ] [ -y|--yes ] [ -t|--test ] [ --commandprofile String ] [ --config String ] [ --driverloaded y|n ] [ --nolocking ] [ --lockopt String ] [ --longhelp ] [ --profile String ] [ --version ] Use --longhelp to show all options and advanced commands.
Créez maintenant un répertoire pour monter le snapshot :
[root@centos8 ~]# mkdir /mnt/testsnap
Montez le snapshot :
[root@centos8 ~]# mount /dev/vg0/testsnap /mnt/testsnap
Comparez le volume d'origine et le snapshot :
[root@centos8 ~]# ls -l /mnt/lvm total 10296 -rw-r--r--. 1 root root 10485760 Jun 24 04:41 10M drwxr-xr-x. 3 root root 1024 Jun 16 06:39 home drwx------. 2 root root 12288 Jun 24 04:20 lost+found [root@centos8 ~]# ls -l /mnt/testsnap/ total 10296 -rw-r--r--. 1 root root 10485760 Jun 24 04:41 10M drwxr-xr-x. 3 root root 1024 Jun 16 06:39 home drwx------. 2 root root 12288 Jun 24 04:20 lost+found
Supprimez maintenant le fichier 10M de votre volume d'origine :
[root@centos8 ~]# rm /mnt/lvm/10M rm: remove regular file '/mnt/lvm/10M'? y
Constatez le résultat de cette suppression :
[root@centos8 ~]# df -Ph /mnt/lvm Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg0-lv0 434M 17M 395M 5% /mnt/lvm [root@centos8 ~]# df -Ph /mnt/testsnap/ Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg0-testsnap 434M 27M 385M 7% /mnt/testsnap [root@centos8 ~]# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert root cl_centos8 -wi-ao---- 27.79g swap cl_centos8 -wi-ao---- 3.20g lv0 vg0 owi-aos--- 456.00m testsnap vg0 swi-aos--- 24.00m lv0 0.24
A Faire - Restaurez le fichier 10M à partir du snapshot.
LAB #6 - Suppression des Volumes
La suppression d'un volume logique se fait grace à la commande lvremove :
[root@centos8 ~]# umount /mnt/testsnap/ [root@centos8 ~]# lvremove /dev/vg0/testsnap Do you really want to remove active logical volume vg0/testsnap? [y/n]: y Logical volume "testsnap" successfully removed [root@centos8 ~]# umount /mnt/lvm [root@centos8 ~]# lvremove /dev/vg0/lv0 Do you really want to remove active logical volume vg0/lv0? [y/n]: y Logical volume "lv0" successfully removed
Important - Notez que cette opération necéssite à ce que le volume logique soit démonté.
Les options de la commande lvremove sont :
[root@centos8 ~]# lvremove --help lvremove - Remove logical volume(s) from the system lvremove VG|LV|Tag|Select ... [ -A|--autobackup y|n ] [ -f|--force ] [ -S|--select String ] [ --nohistory ] [ --noudevsync ] [ --reportformat basic|json ] [ COMMON_OPTIONS ] Common options for lvm: [ -d|--debug ] [ -h|--help ] [ -q|--quiet ] [ -v|--verbose ] [ -y|--yes ] [ -t|--test ] [ --commandprofile String ] [ --config String ] [ --driverloaded y|n ] [ --nolocking ] [ --lockopt String ] [ --longhelp ] [ --profile String ] [ --version ] Use --longhelp to show all options and advanced commands
Le Volume Group peut aussi être supprimé :
[root@centos8 ~]# vgremove vg0 Volume group "vg0" successfully removed
Les options de la commande vgremove sont :
[root@centos8 ~]# vgremove --help vgremove - Remove volume group(s) vgremove VG|Tag|Select ... [ -f|--force ] [ -S|--select String ] [ --noudevsync ] [ --reportformat basic|json ] [ COMMON_OPTIONS ] Common options for lvm: [ -d|--debug ] [ -h|--help ] [ -q|--quiet ] [ -v|--verbose ] [ -y|--yes ] [ -t|--test ] [ --commandprofile String ] [ --config String ] [ --driverloaded y|n ] [ --nolocking ] [ --lockopt String ] [ --longhelp ] [ --profile String ] [ --version ] Use --longhelp to show all options and advanced commands.
Ainsi que le volume physique :
[root@centos8 ~]# pvremove /dev/sdb6 /dev/sdb7 /dev/sdb9 Labels on physical volume "/dev/sdb6" successfully wiped. Labels on physical volume "/dev/sdb7" successfully wiped. Labels on physical volume "/dev/sdb9" successfully wiped.
Les options de la commande pvremove sont :
[root@centos8 ~]# pvremove --help pvremove - Remove LVM label(s) from physical volume(s) pvremove PV ... [ -f|--force ] [ --reportformat basic|json ] [ COMMON_OPTIONS ] Common options for lvm: [ -d|--debug ] [ -h|--help ] [ -q|--quiet ] [ -v|--verbose ] [ -y|--yes ] [ -t|--test ] [ --commandprofile String ] [ --config String ] [ --driverloaded y|n ] [ --nolocking ] [ --lockopt String ] [ --longhelp ] [ --profile String ] [ --version ] Use --longhelp to show all options and advanced commands.
LAB #7 - Volumes Logiques en Miroir
Re-créez maintenant votre Volume Group :
[root@centos8 ~]# pvcreate /dev/sdb6 /dev/sdb7 /dev/sdb9 Physical volume "/dev/sdb6" successfully created. Physical volume "/dev/sdb7" successfully created. Physical volume "/dev/sdb9" successfully created. [root@centos8 ~]# vgcreate -s 8M vg0 /dev/sdb6 /dev/sdb7 /dev/sdb9 Volume group "vg0" successfully created
Créez maintenant un Logical Volume en miroir grâce à l'option -m de la commande lvcreate, suivi du nombre de miroirs :
[root@centos8 ~]# lvcreate -m 1 -L 100M -n lv1 vg0 Rounding up size to full physical extent 104.00 MiB Logical volume "lv1" created.
Constatez maintenant la présence du miroir :
[root@centos8 ~]# lvdisplay -m /dev/vg0/lv1
--- Logical volume ---
LV Path /dev/vg0/lv1
LV Name lv1
VG Name vg0
LV UUID lJQQWs-n05T-pxzi-Zq2R-UzRI-kYZf-hsNPYQ
LV Write Access read/write
LV Creation host, time centos8.ittraining.loc, 2021-06-02 07:37:28 -0400
LV Status available
# open 0
LV Size 104.00 MiB
Current LE 13
Mirrored volumes 2
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:4
--- Segments ---
Logical extents 0 to 12:
Type raid1
Monitoring monitored
Raid Data LV 0
Logical volume lv1_rimage_0
Logical extents 0 to 12
Raid Data LV 1
Logical volume lv1_rimage_1
Logical extents 0 to 12
Raid Metadata LV 0 lv1_rmeta_0
Raid Metadata LV 1 lv1_rmeta_1
Le miroir s'étend sur plusieurs volumes physiques :
[root@centos8 ~]# pvdisplay -m /dev/sdb6 /dev/sdb7 /dev/sdb9
--- Physical volume ---
PV Name /dev/sdb6
VG Name vg0
PV Size 200.00 MiB / not usable 8.00 MiB
Allocatable yes
PE Size 8.00 MiB
Total PE 24
Free PE 10
Allocated PE 14
PV UUID lxuKRI-l3Dd-jhsv-OWtw-au2c-0ti0-XGnt1E
--- Physical Segments ---
Physical extent 0 to 0:
Logical volume /dev/vg0/lv1_rmeta_0
Logical extents 0 to 0
Physical extent 1 to 13:
Logical volume /dev/vg0/lv1_rimage_0
Logical extents 0 to 12
Physical extent 14 to 23:
FREE
--- Physical volume ---
PV Name /dev/sdb7
VG Name vg0
PV Size 300.00 MiB / not usable 4.00 MiB
Allocatable yes
PE Size 8.00 MiB
Total PE 37
Free PE 23
Allocated PE 14
PV UUID QDmfcX-Pv8o-hapq-TJOI-RaPH-qecT-VUMY4v
--- Physical Segments ---
Physical extent 0 to 0:
Logical volume /dev/vg0/lv1_rmeta_1
Logical extents 0 to 0
Physical extent 1 to 13:
Logical volume /dev/vg0/lv1_rimage_1
Logical extents 0 to 12
Physical extent 14 to 36:
FREE
--- Physical volume ---
PV Name /dev/sdb9
VG Name vg0
PV Size 400.00 MiB / not usable 8.00 MiB
Allocatable yes
PE Size 8.00 MiB
Total PE 49
Free PE 49
Allocated PE 0
PV UUID ZTQV1b-Ha76-BQtB-zJEU-kfyK-ausJ-CxnRwg
--- Physical Segments ---
Physical extent 0 to 48:
FREE
La suppression du miroir se fait en utilisant la commande lvconvert en indiquant quel volume physique doit être vidé de son contenu :
[root@centos8 ~]# lvconvert -m 0 /dev/vg0/lv1 /dev/sdb7 Are you sure you want to convert raid1 LV vg0/lv1 to type linear losing all resilience? [y/n]: y Logical volume vg0/lv1 successfully converted.
De même, il est possible de créer un miroir pour un volume logique existant :
[root@centos8 ~]# lvconvert -m 1 /dev/vg0/lv1 Are you sure you want to convert linear LV vg0/lv1 to raid1 with 2 images enhancing resilience? [y/n]: y Logical volume vg0/lv1 successfully converted.
Supprimez de nouveau votre miroir :
[root@centos8 ~]# lvconvert -m 0 /dev/vg0/lv1 /dev/sdb7 Are you sure you want to convert raid1 LV vg0/lv1 to type linear losing all resilience? [y/n]: y Logical volume vg0/lv1 successfully converted.
Les options de la commande lvconvert sont :
[root@centos8 ~]# lvconvert --help lvconvert - Change logical volume layout Convert LV to linear. lvconvert --type linear LV [ COMMON_OPTIONS ] [ PV ... ] Convert LV to striped. lvconvert --type striped LV [ -I|--stripesize Size[k|UNIT] ] [ -R|--regionsize Size[m|UNIT] ] [ -i|--interval Number ] [ --stripes Number ] [ COMMON_OPTIONS ] [ PV ... ] Convert LV to type mirror (also see type raid1), lvconvert --type mirror LV [ -m|--mirrors [+|-]Number ] [ -I|--stripesize Size[k|UNIT] ] [ -R|--regionsize Size[m|UNIT] ] [ -i|--interval Number ] [ --stripes Number ] [ --mirrorlog core|disk ] [ COMMON_OPTIONS ] [ PV ... ] Convert LV to raid or change raid layout (a specific raid level must be used, e.g. raid1). lvconvert --type raid LV [ -m|--mirrors [+|-]Number ] [ -I|--stripesize Size[k|UNIT] ] [ -R|--regionsize Size[m|UNIT] ] [ -i|--interval Number ] [ --stripes Number ] [ COMMON_OPTIONS ] [ PV ... ] Convert LV to raid1 or mirror, or change number of mirror images. lvconvert -m|--mirrors [+|-]Number LV [ -R|--regionsize Size[m|UNIT] ] [ -i|--interval Number ] [ --mirrorlog core|disk ] [ COMMON_OPTIONS ] [ PV ... ] Convert raid LV to change number of stripe images. lvconvert --stripes Number LV_raid [ -i|--interval Number ] [ -R|--regionsize Size[m|UNIT] ] [ -I|--stripesize Size[k|UNIT] ] [ COMMON_OPTIONS ] [ PV ... ] Convert raid LV to change the stripe size. lvconvert -I|--stripesize Size[k|UNIT] LV_raid [ -i|--interval Number ] [ -R|--regionsize Size[m|UNIT] ] [ COMMON_OPTIONS ] Split images from a raid1 or mirror LV and use them to create a new LV. lvconvert --splitmirrors Number -n|--name LV_new LV_cache_mirror_raid1 [ COMMON_OPTIONS ] [ PV ... ] Split images from a raid1 LV and track changes to origin for later merge. lvconvert --splitmirrors Number --trackchanges LV_cache_raid1 [ COMMON_OPTIONS ] [ PV ... ] Merge LV images that were split from a raid1 LV. lvconvert --mergemirrors VG|LV_linear_raid|Tag ... [ COMMON_OPTIONS ] Convert LV to a thin LV, using the original LV as an external origin. lvconvert --type thin --thinpool LV LV_linear_striped_thin_cache_raid [ -T|--thin ] [ -r|--readahead auto|none|Number ] [ -c|--chunksize Size[k|UNIT] ] [ -Z|--zero y|n ] [ --originname LV_new ] [ --poolmetadata LV ] [ --poolmetadatasize Size[m|UNIT] ] [ --poolmetadataspare y|n ] [ --metadataprofile String ] [ COMMON_OPTIONS ] Attach a cache pool to an LV, converts the LV to type cache. lvconvert --type cache --cachepool LV LV_linear_striped_thinpool_vdo_vdopool_vdopooldata_raid [ -H|--cache ] [ -Z|--zero y|n ] [ -r|--readahead auto|none|Number ] [ -c|--chunksize Size[k|UNIT] ] [ --cachemetadataformat auto|1|2 ] [ --cachemode writethrough|writeback|passthrough ] [ --cachepolicy String ] [ --cachesettings String ] [ --poolmetadata LV ] [ --poolmetadatasize Size[m|UNIT] ] [ --poolmetadataspare y|n ] [ --metadataprofile String ] [ COMMON_OPTIONS ] Attach a writecache to an LV, converts the LV to type writecache. lvconvert --type writecache --cachevol LV LV_linear_striped_raid [ --cachesettings String ] [ COMMON_OPTIONS ] Attach a cache to an LV, converts the LV to type cache. lvconvert --type cache --cachevol LV LV_linear_striped_thinpool_raid [ -H|--cache ] [ -Z|--zero y|n ] [ -c|--chunksize Size[k|UNIT] ] [ --cachemetadataformat auto|1|2 ] [ --cachemode writethrough|writeback|passthrough ] [ --cachepolicy String ] [ --cachesettings String ] [ --poolmetadatasize Size[m|UNIT] ] [ COMMON_OPTIONS ] Add a writecache to an LV, using a specified cache device. lvconvert --type writecache --cachedevice PV LV_linear_striped_raid [ --cachesize Size[m|UNIT] ] [ --cachesettings String ] [ COMMON_OPTIONS ] Add a cache to an LV, using a specified cache device. lvconvert --type cache --cachedevice PV LV_linear_striped_thinpool_raid [ --cachesize Size[m|UNIT] ] [ --cachesettings String ] [ COMMON_OPTIONS ] Convert LV to type thin-pool. lvconvert --type thin-pool LV_linear_striped_cache_raid [ -I|--stripesize Size[k|UNIT] ] [ -r|--readahead auto|none|Number ] [ -c|--chunksize Size[k|UNIT] ] [ -Z|--zero y|n ] [ --stripes Number ] [ --discards passdown|nopassdown|ignore ] [ --poolmetadata LV ] [ --poolmetadatasize Size[m|UNIT] ] [ --poolmetadataspare y|n ] [ --metadataprofile String ] [ COMMON_OPTIONS ] [ PV ... ] Convert LV to type cache-pool. lvconvert --type cache-pool LV_linear_striped_raid [ -Z|--zero y|n ] [ -r|--readahead auto|none|Number ] [ -c|--chunksize Size[k|UNIT] ] [ --cachemetadataformat auto|1|2 ] [ --cachemode writethrough|writeback|passthrough ] [ --cachepolicy String ] [ --cachesettings String ] [ --poolmetadata LV ] [ --poolmetadatasize Size[m|UNIT] ] [ --poolmetadataspare y|n ] [ --metadataprofile String ] [ COMMON_OPTIONS ] [ PV ... ] Convert LV to type vdopool. lvconvert --type vdo-pool LV_linear_striped_cache_raid [ -n|--name LV_new ] [ -V|--virtualsize Size[m|UNIT] ] [ --compression y|n ] [ --deduplication y|n ] [ COMMON_OPTIONS ] Detach a cache from an LV. lvconvert --splitcache LV_thinpool_cache_cachepool_vdopool_writecache [ COMMON_OPTIONS ] Merge thin LV into its origin LV. lvconvert --mergethin LV_thin ... [ COMMON_OPTIONS ] Merge COW snapshot LV into its origin. lvconvert --mergesnapshot LV_snapshot ... [ -i|--interval Number ] [ COMMON_OPTIONS ] Combine a former COW snapshot (second arg) with a former origin LV (first arg) to reverse a splitsnapshot command. lvconvert --type snapshot LV LV_linear_striped [ -s|--snapshot ] [ -c|--chunksize Size[k|UNIT] ] [ -Z|--zero y|n ] [ COMMON_OPTIONS ] Replace failed PVs in a raid or mirror LV. Repair a thin pool. Repair a cache pool. lvconvert --repair LV_thinpool_cache_cachepool_mirror_raid [ -i|--interval Number ] [ --usepolicies ] [ --poolmetadataspare y|n ] [ COMMON_OPTIONS ] [ PV ... ] Replace specific PV(s) in a raid LV with another PV. lvconvert --replace PV LV_raid [ COMMON_OPTIONS ] [ PV ... ] Poll LV to continue conversion. lvconvert --startpoll LV_mirror_raid [ COMMON_OPTIONS ] Add or remove data integrity checksums to raid images. lvconvert --raidintegrity y|n LV_raid [ --raidintegritymode String ] [ --raidintegrityblocksize Number ] [ COMMON_OPTIONS ] [ PV ... ] Common options for command: [ -b|--background ] [ -f|--force ] [ --alloc contiguous|cling|cling_by_tags|normal|anywhere|inherit ] [ --noudevsync ] Common options for lvm: [ -d|--debug ] [ -h|--help ] [ -q|--quiet ] [ -v|--verbose ] [ -y|--yes ] [ -t|--test ] [ --commandprofile String ] [ --config String ] [ --driverloaded y|n ] [ --nolocking ] [ --lockopt String ] [ --longhelp ] [ --profile String ] [ --version ] Use --longhelp to show all options and advanced commands.
LAB #8 - Modifier les Attributs LVM
En cas de présence d'un miroir, la commande lvs indique la présence du miroir dans la colonne Attr avec la lettre m :
[root@centos8 ~]# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert root cl_centos8 -wi-ao---- 27.79g swap cl_centos8 -wi-ao---- 3.20g lv1 vg0 -wi-a----- 104.00m
Consultez cette page pour comprendre les attributs.
La commande equivalente pour les Volume Groups est vgs :
[root@centos8 ~]# vgs VG #PV #LV #SN Attr VSize VFree cl_centos8 1 2 0 wz--n- <31.00g 0 vg0 3 1 0 wz--n- 880.00m 776.00m
Consultez cette page pour comprendre les attributs.
La commande equivalente pour les Physical Volumes est pvs :
[root@centos8 ~]# pvs PV VG Fmt Attr PSize PFree /dev/sda2 cl_centos8 lvm2 a-- <31.00g 0 /dev/sdb6 vg0 lvm2 a-- 192.00m 88.00m /dev/sdb7 vg0 lvm2 a-- 296.00m 296.00m /dev/sdb9 vg0 lvm2 a-- 392.00m 392.00m
Consultez cette page pour comprendre les attributs.
Les commandes lvchange, vgchange et pvchange permettent de modifier les attributs des Logical Volumes, Volume Groups et Physical Volumes respectivement.
Par exemple, pour rendre inutilisable un Logical Volume, il convient d'enlever l'attribut a :
[root@centos8 ~]# lvchange -a n /dev/vg0/lv1
Pour faire l'inverse il convient de saisir la commande suivante :
[root@centos8 ~]# lvchange -a y /dev/vg0/lv1
Les options de la commande lvchange sont :
[root@centos8 ~]# lvchange --help lvchange - Change the attributes of logical volume(s) Change a general LV attribute. For options listed in parentheses, any one is required, after which the others are optional. lvchange ( -C|--contiguous y|n, -p|--permission rw|r, -r|--readahead auto|none|Number, -k|--setactivationskip y|n, -Z|--zero y|n, -M|--persistent n, --addtag Tag, --deltag Tag, --alloc contiguous|cling|cling_by_tags|normal|anywhere|inherit, --compression y|n, --deduplication y|n, --detachprofile, --metadataprofile String, --profile String, --errorwhenfull y|n, --discards passdown|nopassdown|ignore, --cachemode writethrough|writeback|passthrough, --cachepolicy String, --cachesettings String, --minrecoveryrate Size[k|UNIT], --maxrecoveryrate Size[k|UNIT], --writebehind Number, --writemostly PV[:t|n|y] ) VG|LV|Tag|Select ... [ -a|--activate y|n|ay ] [ --poll y|n ] [ --monitor y|n ] [ COMMON_OPTIONS ] Resyncronize a mirror or raid LV. Use to reset 'R' attribute on a not initially synchronized LV. lvchange --resync VG|LV_mirror_raid|Tag|Select ... [ -a|--activate y|n|ay ] [ COMMON_OPTIONS ] Resynchronize or check a raid LV. lvchange --syncaction check|repair VG|LV_raid|Tag|Select ... [ COMMON_OPTIONS ] Reconstruct data on specific PVs of a raid LV. lvchange --rebuild PV VG|LV_raid|Tag|Select ... [ COMMON_OPTIONS ] Activate or deactivate an LV. lvchange -a|--activate y|n|ay VG|LV|Tag|Select ... [ -P|--partial ] [ -K|--ignoreactivationskip ] [ --activationmode partial|degraded|complete ] [ --poll y|n ] [ --monitor y|n ] [ --ignorelockingfailure ] [ --sysinit ] [ --readonly ] [ COMMON_OPTIONS ] Reactivate an LV using the latest metadata. lvchange --refresh VG|LV|Tag|Select ... [ -P|--partial ] [ --activationmode partial|degraded|complete ] [ --poll y|n ] [ --monitor y|n ] [ COMMON_OPTIONS ] Start or stop monitoring an LV from dmeventd. lvchange --monitor y|n VG|LV|Tag|Select ... [ COMMON_OPTIONS ] Start or stop processing an LV conversion. lvchange --poll y|n VG|LV|Tag|Select ... [ --monitor y|n ] [ COMMON_OPTIONS ] Make the minor device number persistent for an LV. lvchange -M|--persistent y --minor Number LV [ -j|--major Number ] [ -a|--activate y|n|ay ] [ --poll y|n ] [ --monitor y|n ] [ COMMON_OPTIONS ] Common options for command: [ -A|--autobackup y|n ] [ -f|--force ] [ -S|--select String ] [ --ignoremonitoring ] [ --noudevsync ] [ --reportformat basic|json ] Common options for lvm: [ -d|--debug ] [ -h|--help ] [ -q|--quiet ] [ -v|--verbose ] [ -y|--yes ] [ -t|--test ] [ --commandprofile String ] [ --config String ] [ --driverloaded y|n ] [ --nolocking ] [ --lockopt String ] [ --longhelp ] [ --profile String ] [ --version ] Use --longhelp to show all options and advanced commands.
LAB #9 - Volumes Logiques en Bandes
Un volume logique en bandes est créé pour augmenter, comme dans le cas du RAID, les performances des entrées et sorties. Pour créer ce volume, la commande lvcreate prend deux option supplémentaires :
- -i - indique le nombre de volumes de bandes,
- -I - indique la taille en Ko de chaque bande.
Saisissez donc la commande suivante :
[root@centos8 ~]# lvcreate -i2 -I64 -n lv2 -L 100M vg0 /dev/sdb7 /dev/sdb9 Rounding up size to full physical extent 104.00 MiB Rounding size 104.00 MiB (13 extents) up to stripe boundary size 112.00 MiB(14 extents). Logical volume "lv2" created.
Constatez la présence de vos bandes sur /dev/sda7 et sur /dev/sda9 :
[root@centos8 ~]# lvdisplay -m /dev/vg0/lv2
--- Logical volume ---
LV Path /dev/vg0/lv2
LV Name lv2
VG Name vg0
LV UUID MmXbPt-ZF8u-rnIv-3YU9-m64J-RCz2-6NzAuG
LV Write Access read/write
LV Creation host, time centos8.ittraining.loc, 2021-06-02 07:47:38 -0400
LV Status available
# open 0
LV Size 112.00 MiB
Current LE 14
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:1
--- Segments ---
Logical extents 0 to 13:
Type striped
Stripes 2
Stripe size 64.00 KiB
Stripe 0:
Physical volume /dev/sdb7
Physical extents 0 to 6
Stripe 1:
Physical volume /dev/sdb9
Physical extents 0 to 6
Utilisez maintenant la commande lvs pour visualiser les volumes physiques utilisés par le volume logique :
[root@centos8 ~]# lvs -o +devices LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert Devices root cl_centos8 -wi-ao---- 27.79g /dev/sda2(820) swap cl_centos8 -wi-ao---- 3.20g /dev/sda2(0) lv1 vg0 -wi-a----- 104.00m /dev/sdb6(1) lv2 vg0 -wi-a----- 112.00m /dev/sdb7(0),/dev/sdb9(0)
LAB #10 - Gérer les Métadonnées
Les métadonnées pour chaque Volume Group sont stockés dans un fichier texte au nom du Volume Group dans le répertoire /etc/lvm/backup :
[root@centos8 ~]# cat /etc/lvm/backup/vg0
# Generated by LVM2 version 2.03.09(2)-RHEL8 (2020-05-28): Wed Jun 2 07:47:38 2021
contents = "Text Format Volume Group"
version = 1
description = "Created *after* executing 'lvcreate -i2 -I64 -n lv2 -L 100M vg0 /dev/sdb7 /dev/sdb9'"
creation_host = "centos8.ittraining.loc" # Linux centos8.ittraining.loc 4.18.0-240.22.1.el8_3.x86_64 #1 SMP Thu Apr 8 19:01:30 UTC 2021 x86_64
creation_time = 1622634458 # Wed Jun 2 07:47:38 2021
vg0 {
id = "TDXUip-c3yg-J83l-Z30x-zcsJ-Rbvl-gjFvfd"
seqno = 11
format = "lvm2" # informational
status = ["RESIZEABLE", "READ", "WRITE"]
flags = []
extent_size = 16384 # 8 Megabytes
max_lv = 0
max_pv = 0
metadata_copies = 0
physical_volumes {
pv0 {
id = "lxuKRI-l3Dd-jhsv-OWtw-au2c-0ti0-XGnt1E"
device = "/dev/sdb6" # Hint only
status = ["ALLOCATABLE"]
flags = []
dev_size = 409600 # 200 Megabytes
pe_start = 2048
pe_count = 24 # 192 Megabytes
}
pv1 {
id = "QDmfcX-Pv8o-hapq-TJOI-RaPH-qecT-VUMY4v"
device = "/dev/sdb7" # Hint only
status = ["ALLOCATABLE"]
flags = []
dev_size = 614400 # 300 Megabytes
pe_start = 2048
pe_count = 37 # 296 Megabytes
}
pv2 {
id = "ZTQV1b-Ha76-BQtB-zJEU-kfyK-ausJ-CxnRwg"
device = "/dev/sdb9" # Hint only
status = ["ALLOCATABLE"]
flags = []
dev_size = 819200 # 400 Megabytes
pe_start = 2048
pe_count = 49 # 392 Megabytes
}
}
logical_volumes {
lv1 {
id = "lJQQWs-n05T-pxzi-Zq2R-UzRI-kYZf-hsNPYQ"
status = ["READ", "WRITE", "VISIBLE"]
flags = []
creation_time = 1622633848 # 2021-06-02 07:37:28 -0400
creation_host = "centos8.ittraining.loc"
segment_count = 1
segment1 {
start_extent = 0
extent_count = 13 # 104 Megabytes
type = "striped"
stripe_count = 1 # linear
stripes = [
"pv0", 1
]
}
}
lv2 {
id = "MmXbPt-ZF8u-rnIv-3YU9-m64J-RCz2-6NzAuG"
status = ["READ", "WRITE", "VISIBLE"]
flags = []
creation_time = 1622634458 # 2021-06-02 07:47:38 -0400
creation_host = "centos8.ittraining.loc"
segment_count = 1
segment1 {
start_extent = 0
extent_count = 14 # 112 Megabytes
type = "striped"
stripe_count = 2
stripe_size = 128 # 64 Kilobytes
stripes = [
"pv1", 0,
"pv2", 0
]
}
}
}
}
Des archives sont créées lors de chaque modification d'un groupe de volumes et elles sont placés dans le répertoire /etc/lvm/archives :
[root@centos8 ~]# ls /etc/lvm/archive/ vg0_00000-427117660.vg vg0_00002-2064899457.vg vg0_00004-5061041.vg vg0_00006-1956284179.vg vg0_00008-708301076.vg vg0_00010-1200598227.vg vg0_00012-854342401.vg vg0_00001-1993147316.vg vg0_00003-1757437978.vg vg0_00005-116946854.vg vg0_00007-1006758937.vg vg0_00009-1054420117.vg vg0_00011-973084311.vg
La commande vgcfgbackup est utilisée pour sauvegarder les métadonnées manuellement dans le fichier /etc/lvm/backup/nom_du_volume_group :
La commande vgcfgrestore permet de restaurer une sauvegarde. Sans l'option -f pour spécifier la sauvegarde à restaurer, cette commande renvoie la liste des sauvegardes disponibles :
[root@centos8 ~]# vgcfgbackup vg0 Volume group "vg0" successfully backed up.
Il est aussi possible de modifier l'emplacement de la sauvegarde avec l'option -f de la commande :
[root@centos8 ~]# vgcfgbackup -f /tmp/vg0_backup vg0 Volume group "vg0" successfully backed up.
Par contre, toute sauvegarde en dehors des répertoires par défaut n'est pas visible dans la sortie de la commande vgcfgrestore –list :
[root@centos8 ~]# vgcfgrestore --list vg0 File: /etc/lvm/archive/vg0_00000-427117660.vg VG name: vg0 Description: Created *before* executing 'vgcreate -s 8M vg0 /dev/sdb6 /dev/sdb7 /dev/sdb9' Backup Time: Wed May 26 10:43:14 2021 File: /etc/lvm/archive/vg0_00001-1993147316.vg VG name: vg0 Description: Created *before* executing 'lvcreate -L 350 -n lv0 vg0' Backup Time: Wed May 26 16:56:31 2021 File: /etc/lvm/archive/vg0_00002-2064899457.vg VG name: vg0 Description: Created *before* executing 'lvextend -L +100M /dev/vg0/lv0' Backup Time: Wed May 26 22:12:15 2021 File: /etc/lvm/archive/vg0_00003-1757437978.vg VG name: vg0 Description: Created *before* executing 'lvcreate -s -L 13M -n testsnap /dev/vg0/lv0' Backup Time: Wed May 26 22:19:25 2021 File: /etc/lvm/archive/vg0_00004-5061041.vg VG name: vg0 Description: Created *before* executing 'lvremove /dev/vg0/testsnap' Backup Time: Wed May 26 22:38:37 2021 File: /etc/lvm/archive/vg0_00005-116946854.vg VG name: vg0 Description: Created *before* executing 'lvremove /dev/vg0/lv0' Backup Time: Wed May 26 22:42:18 2021 File: /etc/lvm/archive/vg0_00006-1956284179.vg VG name: vg0 Description: Created *before* executing 'vgremove vg0' Backup Time: Wed May 26 22:43:49 2021 File: /etc/lvm/archive/vg0_00007-1006758937.vg VG name: vg0 Description: Created *before* executing 'vgcreate -s 8M vg0 /dev/sdb6 /dev/sdb7 /dev/sdb9' Backup Time: Wed Jun 2 07:37:07 2021 File: /etc/lvm/archive/vg0_00008-708301076.vg VG name: vg0 Description: Created *before* executing 'lvcreate -m 1 -L 100M -n lv1 vg0' Backup Time: Wed Jun 2 07:37:28 2021 File: /etc/lvm/archive/vg0_00009-1054420117.vg VG name: vg0 Description: Created *before* executing 'lvconvert -m 0 /dev/vg0/lv1 /dev/sdb7' Backup Time: Wed Jun 2 07:41:04 2021 File: /etc/lvm/archive/vg0_00010-1200598227.vg VG name: vg0 Description: Created *before* executing 'lvconvert -m 1 /dev/vg0/lv1' Backup Time: Wed Jun 2 07:41:53 2021 File: /etc/lvm/archive/vg0_00011-973084311.vg VG name: vg0 Description: Created *before* executing 'lvconvert -m 0 /dev/vg0/lv1 /dev/sdb7' Backup Time: Wed Jun 2 07:42:23 2021 File: /etc/lvm/archive/vg0_00012-854342401.vg VG name: vg0 Description: Created *before* executing 'lvcreate -i2 -I64 -n lv2 -L 100M vg0 /dev/sdb7 /dev/sdb9' Backup Time: Wed Jun 2 07:47:38 2021 File: /etc/lvm/backup/vg0 VG name: vg0 Description: Created *after* executing 'vgcfgbackup vg0' Backup Time: Wed Jun 2 07:50:57 2021
LAB #20 - Créer un Système de Fichiers ISO
La Commande mkisofs
Pour créer un fichier ISO à partir d'une arborescence de fichiers, il convient d'utiliser la commande mkisofs :
[root@centos8 ~]# cd /tmp [root@centos8 tmp]# mkisofs -r -T -o tmp.iso . I: -input-charset not specified, using utf-8 (detected in locale settings) Total translation table size: 1827 Total rockridge attributes bytes: 1976 Total directory bytes: 14336 Path table size(bytes): 122 Max brk space used 1c000 186 extents written (0 MB)
Le fichier ISO peut être monter en utilisant un périphérique de type loop :
[root@centos8 tmp]# mount tmp.iso /mnt -o loop mount: /mnt: WARNING: device write-protected, mounted read-only. [root@centos8 tmp]# ls /mnt systemd-private-192104a9224f499286f5adb5754e9e04-chronyd.service-FI2YXs TRANS.TBL vg0_backup [root@centos8 tmp]# ls systemd-private-192104a9224f499286f5adb5754e9e04-chronyd.service-FI2YXs tmp.iso vg0_backup
Démontez maintenant le fichier ISO :
[root@centos8 tmp]# cd ~ [root@centos8 ~]# umount /tmp/tmp.iso
Options de la Commande mkisofs
Les options de cette commande sont :
[root@centos8 ~]# mkisofs --help
Usage: genisoimage [options] file...
Options:
-nobak Do not include backup files
-no-bak Do not include backup files
-abstract FILE Set Abstract filename
-A ID, -appid ID Set Application ID
-biblio FILE Set Bibliographic filename
-cache-inodes Cache inodes (needed to detect hard links)
-no-cache-inodes Do not cache inodes (if filesystem has no unique unides)
-check-oldnames Check all imported ISO9660 names from old session
-check-session FILE Check all ISO9660 names from previous session
-copyright FILE Set Copyright filename
-debug Set debug flag
-b FILE, -eltorito-boot FILE
Set El Torito boot image name
-e FILE, -efi-boot FILE Set EFI boot image name
-eltorito-alt-boot Start specifying alternative El Torito boot parameters
-B FILES, -sparc-boot FILES Set sparc boot image names
-sunx86-boot FILES Set sunx86 boot image names
-G FILE, -generic-boot FILE Set generic boot image name
-sparc-label label text Set sparc boot disk label
-sunx86-label label text Set sunx86 boot disk label
-c FILE, -eltorito-catalog FILE
Set El Torito boot catalog name
-C PARAMS, -cdrecord-params PARAMS
Magic paramters from cdrecord
-d, -omit-period Omit trailing periods from filenames (violates ISO9660)
-dir-mode mode Make the mode of all directories this mode.
-D, -disable-deep-relocation
Disable deep directory relocation (violates ISO9660)
-file-mode mode Make the mode of all plain files this mode.
-f, -follow-links Follow symbolic links
-gid gid Make the group owner of all files this gid.
-graft-points Allow to use graft points for filenames
-root DIR Set root directory for all new files and directories
-old-root DIR Set root directory in previous session that is searched for files
-help Print option help
-hide GLOBFILE Hide ISO9660/RR file
-hide-list FILE File with list of ISO9660/RR files to hide
-hidden GLOBFILE Set hidden attribute on ISO9660 file
-hidden-list FILE File with list of ISO9660 files with hidden attribute
-hide-joliet GLOBFILE Hide Joliet file
-hide-joliet-list FILE File with list of Joliet files to hide
-hide-joliet-trans-tbl Hide TRANS.TBL from Joliet tree
-hide-rr-moved Rename RR_MOVED to .rr_moved in Rock Ridge tree
-gui Switch behaviour for GUI
-i ADD_FILES No longer supported
-input-charset CHARSET Local input charset for file name conversion
-output-charset CHARSET Output charset for file name conversion
-iso-level LEVEL Set ISO9660 conformance level (1..3) or 4 for ISO9660 version 2
-J, -joliet Generate Joliet directory information
-joliet-long Allow Joliet file names to be 103 Unicode characters
-jcharset CHARSET Local charset for Joliet directory information
-l, -full-iso9660-filenames Allow full 31 character filenames for ISO9660 names
-max-iso9660-filenames Allow 37 character filenames for ISO9660 names (violates ISO9660)
-allow-limited-size Allow different file sizes in ISO9660/UDF on large files
-allow-leading-dots Allow ISO9660 filenames to start with '.' (violates ISO9660)
-ldots Allow ISO9660 filenames to start with '.' (violates ISO9660)
-L, -allow-leading-dots Allow ISO9660 filenames to start with '.' (violates ISO9660)
-log-file LOG_FILE Re-direct messages to LOG_FILE
-m GLOBFILE, -exclude GLOBFILE
Exclude file name
-exclude-list FILE File with list of file names to exclude
-pad Pad output to a multiple of 32k (default)
-no-pad Do not pad output to a multiple of 32k
-M FILE, -prev-session FILE Set path to previous session to merge
-dev SCSIdev Set path to previous session to merge
-N, -omit-version-number Omit version number from ISO9660 filename (violates ISO9660)
-new-dir-mode mode Mode used when creating new directories.
-force-rr Inhibit automatic Rock Ridge detection for previous session
-no-rr Inhibit reading of Rock Ridge attributes from previous session
-no-split-symlink-components
Inhibit splitting symlink components
-no-split-symlink-fields Inhibit splitting symlink fields
-o FILE, -output FILE Set output file name
-path-list FILE File with list of pathnames to process
-p PREP, -preparer PREP Set Volume preparer
-print-size Print estimated filesystem size and exit
-publisher PUB Set Volume publisher
-P PUB, -publisher PUB Set Volume publisher
-quiet Run quietly
-r, -rational-rock Generate rationalized Rock Ridge directory information
-R, -rock Generate Rock Ridge directory information
-s TYPE, -sectype TYPE Set output sector type to e.g. data/xa1/raw
-alpha-boot FILE Set alpha boot image name (relative to image root)
-hppa-cmdline CMDLINE Set hppa boot command line (relative to image root)
-hppa-kernel-32 FILE Set hppa 32-bit image name (relative to image root)
-hppa-kernel-64 FILE Set hppa 64-bit image name (relative to image root)
-hppa-bootloader FILE Set hppa boot loader file name (relative to image root)
-hppa-ramdisk FILE Set hppa ramdisk file name (relative to image root)
-mips-boot FILE Set mips boot image name (relative to image root)
-mipsel-boot FILE Set mipsel boot image name (relative to image root)
-jigdo-jigdo FILE Produce a jigdo .jigdo file as well as the .iso
-jigdo-template FILE Produce a jigdo .template file as well as the .iso
-jigdo-min-file-size SIZE Minimum size for a file to be listed in the jigdo file
-jigdo-force-md5 PATTERN Pattern(s) where files MUST match an externally-supplied MD5sum
-jigdo-exclude PATTERN Pattern(s) to exclude from the jigdo file
-jigdo-map PATTERN1=PATTERN2
Pattern(s) to map paths (e.g. Debian=/mirror/debian)
-md5-list FILE File containing MD5 sums of the files that should be checked
-jigdo-template-compress ALGORITHM
Choose to use gzip or bzip2 compression for template data; default is gzip
-checksum_algorithm_iso alg1,alg2,...
Specify the checksum types desired for the output image
-checksum_algorithm_template alg1,alg2,...
Specify the checksum types desired for the output jigdo template
-sort FILE Sort file content locations according to rules in FILE
-split-output Split output into files of approx. 1GB size
-stream-file-name FILE_NAME Set the stream file ISO9660 name (incl. version)
-stream-media-size # Set the size of your CD media in sectors
-sysid ID Set System ID
-T, -translation-table Generate translation tables for systems that don't understand long filenames
-table-name TABLE_NAME Translation table file name
-ucs-level LEVEL Set Joliet UCS level (1..3)
-udf Generate UDF file system
-dvd-video Generate DVD-Video compliant UDF file system
-uid uid Make the owner of all files this uid.
-U, -untranslated-filenames Allow Untranslated filenames (for HPUX & AIX - violates ISO9660). Forces -l, -d, -N, -allow-leading-dots, -relaxed-filenames, -allow-lowercase, -allow-multidot
-relaxed-filenames Allow 7 bit ASCII except lower case characters (violates ISO9660)
-no-iso-translate Do not translate illegal ISO characters '~', '-' and '#' (violates ISO9660)
-allow-lowercase Allow lower case characters in addition to the current character set (violates ISO9660)
-allow-multidot Allow more than one dot in filenames (e.g. .tar.gz) (violates ISO9660)
-use-fileversion LEVEL Use file version # from filesystem
-v, -verbose Verbose
-version Print the current version
-V ID, -volid ID Set Volume ID
-volset ID Set Volume set ID
-volset-size # Set Volume set size
-volset-seqno # Set Volume set sequence number
-x FILE, -old-exclude FILE Exclude file name(depreciated)
-hard-disk-boot Boot image is a hard disk image
-no-emul-boot Boot image is 'no emulation' image
-no-boot Boot image is not bootable
-boot-load-seg # Set load segment for boot image
-boot-load-size # Set numbers of load sectors
-boot-info-table Patch boot image with info table
-XA Generate XA directory attruibutes
-xa Generate rationalized XA directory attruibutes
-z, -transparent-compression
Enable transparent compression of files
-hfs-type TYPE Set HFS default TYPE
-hfs-creator CREATOR Set HFS default CREATOR
-g, -apple Add Apple ISO9660 extensions
-h, -hfs Create ISO9660/HFS hybrid
-map MAPPING_FILE Map file extensions to HFS TYPE/CREATOR
-H MAPPING_FILE, -map MAPPING_FILE
Map file extensions to HFS TYPE/CREATOR
-magic FILE Magic file for HFS TYPE/CREATOR
-probe Probe all files for Apple/Unix file types
-mac-name Use Macintosh name for ISO9660/Joliet/RockRidge file name
-no-mac-files Do not look for Unix/Mac files (depreciated)
-boot-hfs-file FILE Set HFS boot image name
-part Generate HFS partition table
-cluster-size SIZE Cluster size for PC Exchange Macintosh files
-auto FILE Set HFS AutoStart file name
-no-desktop Do not create the HFS (empty) Desktop files
-hide-hfs GLOBFILE Hide HFS file
-hide-hfs-list FILE List of HFS files to hide
-hfs-volid HFS_VOLID Volume name for the HFS partition
-icon-position Keep HFS icon position
-root-info FILE finderinfo for root folder
-input-hfs-charset CHARSET Local input charset for HFS file name conversion
-output-hfs-charset CHARSET Output charset for HFS file name conversion
-hfs-unlock Leave HFS Volume unlocked
-hfs-bless FOLDER_NAME Name of Folder to be blessed
-hfs-parms PARAMETERS Comma separated list of HFS parameters
-prep-boot FILE PReP boot image file -- up to 4 are allowed
-chrp-boot Add CHRP boot header
--cap Look for AUFS CAP Macintosh files
--netatalk Look for NETATALK Macintosh files
--double Look for AppleDouble Macintosh files
--ethershare Look for Helios EtherShare Macintosh files
--exchange Look for PC Exchange Macintosh files
--sgi Look for SGI Macintosh files
--macbin Look for MacBinary Macintosh files
--single Look for AppleSingle Macintosh files
--ushare Look for IPT UShare Macintosh files
--xinet Look for XINET Macintosh files
--dave Look for DAVE Macintosh files
--sfm Look for SFM Macintosh files
--osx-double Look for MacOS X AppleDouble Macintosh files
--osx-hfs Look for MacOS X HFS Macintosh files
Report problems to debburn-devel@lists.alioth.debian.org.
Concepts RAID
Les solutions RAID ou Redundant Array of Independent Disks ou encore Redundant Array of Inexpensive Disks permettent la combinaison de plusieurs disques de façon à ce que ceux-ci soient vu comme un seul disque logique.
Les solutions RAID sont issues du travail fourni par l'université de Berkeley en Californie sur un projet de tolérances de pannes. Les systèmes RAID offre maintenant plusieurs avantages :
- Addition des capacités,
- Amélioration des performances,
- Apporter la tolérance de panne.
Deux concepts sont fondamentaux à la compréhension des solutions RAID.
Disques en miroir
La technique des disques en miroir consiste à dupliquer l'écriture des données sur plusieurs disques. Le miroir peut être géré par un logiciel ou par du matériel.
Bandes de données
La technique des bandes de données, autrement appelée data striping consiste à couper les données à enregistrer en segments séquentiels et contigus pour les enregistrer sur plusieurs disques physiques. L'ensemble des segments constitue alors un disque logique ou striped disk. Cette technique peut être améliorée en déposant une bande de parité, calculée à partir des données des autres bandes, afin de pouvoir reconstituer une bande de données défaillante.
Types de RAID
RAID 0 - Concaténation
Création de volume par récupération de l'espace libre sur un ou plusieurs disques. Le principe de la concaténation est la création d'un volume à bandes où chaque bande est une tranche.
Avantages
- Récupération de l'espace disque.
Inconvénients
- Pas de protection des données,
- Pas d'augmentation des performances d'E/S.
RAID 0 - Striping
Création de volume sur plusieurs disques afin d'augmenter les performances d'E/S. Le principe du striping est la création d'un volume à bandes réparties sur plusieurs tranches. La taille de la bande doit être fonction des données à écrire sur le volume (16k, 32k, 64k, etc.) Cette taille est choisie à la création du volume.
Avantages
- Augmentation des performances d'E/S par écriture en parallèle sur les disques.
Inconvénients
- Pas de protection des données.
RAID 1 - Miroir
Création d'un volume où les disques sont en miroir. Quand les deux disques sont connectés à des contrôleurs de disques différents, on parle de duplexing :
Avantages
- Protection des données contre une défaillance d'un disque.
Inconvénients
- Coûteux à cause de l'augmentation du nombre de disques.
RAID 1+0 - Striping en Miroir
Le RAID 1+0 ou encore 0+1 est une technique qui réunit le RAID 0 et le RAID 1. On l'appelle aussi un RAID exotique:
Avantages
- Protection des données contre une défaillance d'un disque.
- Augmentation des performances d'E/S par écriture en parallèle sur les disques.
Inconvénients
- Coûteux à cause de l'augmentation du nombre de disques.
RAID 2 - Miroir avec Contrôle d'Erreurs
Le RAID 2 est une technique de miroir avec contrôle de correction d'erreurs (EEC). De nos jours cette technique est peu utilisée, ayant été remplacée par les RAID 3, 4 et 5.
RAID 3 et 4 - Striping avec Parité
Les RAID 3 et 4 sont des technologies avec bandes de parité distribuées sur un seul disque :
En RAID 3, la taille des segments n’est pas modifiable et est fixée à 512 octets (en RAID 3 : un segment = un secteur de disque dur = 512 octets).
En RAID 4, la taille des segments est variable et se modifie en temps réel. Cela implique que les informations de parité doivent être mise à jour à chaque écriture afin de vérifier si la taille des segments a été modifiée.
Avantages
- Protection des données contre une défaillance d'un disque.
Inconvénients
- Création d'un goulot d'étranglement des données à cause de l'écriture des données de parité sur un seul disque.
RAID 5 - Striping avec Parité Distribuée
Le RAID 5 est une technologie avec bandes de parité distribuées sur plusieurs disques :
Avantages
- Protection des données contre une défaillance d'un disque,
- Evite le goulot d'étranglement d'un seul disque de parité.
Inconvénients
- Lecture moins performante qu'avec RAID 3 et 4.
Au délà de RAID 5
Il existe aussi deux autres technologies RAID, toute deux issues de la technologie RAID 5 :
- RAID 6
- Disk Striping with Double Distributed Parity
- RAID TP
- Disk Striping with Triple Distributed Parity
RAID Logiciel sous RHEL/CentOS
Préparation du disque
Partitionnement
Suite à votre LAB de la leçon Gestion des Disques et le Swap, votre disque comporte 12 partitions :
[root@centos7 ~]# fdisk -l Disk /dev/sda: 21.5 GB, 21474836480 bytes, 41943040 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk label type: dos Disk identifier: 0x000c5a90 Device Boot Start End Blocks Id System /dev/sda1 * 2048 411647 204800 83 Linux /dev/sda2 411648 20891647 10240000 83 Linux /dev/sda3 20891648 25083903 2096128 82 Linux swap / Solaris /dev/sda4 25083904 41943039 8429568 5 Extended /dev/sda5 25085952 26109951 512000 fd Linux raid autodetect /dev/sda6 26112000 26521599 204800 8e Linux LVM /dev/sda7 26523648 27138047 307200 8e Linux LVM /dev/sda8 27140096 28164095 512000 fd Linux raid autodetect /dev/sda9 28166144 28985343 409600 8e Linux LVM /dev/sda10 28987392 30011391 512000 fd Linux raid autodetect /dev/sda11 30013440 31037439 512000 fd Linux raid autodetect /dev/sda12 31039488 31449087 204800 83 Linux
Mise en Place du RAID 5 Logiciel
Dans le cas de cet exemple les quatre partitions concernées par la mise en place d'un RAID 5 sont :
/dev/sda5 25085952 26109951 512000 fd Linux raid autodetect /dev/sda8 27140096 28164095 512000 fd Linux raid autodetect /dev/sda10 28987392 30011391 512000 fd Linux raid autodetect /dev/sda11 30013440 31037439 512000 fd Linux raid autodetect
La création d'une unité RAID avec la commande mdadm se fait grâce aux options passées en arguments à la commande :
mdadm --create <unité RAID> [options] <unités physiques>
Par exemple, saisissez la commande suivante :
[root@centos7 ~]# mdadm --create /dev/md1 --level=5 --raid-devices=3 /dev/sda5 /dev/sda8 /dev/sda11 mdadm: Defaulting to version 1.2 metadata mdadm: array /dev/md1 started.
Les options dans la ligne de commande sont :
| Option Courte | Option Longue | Description |
|---|---|---|
| -l | - -level | Le niveau RAID - linear, 0,1,2,4 ou 5 |
| -n | - -raid-devices=<nombre> | Le nombre de périphériques actifs dans le RAID |
Les autres options de la commande mdadm peuvent être visualisées grâce à la commande suivante :
[root@centos7 ~]# mdadm --help-options
Any parameter that does not start with '-' is treated as a device name
or, for --examine-bitmap, a file name.
The first such name is often the name of an md device. Subsequent
names are often names of component devices.
Some common options are:
--help -h : General help message or, after above option,
mode specific help message
--help-options : This help message
--version -V : Print version information for mdadm
--verbose -v : Be more verbose about what is happening
--quiet -q : Don't print un-necessary messages
--brief -b : Be less verbose, more brief
--export -Y : With --detail, --detail-platform or --examine use
key=value format for easy import into environment
--force -f : Override normal checks and be more forceful
--assemble -A : Assemble an array
--build -B : Build an array without metadata
--create -C : Create a new array
--detail -D : Display details of an array
--examine -E : Examine superblock on an array component
--examine-bitmap -X: Display the detail of a bitmap file
--examine-badblocks: Display list of known bad blocks on device
--monitor -F : monitor (follow) some arrays
--grow -G : resize/ reshape and array
--incremental -I : add/remove a single device to/from an array as appropriate
--query -Q : Display general information about how a
device relates to the md driver
--auto-detect : Start arrays auto-detected by the kernel
Les modes majeurs de la commande mdadm peuvent être visualisés grâce à la commande suivante :
[root@centos7 ~]# mdadm --help
mdadm is used for building, managing, and monitoring
Linux md devices (aka RAID arrays)
Usage: mdadm --create device options...
Create a new array from unused devices.
mdadm --assemble device options...
Assemble a previously created array.
mdadm --build device options...
Create or assemble an array without metadata.
mdadm --manage device options...
make changes to an existing array.
mdadm --misc options... devices
report on or modify various md related devices.
mdadm --grow options device
resize/reshape an active array
mdadm --incremental device
add/remove a device to/from an array as appropriate
mdadm --monitor options...
Monitor one or more array for significant changes.
mdadm device options...
Shorthand for --manage.
Any parameter that does not start with '-' is treated as a device name
or, for --examine-bitmap, a file name.
The first such name is often the name of an md device. Subsequent
names are often names of component devices.
For detailed help on the above major modes use --help after the mode
e.g.
mdadm --assemble --help
For general help on options use
mdadm --help-options
Dernièrement, chaque mode majeur dispose de son propre aide :
[root@centos7 ~]# mdadm --assemble --help
Usage: mdadm --assemble device options...
mdadm --assemble --scan options...
This usage assembles one or more raid arrays from pre-existing
components.
For each array, mdadm needs to know the md device, the identity of
the array, and a number of sub devices. These can be found in a number
of ways.
The md device is given on the command line, is found listed in the
config file, or can be deduced from the array identity.
The array identity is determined either from the --uuid, --name, or
--super-minor commandline arguments, from the config file,
or from the first component device on the command line.
The different combinations of these are as follows:
If the --scan option is not given, then only devices and identities
listed on the command line are considered.
The first device will be the array device, and the remainder will be
examined when looking for components.
If an explicit identity is given with --uuid or --super-minor, then
only devices with a superblock which matches that identity is considered,
otherwise every device listed is considered.
If the --scan option is given, and no devices are listed, then
every array listed in the config file is considered for assembly.
The identity of candidate devices are determined from the config file.
After these arrays are assembled, mdadm will look for other devices
that could form further arrays and tries to assemble them. This can
be disabled using the 'AUTO' option in the config file.
If the --scan option is given as well as one or more devices, then
Those devices are md devices that are to be assembled. Their identity
and components are determined from the config file.
If mdadm can not find all of the components for an array, it will assemble
it but not activate it unless --run or --scan is given. To preserve this
behaviour even with --scan, add --no-degraded. Note that "all of the
components" means as many as were present the last time the array was running
as recorded in the superblock. If the array was already degraded, and
the missing device is not a new problem, it will still be assembled. It
is only newly missing devices that cause the array not to be started.
Options that are valid with --assemble (-A) are:
--bitmap= : bitmap file to use with the array
--uuid= -u : uuid of array to assemble. Devices which don't
have this uuid are excluded
--super-minor= -m : minor number to look for in super-block when
choosing devices to use.
--name= -N : Array name to look for in super-block.
--config= -c : config file
--scan -s : scan config file for missing information
--run -R : Try to start the array even if not enough devices
for a full array are present
--force -f : Assemble the array even if some superblocks appear
: out-of-date. This involves modifying the superblocks.
--update= -U : Update superblock: try '-A --update=?' for option list.
--no-degraded : Assemble but do not start degraded arrays.
--readonly -o : Mark the array as read-only. No resync will start.
Constatez maintenant les informations concernant le RAID 5 créé :
[root@centos7 ~]# cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
md1 : active raid5 sda11[3] sda8[1] sda5[0]
1021952 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/3] [UUU]
unused devices: <none>
Grâce à la commande mdadm, il est possible d'obtenir d'avantage d'informations :
[root@centos7 ~]# mdadm --query /dev/md1 /dev/md1: 998.17MiB raid5 3 devices, 0 spares. Use mdadm --detail for more detail.
L'option - -detail produit le résultat suivant :
[root@centos7 ~]# mdadm --detail /dev/md1
/dev/md1:
Version : 1.2
Creation Time : Tue Aug 2 15:10:12 2016
Raid Level : raid5
Array Size : 1021952 (998.17 MiB 1046.48 MB)
Used Dev Size : 510976 (499.08 MiB 523.24 MB)
Raid Devices : 3
Total Devices : 3
Persistence : Superblock is persistent
Update Time : Tue Aug 2 15:10:17 2016
State : clean
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : centos7.fenestros.loc:1 (local to host centos7.fenestros.loc)
UUID : fd8bac53:1457a4f4:30feab84:e0f9d8e0
Events : 18
Number Major Minor RaidDevice State
0 8 5 0 active sync /dev/sda5
1 8 8 1 active sync /dev/sda8
3 8 11 2 active sync /dev/sda11
Notez la ligne Persistence : Superblock is persistent. En effet, cette implémentation de RAID inscrit les caractéristiques du volume dans un super bloc persistant en début de chaque unité de type bloc dans le volume.
Recherchez la signification des termes Layout, Chunk size, Major et Minor.
Cependant, il necéssaire de renseigner le fichier /etc/mdadm.conf afin que le RAID soit contruit à chaque démarrage :
[root@centos7 ~]# echo 'DEVICES /dev/sda5 /dev/sda8 /dev/sda11' > /etc/mdadm.conf [root@centos7 ~]# mdadm --detail --scan >> /etc/mdadm.conf [root@centos7 ~]# cat /etc/mdadm.conf DEVICES /dev/sda5 /dev/sda8 /dev/sda11 ARRAY /dev/md1 metadata=1.2 name=centos7.fenestros.loc:1 UUID=fd8bac53:1457a4f4:30feab84:e0f9d8e0
Chaque unité peut être examinée individuellement :
[root@centos7 ~]# mdadm --examine /dev/sda5
/dev/sda5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : fd8bac53:1457a4f4:30feab84:e0f9d8e0
Name : centos7.fenestros.loc:1 (local to host centos7.fenestros.loc)
Creation Time : Tue Aug 2 15:10:12 2016
Raid Level : raid5
Raid Devices : 3
Avail Dev Size : 1021952 (499.08 MiB 523.24 MB)
Array Size : 1021952 (998.17 MiB 1046.48 MB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Unused Space : before=1960 sectors, after=0 sectors
State : clean
Device UUID : 4569e15e:20201bce:365776f2:75aed23f
Update Time : Tue Aug 2 15:10:17 2016
Bad Block Log : 512 entries available at offset 72 sectors
Checksum : 4c9948d0 - correct
Events : 18
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 0
Array State : AAA ('A' == active, '.' == missing, 'R' == replacing)
A ce stade il est intéressant de noter comment réagir lors d'une défaillance d'un disque. Dans notre cas nous allons indiquer au système que la partition /dev/sda5 est devenue défaillante :
[root@centos7 ~]# mdadm --manage --set-faulty /dev/md1 /dev/sda5 mdadm: set /dev/sda5 faulty in /dev/md1
L'utilisation de la ligne de commande suivante nous confirme le statut de /dev/sda5 :
[root@centos7 ~]# mdadm --detail /dev/md1
/dev/md1:
Version : 1.2
Creation Time : Tue Aug 2 15:10:12 2016
Raid Level : raid5
Array Size : 1021952 (998.17 MiB 1046.48 MB)
Used Dev Size : 510976 (499.08 MiB 523.24 MB)
Raid Devices : 3
Total Devices : 3
Persistence : Superblock is persistent
Update Time : Tue Aug 2 15:14:59 2016
State : clean, degraded
Active Devices : 2
Working Devices : 2
Failed Devices : 1
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : centos7.fenestros.loc:1 (local to host centos7.fenestros.loc)
UUID : fd8bac53:1457a4f4:30feab84:e0f9d8e0
Events : 20
Number Major Minor RaidDevice State
0 0 0 0 removed
1 8 8 1 active sync /dev/sda8
3 8 11 2 active sync /dev/sda11
0 8 5 - faulty /dev/sda5
Il est maintenant nécessaire de supprimer /dev/sda5 de notre RAID 5 :
[root@centos7 ~]# mdadm --manage --remove /dev/md1 /dev/sda5 mdadm: hot removed /dev/sda5 from /dev/md1
A l'examen de notre RAID, on constate que /dev/sda5 a été supprimé :
[root@centos7 ~]# mdadm --detail /dev/md1
/dev/md1:
Version : 1.2
Creation Time : Tue Aug 2 15:10:12 2016
Raid Level : raid5
Array Size : 1021952 (998.17 MiB 1046.48 MB)
Used Dev Size : 510976 (499.08 MiB 523.24 MB)
Raid Devices : 3
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Tue Aug 2 15:16:41 2016
State : clean, degraded
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : centos7.fenestros.loc:1 (local to host centos7.fenestros.loc)
UUID : fd8bac53:1457a4f4:30feab84:e0f9d8e0
Events : 21
Number Major Minor RaidDevice State
0 0 0 0 removed
1 8 8 1 active sync /dev/sda8
3 8 11 2 active sync /dev/sda11
Constatez maintenant l'existance de votre RAID :
[root@centos7 ~]# cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
md1 : active raid5 sda11[3] sda8[1]
1021952 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/2] [_UU]
unused devices: <none>
Notez que le RAID a été démarré avec 2 unités au lieu de trois.
Pour ajouter un autre disque à notre RAID afin de remplacer /dev/sda5 il convient d'utiliser l'option –add :
[root@centos7 ~]# mdadm --manage --add /dev/md1 /dev/sda10 mdadm: added /dev/sda10
L'exemen du RAID indique que /dev/sda10 a été ajouté en tant que spare et à l'issu de quelques minutes le RAID 5 a été reconstruite :
[root@centos7 ~]# mdadm --detail /dev/md1
/dev/md1:
Version : 1.2
Creation Time : Tue Aug 2 15:10:12 2016
Raid Level : raid5
Array Size : 1021952 (998.17 MiB 1046.48 MB)
Used Dev Size : 510976 (499.08 MiB 523.24 MB)
Raid Devices : 3
Total Devices : 3
Persistence : Superblock is persistent
Update Time : Tue Aug 2 15:19:06 2016
State : clean
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : centos7.fenestros.loc:1 (local to host centos7.fenestros.loc)
UUID : fd8bac53:1457a4f4:30feab84:e0f9d8e0
Events : 40
Number Major Minor RaidDevice State
4 8 10 0 active sync /dev/sda10
1 8 8 1 active sync /dev/sda8
3 8 11 2 active sync /dev/sda11
Naturellement, il necéssaire de renseigner le fichier /etc/mdadm.conf du changement afin que le RAID soit contruit à chaque démarrage :
[root@centos7 ~]# echo 'DEVICES /dev/sda10 /dev/sda8 /dev/sda11' > /etc/mdadm.conf [root@centos7 ~]# mdadm --detail --scan >> /etc/mdadm.conf [root@centos7 ~]# cat /etc/mdadm.conf DEVICES /dev/sda10 /dev/sda8 /dev/sda11 ARRAY /dev/md1 metadata=1.2 name=centos7.fenestros.loc:1 UUID=fd8bac53:1457a4f4:30feab84:e0f9d8e0
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