Version : 2021.01

Updated :

LCE504 - Managing Disks and Filesystems

Contents

LCE504 - Managing Disks and Filesystems

Contents

Peripherals

Partitions

Partitioning

LAB #1 - Partioning your Disk with the fdisk Command

LAB #2 - Modifier les Drapeaux des Partitions avec fdisk

Logical Volume Manager (LVM)

LAB #3 - Linear Logical Volumes

Physical Volumes (PV)

Volume Groups (VG) and Physical Extents (PE)

Logical Volumes (LV)

LAB #4 - Grow a Volume

LAB #5 - Snapshots

LAB #6 - Deleting Volumes

LAB #7 - Mirrored Volumes

LAB #8 - Changing LVM Attributes

LAB #9 - Striped Volumes

LAB #10 - Managing Meta-data

Journaled Filesystems

Ext3

Managing Ext3

LAB #11 - Converting Ext3 to Ext2

LAB #12 - Converting Ext2 to Ext3

LAB #13 - Using another PArtition for the Journal

LAB #14 - Changing the File System Check interval on an ext3 Filesystem

Ext4

LAB #15 - Creating an Ext4 Filesystem

LAB #16 - Adding a Label to an Ext4 Filesystem

LAB #17 - Converting Ext3 to Ext4

XFS

LAB #18 - Creating an XFS Filesystem

LAB #19 - Adding a Label to an XFS Filesystem

Peripherals

hd[a-d]

IDE and ATAPI

sd[a-z]

SCSI and SATA

mmcblk[0-7]

SD/MMC

scd[0-7]

SCSI CDRoms

xd[a-d]

IBM XT disks

fd[0-7]

Diskettes

st[0-7]

SCSI/SATA streamers that can rewind

nst[0-7]

SCSI/SATA streamers that cannot rewind

ht[0-7]

PATA streamers that can rewind

nht[0-7]

PATA streamers that cannot rewind

rmt8, rmt16, tape-d, tape-reset

QIC-80

ram[0-15]

Virtual disks

Périphériques loop

Used to access a filesystem in a file

md[x]

MetaDevice - Software RAID

vg[x]

Volume Group

lv[x]

Logical Volume

Partitions

The number of partitions is limited :

IDE,

Up to 63,

SCSI,

Up to 15,

Disks using the API libata,

Up to 15.

Partitioning

LAB #1 - Partioning your Disk with the fdisk Command

[root@centos8 ~]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.32.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0xb0dacb39.
Command (m for help):

Command (m for help): m
Help:
DOS (MBR)
a toggle a bootable flag
b edit nested BSD disklabel
c toggle the dos compatibility flag
Generic
d delete a partition
F list free unpartitioned space
l list known partition types
n add a new partition
p print the partition table
t change a partition type
v verify the partition table
i print information about a partition
Misc
m print this menu
u change display/entry units
x extra functionality (experts only)
Script
I load disk layout from sfdisk script file
O dump disk layout to sfdisk script file
Save & Exit
w write table to disk and exit
q quit without saving changes
Create a new label
g create a new empty GPT partition table
G create a new empty SGI (IRIX) partition table
o create a new empty DOS partition table
s create a new empty Sun partition table
Command (m for help):

Create the following partitions:

Partition	Type	Size
/dev/sdb1	Primary	100 MB
/dev/sdb2	Primary	100 MB
/dev/sdb3	Primary	100 MB
/dev/sdb4	Extended	From the first available to the last available sectors
/dev/sdb5	Logical	500 MB
/dev/sdb6	Logical	200 MB
/dev/sdb7	Logical	300 MB
/dev/sda8	Logical	500 MB
/dev/sdb9	Logical	400 MB
/dev/sdb10	Logical	500 MB
/dev/sdb11	Logical	500 MB
/dev/sdb12	Logical	200 MB

Command (m for help): n
Partition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p):
Using default response p.
Partition number (1-4, default 1):
First sector (2048-8388607, default 2048):
Last sector, +sectors or +size{K,M,G,T,P} (2048-8388607, default 8388607): +100M
Created a new partition 1 of type 'Linux' and of size 100 MiB.
Command (m for help): n
Partition type
p primary (1 primary, 0 extended, 3 free)
e extended (container for logical partitions)
Select (default p):
Using default response p.
Partition number (2-4, default 2):
First sector (206848-8388607, default 206848):
Last sector, +sectors or +size{K,M,G,T,P} (206848-8388607, default 8388607): +100M
Created a new partition 2 of type 'Linux' and of size 100 MiB.
Command (m for help): n
Partition type
p primary (2 primary, 0 extended, 2 free)
e extended (container for logical partitions)
Select (default p):
Using default response p.
Partition number (3,4, default 3):
First sector (411648-8388607, default 411648):
Last sector, +sectors or +size{K,M,G,T,P} (411648-8388607, default 8388607): +100M
Created a new partition 3 of type 'Linux' and of size 100 MiB.
Command (m for help):

Command (m for help): n
Partition type
p primary (3 primary, 0 extended, 1 free)
e extended (container for logical partitions)
Select (default e): e
Selected partition 4
First sector (616448-8388607, default 616448):
Last sector, +sectors or +size{K,M,G,T,P} (616448-8388607, default 8388607):
Created a new partition 4 of type 'Extended' and of size 3.7 GiB.
Command (m for help):

Command (m for help): n
All primary partitions are in use.
Adding logical partition 5
First sector (618496-8388607, default 618496):
Last sector, +sectors or +size{K,M,G,T,P} (618496-8388607, default 8388607): +500M
Created a new partition 5 of type 'Linux' and of size 500 MiB.
Command (m for help): n
All primary partitions are in use.
Adding logical partition 6
First sector (1644544-8388607, default 1644544):
Last sector, +sectors or +size{K,M,G,T,P} (1644544-8388607, default 8388607): +200M
Created a new partition 6 of type 'Linux' and of size 200 MiB.
Command (m for help): n
All primary partitions are in use.
Adding logical partition 7
First sector (2056192-8388607, default 2056192):
Last sector, +sectors or +size{K,M,G,T,P} (2056192-8388607, default 8388607): +300M
Created a new partition 7 of type 'Linux' and of size 300 MiB.
Command (m for help): n
All primary partitions are in use.
Adding logical partition 8
First sector (2672640-8388607, default 2672640):
Last sector, +sectors or +size{K,M,G,T,P} (2672640-8388607, default 8388607): +500M
Created a new partition 8 of type 'Linux' and of size 500 MiB.
Command (m for help): n
All primary partitions are in use.
Adding logical partition 9
First sector (3698688-8388607, default 3698688):
Last sector, +sectors or +size{K,M,G,T,P} (3698688-8388607, default 8388607): +400M
Created a new partition 9 of type 'Linux' and of size 400 MiB.
Command (m for help): n
All primary partitions are in use.
Adding logical partition 10
First sector (4519936-8388607, default 4519936):
Last sector, +sectors or +size{K,M,G,T,P} (4519936-8388607, default 8388607): +500M
Created a new partition 10 of type 'Linux' and of size 500 MiB.
Command (m for help): n
All primary partitions are in use.
Adding logical partition 11
First sector (5545984-8388607, default 5545984):
Last sector, +sectors or +size{K,M,G,T,P} (5545984-8388607, default 8388607): +500M
Created a new partition 11 of type 'Linux' and of size 500 MiB.
Command (m for help): n
All primary partitions are in use.
Adding logical partition 12
First sector (6572032-8388607, default 6572032):
Last sector, +sectors or +size{K,M,G,T,P} (6572032-8388607, default 8388607): +200M
Created a new partition 12 of type 'Linux' and of size 200 MiB.
Command (m for help):

Command (m for help): p
Disk /dev/sdb: 4 GiB, 4294967296 bytes, 8388608 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
Disklabel type: dos
Disk identifier: 0xb0dacb39
Device Boot Start End Sectors Size Id Type
/dev/sdb1 2048 206847 204800 100M 83 Linux
/dev/sdb2 206848 411647 204800 100M 83 Linux
/dev/sdb3 411648 616447 204800 100M 83 Linux
/dev/sdb4 616448 8388607 7772160 3.7G 5 Extended
/dev/sdb5 618496 1642495 1024000 500M 83 Linux
/dev/sdb6 1644544 2054143 409600 200M 83 Linux
/dev/sdb7 2056192 2670591 614400 300M 83 Linux
/dev/sdb8 2672640 3696639 1024000 500M 83 Linux
/dev/sdb9 3698688 4517887 819200 400M 83 Linux
/dev/sdb10 4519936 5543935 1024000 500M 83 Linux
/dev/sdb11 5545984 6569983 1024000 500M 83 Linux
/dev/sdb12 6572032 6981631 409600 200M 83 Linux
Command (m for help):

Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.
[root@centos8 ~]# partprobe
[root@centos8 ~]#

[root@centos8 ~]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.32.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): p
Disk /dev/sdb: 4 GiB, 4294967296 bytes, 8388608 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
Disklabel type: dos
Disk identifier: 0xb0dacb39
Device Boot Start End Sectors Size Id Type
/dev/sdb1 2048 206847 204800 100M 83 Linux
/dev/sdb2 206848 411647 204800 100M 83 Linux
/dev/sdb3 411648 616447 204800 100M 83 Linux
/dev/sdb4 616448 8388607 7772160 3.7G 5 Extended
/dev/sdb5 618496 1642495 1024000 500M 83 Linux
/dev/sdb6 1644544 2054143 409600 200M 83 Linux
/dev/sdb7 2056192 2670591 614400 300M 83 Linux
/dev/sdb8 2672640 3696639 1024000 500M 83 Linux
/dev/sdb9 3698688 4517887 819200 400M 83 Linux
/dev/sdb10 4519936 5543935 1024000 500M 83 Linux
/dev/sdb11 5545984 6569983 1024000 500M 83 Linux
/dev/sdb12 6572032 6981631 409600 200M 83 Linux
Command (m for help):

Command (m for help): d
Partition number (1-12, default 12): 12
Partition 12 has been deleted.
Command (m for help): p
Disk /dev/sdb: 4 GiB, 4294967296 bytes, 8388608 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
Disklabel type: dos
Disk identifier: 0xb0dacb39
Device Boot Start End Sectors Size Id Type
/dev/sdb1 2048 206847 204800 100M 83 Linux
/dev/sdb2 206848 411647 204800 100M 83 Linux
/dev/sdb3 411648 616447 204800 100M 83 Linux
/dev/sdb4 616448 8388607 7772160 3.7G 5 Extended
/dev/sdb5 618496 1642495 1024000 500M 83 Linux
/dev/sdb6 1644544 2054143 409600 200M 83 Linux
/dev/sdb7 2056192 2670591 614400 300M 83 Linux
/dev/sdb8 2672640 3696639 1024000 500M 83 Linux
/dev/sdb9 3698688 4517887 819200 400M 83 Linux
/dev/sdb10 4519936 5543935 1024000 500M 83 Linux
/dev/sdb11 5545984 6569983 1024000 500M 83 Linux
Command (m for help):

Command (m for help): q
[root@centos8 ~]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.32.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): p
Disk /dev/sdb: 4 GiB, 4294967296 bytes, 8388608 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
Disklabel type: dos
Disk identifier: 0xb0dacb39
Device Boot Start End Sectors Size Id Type
/dev/sdb1 2048 206847 204800 100M 83 Linux
/dev/sdb2 206848 411647 204800 100M 83 Linux
/dev/sdb3 411648 616447 204800 100M 83 Linux
/dev/sdb4 616448 8388607 7772160 3.7G 5 Extended
/dev/sdb5 618496 1642495 1024000 500M 83 Linux
/dev/sdb6 1644544 2054143 409600 200M 83 Linux
/dev/sdb7 2056192 2670591 614400 300M 83 Linux
/dev/sdb8 2672640 3696639 1024000 500M 83 Linux
/dev/sdb9 3698688 4517887 819200 400M 83 Linux
/dev/sdb10 4519936 5543935 1024000 500M 83 Linux
/dev/sdb11 5545984 6569983 1024000 500M 83 Linux
/dev/sdb12 6572032 6981631 409600 200M 83 Linux
Command (m for help):

LAB #2 - Modifier les Drapeaux des Partitions avec fdisk

Size	Type
500 MB	RAID (fd)
200 MB	Linux LVM (8e)
300 MB	Linux LVM (8e)
500 MB	RAID (fd)
400 MB	Linux LVM (8e)
500 MB	RAID (fd)
500 MB	RAID (fd)
200 MB	Do not change

Command (m for help): t
Partition number (1-12, default 12): 5
Hex code (type L to list all codes): fd
Changed type of partition 'Linux' to 'Linux raid autodetect'.
Command (m for help): t
Partition number (1-12, default 12): 6
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'.
Command (m for help): t
Partition number (1-12, default 12): 7
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'.
Command (m for help): t
Partition number (1-12, default 12): 8
Hex code (type L to list all codes): fd
Changed type of partition 'Linux' to 'Linux raid autodetect'.
Command (m for help): t
Partition number (1-12, default 12): 9
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'.
Command (m for help): t
Partition number (1-12, default 12): 10
Hex code (type L to list all codes): fd
Changed type of partition 'Linux' to 'Linux raid autodetect'.
Command (m for help): t
Partition number (1-12, default 12): 11
Hex code (type L to list all codes): fd
Changed type of partition 'Linux' to 'Linux raid autodetect'.

Command (m for help): p
Disk /dev/sdb: 4 GiB, 4294967296 bytes, 8388608 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
Disklabel type: dos
Disk identifier: 0xb0dacb39
Device Boot Start End Sectors Size Id Type
/dev/sdb1 2048 206847 204800 100M 83 Linux
/dev/sdb2 206848 411647 204800 100M 83 Linux
/dev/sdb3 411648 616447 204800 100M 83 Linux
/dev/sdb4 616448 8388607 7772160 3.7G 5 Extended
/dev/sdb5 618496 1642495 1024000 500M fd Linux raid autodetect
/dev/sdb6 1644544 2054143 409600 200M 8e Linux LVM
/dev/sdb7 2056192 2670591 614400 300M 8e Linux LVM
/dev/sdb8 2672640 3696639 1024000 500M fd Linux raid autodetect
/dev/sdb9 3698688 4517887 819200 400M 8e Linux LVM
/dev/sdb10 4519936 5543935 1024000 500M fd Linux raid autodetect
/dev/sdb11 5545984 6569983 1024000 500M fd Linux raid autodetect
/dev/sdb12 6572032 6981631 409600 200M 83 Linux
Command (m for help):

Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.
[root@centos8 ~]# partprobe

Command Line Switches

The command line switches of this command are:

[root@centos8 ~]# fdisk --help
Usage:
fdisk [options] <disk> change partition table
fdisk [options] -l [<disk>] list partition table(s)
Display or manipulate a disk partition table.
Options:
-b, --sector-size <size> physical and logical sector size
-B, --protect-boot don't erase bootbits when creating a new label
-c, --compatibility[=<mode>] mode is 'dos' or 'nondos' (default)
-L, --color[=<when>] colorize output (auto, always or never)
colors are enabled by default
-l, --list display partitions and exit
-o, --output <list> output columns
-t, --type <type> recognize specified partition table type only
-u, --units[=<unit>] display units: 'cylinders' or 'sectors' (default)
-s, --getsz display device size in 512-byte sectors [DEPRECATED]
--bytes print SIZE in bytes rather than in human readable format
-w, --wipe <mode> wipe signatures (auto, always or never)
-W, --wipe-partitions <mode> wipe signatures from new partitions (auto, always or never)
-C, --cylinders <number> specify the number of cylinders
-H, --heads <number> specify the number of heads
-S, --sectors <number> specify the number of sectors per track
-h, --help display this help
-V, --version display version
Available output columns:
gpt: Device Start End Sectors Size Type Type-UUID Attrs Name UUID
dos: Device Start End Sectors Cylinders Size Type Id Attrs Boot End-C/H/S Start-C/H/S
bsd: Slice Start End Sectors Cylinders Size Type Bsize Cpg Fsize
sgi: Device Start End Sectors Cylinders Size Type Id Attrs
sun: Device Start End Sectors Cylinders Size Type Id Flags
For more details see fdisk(8).

Logical Volume Manager (LVM)

LAB #3 - Linear Logical Volumes

/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

[root@centos8 ~]# vgscan
Found volume group "cl_centos8" using metadata type lvm2

The command line switches of this command are:

[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)

[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.

The command line switches of this command are:

[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.)

[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

The command line switches of this command are:

[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 Groups (VG) and Physical Extents (PE)

[root@centos8 ~]# vgcreate -s 8M vg0 /dev/sdb6 /dev/sdb7 /dev/sdb9
Volume group "vg0" successfully created

The command line switches of this command are:

[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.

[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

The command line switches of this command are:

[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)

[root@centos8 ~]# lvcreate -L 350 -n lv0 vg0
Rounding up size to full physical extent 352.00 MiB
Logical volume "lv0" created.

Important - Note that the LV size is a multiple of the PE size.

The command line switches of this command are:

[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.

[root@centos8 ~]# mkdir /mnt/lvm

[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

[root@centos8 ~]# mount -t ext3 /dev/vg0/lv0 /mnt/lvm

[root@centos8 ~]# cp -a /home /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

[root@centos8 ~]# df -h /mnt/lvm
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg0-lv0 333M 17M 314M 1% /mnt/lvm

LAB #4 - Growing a Volume

[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.

The command line switches of this command are:

[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.

[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.

[root@centos8 ~]# df -h /mnt/lvm
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg0-lv0 434M 17M 395M 5% /mnt/lvm

LAB #5 - Snapshots

[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

[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.

[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 - Note that the snapshot is created in the same VG as the original LV.

The command line switches of this command are:

[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.

[root@centos8 ~]# mkdir /mnt/testsnap

[root@centos8 ~]# mount /dev/vg0/testsnap /mnt/testsnap

[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

[root@centos8 ~]# rm /mnt/lvm/10M
rm: remove regular file '/mnt/lvm/10M'? y

[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

To do - Restore the 10M file.

LAB #6 - Deleting Volumes

[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

The command line switches of this command are:

[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

[root@centos8 ~]# vgremove vg0
Volume group "vg0" successfully removed

The command line switches of this command are:

[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.

[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.

The command line switches of this command are:

[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 - Mirrored Volumes

[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

[root@centos8 ~]# lvcreate -m 1 -L 100M -n lv1 vg0
Rounding up size to full physical extent 104.00 MiB
Logical volume "lv1" created.

[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

[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

[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.

[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.

[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.

The command line switches of this command are:

[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 - Changing LVM Attributes

[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

See this page .

[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

See this page.

[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

See this page.

[root@centos8 ~]# lvchange -a n /dev/vg0/lv1

[root@centos8 ~]# lvchange -a y /dev/vg0/lv1

The command line switches of this command are:

[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 - Striped Volumes

-i - number of stripes,

-I - size of stripe in KB.

[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.

[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

[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)

Journaled Filrsystems

Ext3

Managing Ext3

[root@centos8 ~]# fdisk -l
Disk /dev/sdb: 4 GiB, 4294967296 bytes, 8388608 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
Disklabel type: dos
Disk identifier: 0xb0dacb39
Device Boot Start End Sectors Size Id Type
/dev/sdb1 2048 206847 204800 100M 83 Linux
/dev/sdb2 206848 411647 204800 100M 83 Linux
/dev/sdb3 411648 616447 204800 100M 83 Linux
/dev/sdb4 616448 8388607 7772160 3.7G 5 Extended
/dev/sdb5 618496 1642495 1024000 500M fd Linux raid autodetect
/dev/sdb6 1644544 2054143 409600 200M 8e Linux LVM
/dev/sdb7 2056192 2670591 614400 300M 8e Linux LVM
/dev/sdb8 2672640 3696639 1024000 500M fd Linux raid autodetect
/dev/sdb9 3698688 4517887 819200 400M 8e Linux LVM
/dev/sdb10 4519936 5543935 1024000 500M fd Linux raid autodetect
/dev/sdb11 5545984 6569983 1024000 500M fd Linux raid autodetect
/dev/sdb12 6572032 6981631 409600 200M 83 Linux
Disk /dev/sda: 20 GiB, 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
Disklabel type: dos
Disk identifier: 0x70b17285
Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 616447 614400 300M 83 Linux
/dev/sda2 616448 4712447 4096000 2G 82 Linux swap / Solaris
/dev/sda3 4712448 35432447 30720000 14.7G 83 Linux
Disk /dev/mapper/vg0-lv1: 104 MiB, 109051904 bytes, 212992 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 /dev/mapper/vg0-lv2: 112 MiB, 117440512 bytes, 229376 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 65536 bytes / 131072 bytes

Créez un filesystem Ext3 sur /dev/sdb12 en utilisant la commande mke2fs -j :

[root@centos8 ~]# mke2fs -j /dev/sdb12
mke2fs 1.45.6 (20-Mar-2020)
Creating filesystem with 204800 1k blocks and 51200 inodes
Filesystem UUID: a2515f45-a32a-4e87-b7e6-170448f3f803
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729
Allocating group tables: done
Writing inode tables: done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done

The command line switches of this command are:

[root@centos8 ~]# mke2fs --help
mke2fs: invalid option -- '-'
Usage: mke2fs [-c|-l filename] [-b block-size] [-C cluster-size]
[-i bytes-per-inode] [-I inode-size] [-J journal-options]
[-G flex-group-size] [-N number-of-inodes] [-d root-directory]
[-m reserved-blocks-percentage] [-o creator-os]
[-g blocks-per-group] [-L volume-label] [-M last-mounted-directory]
[-O feature[,...]] [-r fs-revision] [-E extended-option[,...]]
[-t fs-type] [-T usage-type ] [-U UUID] [-e errors_behavior][-z undo_file]
[-jnqvDFSV] device [blocks-count]

LAB #11 - Converting Ext3 to Ext2

[root@centos8 ~]# dumpe2fs -h /dev/sdb12
dumpe2fs 1.45.6 (20-Mar-2020)
Filesystem volume name: <none>
Last mounted on: <not available>
Filesystem UUID: a2515f45-a32a-4e87-b7e6-170448f3f803
Filesystem magic number: 0xEF53
Filesystem revision #: 1 (dynamic)
Filesystem features: has_journal ext_attr resize_inode dir_index filetype sparse_super large_file
Filesystem flags: signed_directory_hash
Default mount options: user_xattr acl
Filesystem state: clean
Errors behavior: Continue
Filesystem OS type: Linux
Inode count: 51200
Block count: 204800
Reserved block count: 10240
Free blocks: 192674
Free inodes: 51189
First block: 1
Block size: 1024
Fragment size: 1024
Reserved GDT blocks: 256
Blocks per group: 8192
Fragments per group: 8192
Inodes per group: 2048
Inode blocks per group: 256
Filesystem created: Wed Jun 2 07:55:24 2021
Last mount time: n/a
Last write time: Wed Jun 2 07:55:24 2021
Mount count: 0
Maximum mount count: -1
Last checked: Wed Jun 2 07:55:24 2021
Check interval: 0 (<none>)
Reserved blocks uid: 0 (user root)
Reserved blocks gid: 0 (group root)
First inode: 11
Inode size:	128
Journal inode: 8
Default directory hash: half_md4
Directory Hash Seed: faee0b81-0538-4c06-8d86-468bc0c760ac
Journal backup: inode blocks
Journal features: (none)
Journal size: 4096k
Journal length: 4096
Journal sequence: 0x00000001
Journal start: 0

Important : The Filesystem features: has_journal … shows that Ext3 is on the partition.

The command line switches of this command are:

[root@centos8 ~]# dumpe2fs --help
dumpe2fs 1.45.6 (20-Mar-2020)
dumpe2fs: invalid option -- '-'
Usage: dumpe2fs [-bfghimxV] [-o superblock=<num>] [-o blocksize=<num>] device

[root@centos8 ~]# tune2fs -O ^has_journal /dev/sdb12
tune2fs 1.45.6 (20-Mar-2020)

The command line switches of this command are:

[root@centos8 ~]# tune2fs --help
tune2fs 1.45.6 (20-Mar-2020)
tune2fs: invalid option -- '-'
Usage: tune2fs [-c max_mounts_count] [-e errors_behavior] [-f] [-g group]
[-i interval[d|m|w]] [-j] [-J journal_options] [-l]
[-m reserved_blocks_percent] [-o [^]mount_options[,...]]
[-r reserved_blocks_count] [-u user] [-C mount_count]
[-L volume_label] [-M last_mounted_dir]
[-O [^]feature[,...]] [-Q quota_options]
[-E extended-option[,...]] [-T last_check_time] [-U UUID]
[-I new_inode_size] [-z undo_file] device

[root@centos8 ~]# dumpe2fs -h /dev/sdb12
dumpe2fs 1.45.6 (20-Mar-2020)
Filesystem volume name: <none>
Last mounted on: <not available>
Filesystem UUID: a2515f45-a32a-4e87-b7e6-170448f3f803
Filesystem magic number: 0xEF53
Filesystem revision #: 1 (dynamic)
Filesystem features: ext_attr resize_inode dir_index filetype sparse_super large_file
Filesystem flags: signed_directory_hash
Default mount options: user_xattr acl
Filesystem state: clean
Errors behavior: Continue
Filesystem OS type: Linux
Inode count: 51200
Block count: 204800
Reserved block count: 10240
Free blocks: 196787
Free inodes: 51189
First block: 1
Block size: 1024
Fragment size: 1024
Reserved GDT blocks: 256
Blocks per group: 8192
Fragments per group: 8192
Inodes per group: 2048
Inode blocks per group: 256
Filesystem created: Wed Jun 2 07:55:24 2021
Last mount time: n/a
Last write time: Wed Jun 2 07:59:01 2021
Mount count: 0
Maximum mount count: -1
Last checked: Wed Jun 2 07:55:24 2021
Check interval: 0 (<none>)
Reserved blocks uid: 0 (user root)
Reserved blocks gid: 0 (group root)
First inode: 11
Inode size:	128
Default directory hash: half_md4
Directory Hash Seed: faee0b81-0538-4c06-8d86-468bc0c760ac
Journal backup: inode blocks

[root@centos8 ~]# fsck /dev/sdb12
fsck from util-linux 2.32.1
e2fsck 1.45.6 (20-Mar-2020)
/dev/sdb12: clean, 11/51200 files, 8013/204800 blocks

[root@centos8 ~]# mkdir /mnt/sdb12

[root@centos8 ~]# mount -t ext3 /dev/sdb12 /mnt/sdb12
mount: /mnt/sdb12: wrong fs type, bad option, bad superblock on /dev/sdb12, missing codepage or helper program, or other error.

[root@centos8 ~]# mount -t ext2 /dev/sdb12 /mnt/sdb12

LAB #12 - Converting Ext2 to Ext3

[root@centos8 ~]# umount /mnt/sdb12
[root@centos8 ~]# tune2fs -j /dev/sdb12
tune2fs 1.45.6 (20-Mar-2020)
Creating journal inode: done

LAB #13 - Using another Partition for the Journal

[root@centos8 ~]# mke2fs -O journal_dev /dev/sdb11
mke2fs 1.45.6 (20-Mar-2020)
Creating filesystem with 512000 1k blocks and 0 inodes
Filesystem UUID: 23327281-e88a-4da0-bafa-50ee10c52937
Superblock backups stored on blocks:
Zeroing journal device:

Important : Note the -O switch.

[root@centos8 ~]# mke2fs -j -J device=/dev/sdb11 /dev/sdb12
mke2fs 1.45.6 (20-Mar-2020)
Using journal device's blocksize: 1024
/dev/sdb12 contains a ext3 file system
last mounted on Wed Jun 2 08:03:11 2021
Proceed anyway? (y,N) y
Creating filesystem with 204800 1k blocks and 51200 inodes
Filesystem UUID: 0e783411-6407-4cba-8db5-0e2729000c9e
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729
Allocating group tables: done
Writing inode tables: done
Adding journal to device /dev/sdb11: done
Writing superblocks and filesystem accounting information: done

LAB #14 - Changing the File System Check interval on an ext3 Filesystem

Use the -c or -i switches:

[root@centos8 ~]# tune2fs -i 100d /dev/sdb12
tune2fs 1.45.6 (20-Mar-2020)
Setting interval between checks to 8640000 seconds

[root@centos8 ~]# dumpe2fs /dev/sdb12 | grep UUID
dumpe2fs 1.45.6 (20-Mar-2020)
Filesystem UUID: 0e783411-6407-4cba-8db5-0e2729000c9e
Journal UUID: 23327281-e88a-4da0-bafa-50ee10c52937

Ext4

LAB #15 - Creating an Ext4 Filesystem

[root@centos8 ~]# mkfs.ext4 /dev/sdb11
mke2fs 1.45.6 (20-Mar-2020)
/dev/sdb11 contains a jbd file system
Proceed anyway? (y,N) y
Creating filesystem with 512000 1k blocks and 128016 inodes
Filesystem UUID: 72a6ad08-7023-4561-adcb-d434e00afed1
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729, 204801, 221185, 401409
Allocating group tables: done
Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done

The command line switches of this command are:

[root@centos8 ~]# mkfs.ext4 --help
mkfs.ext4: invalid option -- '-'
Usage: mkfs.ext4 [-c|-l filename] [-b block-size] [-C cluster-size]
[-i bytes-per-inode] [-I inode-size] [-J journal-options]
[-G flex-group-size] [-N number-of-inodes] [-d root-directory]
[-m reserved-blocks-percentage] [-o creator-os]
[-g blocks-per-group] [-L volume-label] [-M last-mounted-directory]
[-O feature[,...]] [-r fs-revision] [-E extended-option[,...]]
[-t fs-type] [-T usage-type ] [-U UUID] [-e errors_behavior][-z undo_file]
[-jnqvDFSV] device [blocks-count]

[root@centos8 ~]# dumpe2fs /dev/sdb11 | more
dumpe2fs 1.45.6 (20-Mar-2020)
Filesystem volume name: <none>
Last mounted on: <not available>
Filesystem UUID: 72a6ad08-7023-4561-adcb-d434e00afed1
Filesystem magic number: 0xEF53
Filesystem revision #: 1 (dynamic)
Filesystem features: has_journal ext_attr resize_inode dir_index filetype e
xtent 64bit flex_bg sparse_super large_file huge_file dir_nlink extra_isize meta
data_csum
Filesystem flags: signed_directory_hash
Default mount options: user_xattr acl
Filesystem state: clean
Errors behavior: Continue
Filesystem OS type: Linux
Inode count: 128016
Block count: 512000
Reserved block count: 25600
Free blocks: 485316
Free inodes: 128005
First block: 1
Block size: 1024
Fragment size: 1024
Group descriptor size: 64
Reserved GDT blocks: 256
--More--

LAB #16 - Adding a Label to an Ext4 Filesystem

[root@centos8 ~]# e2label /dev/sdb11 my_ext4
[root@centos8 ~]# dumpe2fs /dev/sdb11 | more
dumpe2fs 1.45.6 (20-Mar-2020)
Filesystem volume name: my_ext4
Last mounted on: <not available>
Filesystem UUID: 72a6ad08-7023-4561-adcb-d434e00afed1
Filesystem magic number: 0xEF53
Filesystem revision #: 1 (dynamic)
Filesystem features: has_journal ext_attr resize_inode dir_index filetype e
xtent 64bit flex_bg sparse_super large_file huge_file dir_nlink extra_isize meta
data_csum
Filesystem flags: signed_directory_hash
Default mount options: user_xattr acl
Filesystem state: clean
Errors behavior: Continue
Filesystem OS type: Linux
Inode count: 128016
Block count: 512000
Reserved block count: 25600
Free blocks: 485316
Free inodes: 128005
First block: 1
Block size: 1024
Fragment size: 1024
Group descriptor size: 64
Reserved GDT blocks: 256
--More--

Important - Note that the labal is limited to 16 characters.

[root@centos8 ~]# mkdir /mnt/sdb11
[root@centos8 ~]# mount -t ext3 /dev/sdb11 /mnt/sdb11
mount: /mnt/sdb11: wrong fs type, bad option, bad superblock on /dev/sdb11, missing codepage or helper program, or other error..

[root@centos8 ~]# mount /dev/sdb11 /mnt/sdb11
[root@centos8 ~]# mount | grep sdb11
/dev/sdb11 on /mnt/sdb11 type ext4 (rw,relatime,seclabel)

LAB #17 - Converting Ext3 to Ext4

[root@centos8 ~]# mkfs.ext3 /dev/sdb12
mke2fs 1.45.6 (20-Mar-2020)
/dev/sdb12 contains a ext3 file system
created on Wed Jun 2 08:10:40 2021
Proceed anyway? (y,N) y
Creating filesystem with 204800 1k blocks and 51200 inodes
Filesystem UUID: b73322d4-f2e4-43bc-96ae-422d4584f3de
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729
Allocating group tables: done
Writing inode tables: done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done

[root@centos8 ~]# mount /dev/sdb12 /mnt/sdb12
[root@centos8 ~]# ls -l /mnt/sdb12
total 12
drwx------. 2 root root 12288 Jun 2 08:42 lost+found

[root@centos8 ~]# touch /mnt/sdb12/check_file

[root@centos8 ~]# echo "check file" > /mnt/sdb12/check_file
[root@centos8 ~]# umount /dev/sdb12

[root@centos8 ~]# e2fsck /dev/sdb12
e2fsck 1.45.6 (20-Mar-2020)
/dev/sdb12: clean, 12/51200 files, 12128/204800 blocks

[root@centos8 ~]# tune2fs -O extents,uninit_bg,dir_index /dev/sdb12
tune2fs 1.45.6 (20-Mar-2020)

[root@centos8 ~]# e2fsck -fDC0 /dev/sdb12
e2fsck 1.45.6 (20-Mar-2020)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 3A: Optimizing directories
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/sdb12: ***** FILE SYSTEM WAS MODIFIED *****
/dev/sdb12: 12/51200 files (0.0% non-contiguous), 12128/204800 blocks

[root@centos8 ~]# mount -t ext3 /dev/sdb12 /mnt/sdb12
mount: /mnt/sdb12: wrong fs type, bad option, bad superblock on /dev/sdb12, missing codepage or helper program, or other error.

[root@centos8 ~]# mount /dev/sdb12 /mnt/sdb12
[root@centos8 ~]# ls -l /mnt/sdb12
total 14
-rw-r--r--. 1 root root 11 Jun 2 08:45 check_file
drwx------. 2 root root 12288 Jun 2 08:42 lost+found
[root@centos8 ~]# cat /mnt/sdb12/check_file
check file

[root@centos8 ~]# dumpe2fs /dev/sdb11 | grep UUID
dumpe2fs 1.45.6 (20-Mar-2020)
Filesystem UUID: 72a6ad08-7023-4561-adcb-d434e00afed1
[root@centos8 ~]# dumpe2fs /dev/sdb12 | grep UUID
dumpe2fs 1.45.6 (20-Mar-2020)
Filesystem UUID: b73322d4-f2e4-43bc-96ae-422d4584f3de

XFS

Important : XFS allows you to extend a filesystem but not reduce it.

LAB #18 - Creating an XFS Filesystem

[root@centos8 ~]# umount /dev/sdb12

[root@centos8 ~]# mkfs.xfs -f /dev/sdb12
meta-data=/dev/sdb12 isize=512 agcount=4, agsize=12800 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=0
= reflink=1
data = bsize=4096 blocks=51200, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1
log =internal log bsize=4096 blocks=1368, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0

Important - Note the use of the -f switch.

The command line switches of this command are:

[root@centos8 ~]# mkfs.xfs --help
mkfs.xfs: invalid option -- '-'
unknown option --
Usage: mkfs.xfs
/* blocksize */	[-b size=num]
/* metadata */	[-m crc=0|1,finobt=0|1,uuid=xxx,rmapbt=0|1,reflink=0|1]
/* data subvol */	[-d agcount=n,agsize=n,file,name=xxx,size=num,
(sunit=value,swidth=value|su=num,sw=num|noalign),
sectsize=num
/* force overwrite */	[-f]
/* inode size */	[-i log=n|perblock=n|size=num,maxpct=n,attr=0|1|2,
projid32bit=0|1,sparse=0|1]
/* no discard */	[-K]
/* log subvol */	[-l agnum=n,internal,size=num,logdev=xxx,version=n
sunit=value|su=num,sectsize=num,lazy-count=0|1]
/* label */	[-L label (maximum 12 characters)]
/* naming */	[-n size=num,version=2|ci,ftype=0|1]
/* no-op info only */	[-N]
/* prototype file */	[-p fname]
/* quiet */	[-q]
/* realtime subvol */	[-r extsize=num,size=num,rtdev=xxx]
/* sectorsize */	[-s size=num]
/* version */	[-V]
devicename
<devicename> is required unless -d name=xxx is given.
<num> is xxx (bytes), xxxs (sectors), xxxb (fs blocks), xxxk (xxx KiB),
xxxm (xxx MiB), xxxg (xxx GiB), xxxt (xxx TiB) or xxxp (xxx PiB).
<value> is xxx (512 byte blocks).

[root@centos8 ~]# xfs_info /dev/sdb12
meta-data=/dev/sdb12 isize=512 agcount=4, agsize=12800 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=0
= reflink=1
data = bsize=4096 blocks=51200, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1
log =internal log bsize=4096 blocks=1368, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0

The command line switches of this command are:

[root@centos8 ~]# xfs_info --help
/usr/sbin/xfs_info: illegal option -- -
Usage: xfs_info [-V] [-t mtab] [mountpoint|device|file]

===LAB #19 - Adding a Label to an XFS Filesyst

[root@centos8 ~]# xfs_admin -L my_xfs /dev/sdb12
xfs_admin: /dev/sdb12 contains a mounted filesystem
fatal error -- couldn't initialize XFS library
[root@centos8 ~]# umount /dev/sdb12
[root@centos8 ~]# xfs_admin -L my_xfs /dev/sdb12
writing all SBs
new label = "my_xfs"

Pour voir l'étiquette, utilisez la commande suivante :

[root@centos8 ~]# xfs_admin -l /dev/sdb12
label = "my_xfs"

Important - Note the Label cannot be longer that 12 characters.

The command line switches of this command are:

[root@centos8 ~]# xfs_admin --help
/usr/sbin/xfs_admin: illegal option -- -
Usage: xfs_admin [-efjlpuV] [-c 0|1] [-L label] [-U uuid] device

[root@centos8 ~]# xfs_admin -u /dev/sdb12
UUID = 15db1b62-0866-4aa4-9ac1-3ac325a4e20f

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