LCF506 - Gestion de l'Archivage et de la Compression

• LCF506 - Gestion de l'Archivage et de la Compression
  • Contenu du Module
  • Types de Sauvegardes
    • Sauvegarde complète
    • Sauvegarde différentielle
    • Sauvegarde incrémentale
    • Sauvegarde décrémentale
  • Outils Classiques de Sauvegarde
    • Préparation
    • La Commande tar
      • Présentation
      • LAB #1 - Travailler avec la Commande tar
      • La Commande GPL tar et la Compression
    • La Commande cpio
      • Présentation
      • LAB #2 - Travailler avec la Commande cpio
    • La Commande dd
      • Présentation
      • LAB #3 - Travailler avec la Commande dd
    • Les Commandes dump et restore
      • Présentation
  • Outils Avancés de Sauvegarde
    • Outils de Sauvegarde Unidirectionnelle
    • Outils de Sauvegarde Multidirectionnelle
    • Outils de Sauvegarde des Partitions
    • LAB #4 - Que Sauvegarder en Priorité ?
      • Sauvegarde de la Liste des Paquets
      • Sauvegarde d'un Mémo sur la Structure du Disque Dur Système
      • Sauvegarde d'un Mémo sur les Points de Montage du Disque Dur Système
      • Sauvegarde du Chargeur de Démarrage
        • GRUB Legacy
        • GRUB 2 avec BIOS
        • GRUB 2 avec EFI
      • Sauvegarde des Dossiers Utilisateurs
    • LAB #5 - Rsync
      • Présentation
      • Travailler avec la Commande rsync
  • Compression
    • La Commande gzip
      • Présentation
      • LAB #4 - Travaller avec la Commande gzip
    • La Commande bzip2
      • Présentation
      • LAB #5 - Travailler avec la Commande bzip2
    • La Commande xz
      • Présentation
      • LAB #6 - Travailler avec la Commande xz
    • Autres Utilitaires

Dans ce cas on sauvegarde tous les fichiers et dossiers, toute la partition ou tout le disque :

La restauration nécessite :

• La dernière sauvegarde complète.

Avantage :

• Restauration plus rapide et plus simple que les restaurations à partir de sauvegardes différentielles et incrémentales.

Inconvénient :

• Nécessite plus d'espace de stockage que les sauvegardes différentielles et incrémentales.

Dans ce cas on sauvegarde des données modifiées ou nouvellement ajoutées sur la base de la dernière sauvegarde complète :

La restauration nécessite :

• La dernière sauvegarde complète,
• La dernière sauvegarde différentielle.

Avantage :

• Restauration plus rapide que la restauration à partir d'une sauvegarde incrémentale.

Inconvénient :

• Nécessite plus d'espace de stockage que la sauvegarde incrémentale.

Dans ce cas, on ne sauvegarde que ce qui a changé depuis la dernière sauvegarde quelle qu'elle soit (complète, différentielle ou incrémentale) :

La restauration nécessite :

• La dernière sauvegarde complète,
• Toutes les sauvegardes incrémentales effectuées depuis, et dans l'ordre.

Avantage :

• Sauvegarde plus rapide que la sauvegarde complète ou différentielle,
• Nécessite moins d'espace de stockage que la sauvegarde différentielle.

Inconvénient :

• Plus longue à restaurer.

Dans ce cas on sauvegarde tous les fichiers puis on produit une sauvegarde de ce qui a changé depuis la dernière sauvegarde complète. Cette sauvegarde est appelée une sauvegarde décrémentale :

La restauration nécessite :

• La dernière sauvegarde complète.

La restauration de J-1 nécessite :

• La dernière sauvegarde complète,
• La sauvegarde décrémentale J.

Par exemple pour obtenir un état du système J1 quand on est à J2, il convient de restaurer la sauvegarde complète de J2 qui est en réalité J2+J1 puis la sauvegarde décrémentale -J2. De cette façon et d'une manière mathématique on obtient : J2 + J1 -J2 = J1.

Avantage :

• Restauration plus rapide et plus simple que les restaurations à partir de sauvegardes différentielles et incrémentales.

Inconvénient :

• Nécessite plus de manipulation de données à chaque sauvegarde.

Afin de poursuivre, il convient de créer une arborescence à sauvegarder :

[root@centos8 ~]# mkdir -p /test/repY; mkdir /test/repZ
[root@centos8 ~]# cd /test/repY; touch Y1 Y2 Y3
[root@centos8 repY]# cd /test/repZ; touch Z1 Z2
[root@centos8 repZ]# ls -lR /test
/test:
total 0
drwxr-xr-x. 2 root root 36 Jun  2 14:05 repY
drwxr-xr-x. 2 root root 26 Jun  2 14:05 repZ

/test/repY:
total 0
-rw-r--r--. 1 root root 0 Jun  2 14:05 Y1
-rw-r--r--. 1 root root 0 Jun  2 14:05 Y2
-rw-r--r--. 1 root root 0 Jun  2 14:05 Y3

/test/repZ:
total 0
-rw-r--r--. 1 root root 0 Jun  2 14:05 Z1
-rw-r--r--. 1 root root 0 Jun  2 14:05 Z2

Le programme tar a été originellement prévu pour sauvegarder sur des bandes magnétiques, d'où son nom issu de tape archiver.

La commande tar peut sauvegarder vers :

• un fichier spécial, par exemple le nom d'un lecteur de bande,
• un fichier ordinaire sur disque,
• la sortie standard pour être utilisé dans un pipe.

Les options de la commande tar sont :

[root@centos8 repZ]# tar --help
Usage: tar [OPTION...] [FILE]...
GNU 'tar' saves many files together into a single tape or disk archive, and can
restore individual files from the archive.

Examples:
  tar -cf archive.tar foo bar  # Create archive.tar from files foo and bar.
  tar -tvf archive.tar         # List all files in archive.tar verbosely.
  tar -xf archive.tar          # Extract all files from archive.tar.

 Local file name selection:

      --add-file=FILE        add given FILE to the archive (useful if its name
                             starts with a dash)
  -C, --directory=DIR        change to directory DIR
      --exclude=PATTERN      exclude files, given as a PATTERN
      --exclude-backups      exclude backup and lock files
      --exclude-caches       exclude contents of directories containing
                             CACHEDIR.TAG, except for the tag file itself
      --exclude-caches-all   exclude directories containing CACHEDIR.TAG
      --exclude-caches-under exclude everything under directories containing
                             CACHEDIR.TAG
      --exclude-ignore=FILE  read exclude patterns for each directory from
                             FILE, if it exists
      --exclude-ignore-recursive=FILE
                             read exclude patterns for each directory and its
                             subdirectories from FILE, if it exists
      --exclude-tag=FILE     exclude contents of directories containing FILE,
                             except for FILE itself
      --exclude-tag-all=FILE exclude directories containing FILE
      --exclude-tag-under=FILE   exclude everything under directories
                             containing FILE
      --exclude-vcs          exclude version control system directories
      --exclude-vcs-ignores  read exclude patterns from the VCS ignore files
      --no-null              disable the effect of the previous --null option
      --no-recursion         avoid descending automatically in directories
      --no-unquote           do not unquote input file or member names
      --no-verbatim-files-from   -T treats file names starting with dash as
                             options (default)
      --null                 -T reads null-terminated names; implies
                             --verbatim-files-from
      --recursion            recurse into directories (default)
  -T, --files-from=FILE      get names to extract or create from FILE
      --unquote              unquote input file or member names (default)
      --verbatim-files-from  -T reads file names verbatim (no escape or option
                             handling)
  -X, --exclude-from=FILE    exclude patterns listed in FILE

 File name matching options (affect both exclude and include patterns):

      --anchored             patterns match file name start
      --ignore-case          ignore case
      --no-anchored          patterns match after any '/' (default for
                             exclusion)
      --no-ignore-case       case sensitive matching (default)
      --no-wildcards         verbatim string matching
      --no-wildcards-match-slash   wildcards do not match '/'
      --wildcards            use wildcards (default)
      --wildcards-match-slash   wildcards match '/' (default for exclusion)

 Main operation mode:

  -A, --catenate, --concatenate   append tar files to an archive
  -c, --create               create a new archive
  -d, --diff, --compare      find differences between archive and file system
      --delete               delete from the archive (not on mag tapes!)
  -r, --append               append files to the end of an archive
  -t, --list                 list the contents of an archive
      --test-label           test the archive volume label and exit
  -u, --update               only append files newer than copy in archive
  -x, --extract, --get       extract files from an archive

 Operation modifiers:

      --check-device         check device numbers when creating incremental
                             archives (default)
  -g, --listed-incremental=FILE   handle new GNU-format incremental backup
  -G, --incremental          handle old GNU-format incremental backup
      --hole-detection=TYPE  technique to detect holes
      --ignore-failed-read   do not exit with nonzero on unreadable files
      --level=NUMBER         dump level for created listed-incremental archive
  -n, --seek                 archive is seekable
      --no-check-device      do not check device numbers when creating
                             incremental archives
      --no-seek              archive is not seekable
      --occurrence[=NUMBER]  process only the NUMBERth occurrence of each file
                             in the archive; this option is valid only in
                             conjunction with one of the subcommands --delete,
                             --diff, --extract or --list and when a list of
                             files is given either on the command line or via
                             the -T option; NUMBER defaults to 1
      --sparse-version=MAJOR[.MINOR]
                             set version of the sparse format to use (implies
                             --sparse)
  -S, --sparse               handle sparse files efficiently

 Overwrite control:

  -k, --keep-old-files       don't replace existing files when extracting,
                             treat them as errors
      --keep-directory-symlink   preserve existing symlinks to directories when
                             extracting
      --keep-newer-files     don't replace existing files that are newer than
                             their archive copies
      --no-overwrite-dir     preserve metadata of existing directories
      --one-top-level[=DIR]  create a subdirectory to avoid having loose files
                             extracted
      --overwrite            overwrite existing files when extracting
      --overwrite-dir        overwrite metadata of existing directories when
                             extracting (default)
      --recursive-unlink     empty hierarchies prior to extracting directory
      --remove-files         remove files after adding them to the archive
      --skip-old-files       don't replace existing files when extracting,
                             silently skip over them
  -U, --unlink-first         remove each file prior to extracting over it
  -W, --verify               attempt to verify the archive after writing it

 Select output stream:

      --ignore-command-error ignore exit codes of children
      --no-ignore-command-error   treat non-zero exit codes of children as
                             error
  -O, --to-stdout            extract files to standard output
      --to-command=COMMAND   pipe extracted files to another program

 Handling of file attributes:

      --atime-preserve[=METHOD]   preserve access times on dumped files, either
                             by restoring the times after reading
                             (METHOD='replace'; default) or by not setting the
                             times in the first place (METHOD='system')
      --clamp-mtime          only set time when the file is more recent than
                             what was given with --mtime
      --delay-directory-restore   delay setting modification times and
                             permissions of extracted directories until the end
                             of extraction
      --group=NAME           force NAME as group for added files
      --group-map=FILE       use FILE to map file owner GIDs and names
      --mode=CHANGES         force (symbolic) mode CHANGES for added files
      --mtime=DATE-OR-FILE   set mtime for added files from DATE-OR-FILE
  -m, --touch                don't extract file modified time
      --no-delay-directory-restore
                             cancel the effect of --delay-directory-restore
                             option
      --no-same-owner        extract files as yourself (default for ordinary
                             users)
      --no-same-permissions  apply the user's umask when extracting permissions
                             from the archive (default for ordinary users)
      --numeric-owner        always use numbers for user/group names
      --owner=NAME           force NAME as owner for added files
      --owner-map=FILE       use FILE to map file owner UIDs and names
  -p, --preserve-permissions, --same-permissions
                             extract information about file permissions
                             (default for superuser)
      --same-owner           try extracting files with the same ownership as
                             exists in the archive (default for superuser)
  -s, --preserve-order, --same-order
                             member arguments are listed in the same order as
                             the files in the archive
      --sort=ORDER           directory sorting order: none (default), name or
                             inode

 Handling of extended file attributes:

      --acls                 Enable the POSIX ACLs support
      --no-acls              Disable the POSIX ACLs support
      --no-selinux           Disable the SELinux context support
      --no-xattrs            Disable extended attributes support
      --selinux              Enable the SELinux context support
      --xattrs               Enable extended attributes support
      --xattrs-exclude=MASK  specify the exclude pattern for xattr keys
      --xattrs-include=MASK  specify the include pattern for xattr keys

 Device selection and switching:

  -f, --file=ARCHIVE         use archive file or device ARCHIVE
      --force-local          archive file is local even if it has a colon
  -F, --info-script=NAME, --new-volume-script=NAME
                             run script at end of each tape (implies -M)
  -L, --tape-length=NUMBER   change tape after writing NUMBER x 1024 bytes
  -M, --multi-volume         create/list/extract multi-volume archive
      --rmt-command=COMMAND  use given rmt COMMAND instead of rmt
      --rsh-command=COMMAND  use remote COMMAND instead of rsh
      --volno-file=FILE      use/update the volume number in FILE

 Device blocking:

  -b, --blocking-factor=BLOCKS   BLOCKS x 512 bytes per record
  -B, --read-full-records    reblock as we read (for 4.2BSD pipes)
  -i, --ignore-zeros         ignore zeroed blocks in archive (means EOF)
      --record-size=NUMBER   NUMBER of bytes per record, multiple of 512

 Archive format selection:

  -H, --format=FORMAT        create archive of the given format

 FORMAT is one of the following:

    gnu                      GNU tar 1.13.x format
    oldgnu                   GNU format as per tar <= 1.12
    pax                      POSIX 1003.1-2001 (pax) format
    posix                    same as pax
    ustar                    POSIX 1003.1-1988 (ustar) format
    v7                       old V7 tar format

      --old-archive, --portability
                             same as --format=v7
      --pax-option=keyword[[:]=value][,keyword[[:]=value]]...
                             control pax keywords
      --posix                same as --format=posix
  -V, --label=TEXT           create archive with volume name TEXT; at
                             list/extract time, use TEXT as a globbing pattern
                             for volume name

 Compression options:

  -a, --auto-compress        use archive suffix to determine the compression
                             program
  -I, --use-compress-program=PROG
                             filter through PROG (must accept -d)
  -j, --bzip2                filter the archive through bzip2
  -J, --xz                   filter the archive through xz
      --lzip                 filter the archive through lzip
      --lzma                 filter the archive through xz --format=lzma
      --lzop                 filter the archive through lzop
      --no-auto-compress     do not use archive suffix to determine the
                             compression program
  -z, --gzip, --gunzip, --ungzip   filter the archive through gzip
  -Z, --compress, --uncompress   filter the archive through compress

 Local file selection:

      --backup[=CONTROL]     backup before removal, choose version CONTROL
  -h, --dereference          follow symlinks; archive and dump the files they
                             point to
      --hard-dereference     follow hard links; archive and dump the files they
                             refer to
  -K, --starting-file=MEMBER-NAME
                             begin at member MEMBER-NAME when reading the
                             archive
      --newer-mtime=DATE     compare date and time when data changed only
  -N, --newer=DATE-OR-FILE, --after-date=DATE-OR-FILE
                             only store files newer than DATE-OR-FILE
      --one-file-system      stay in local file system when creating archive
  -P, --absolute-names       don't strip leading '/'s from file names
      --suffix=STRING        backup before removal, override usual suffix ('~'
                             unless overridden by environment variable
                             SIMPLE_BACKUP_SUFFIX)

 File name transformations:

      --strip-components=NUMBER   strip NUMBER leading components from file
                             names on extraction
      --transform=EXPRESSION, --xform=EXPRESSION
                             use sed replace EXPRESSION to transform file
                             names

 Informative output:

      --checkpoint[=NUMBER]  display progress messages every NUMBERth record
                             (default 10)
      --checkpoint-action=ACTION   execute ACTION on each checkpoint
      --full-time            print file time to its full resolution
      --index-file=FILE      send verbose output to FILE
  -l, --check-links          print a message if not all links are dumped
      --no-quote-chars=STRING   disable quoting for characters from STRING
      --quote-chars=STRING   additionally quote characters from STRING
      --quoting-style=STYLE  set name quoting style; see below for valid STYLE
                             values
  -R, --block-number         show block number within archive with each message
                            
      --show-defaults        show tar defaults
      --show-omitted-dirs    when listing or extracting, list each directory
                             that does not match search criteria
      --show-snapshot-field-ranges
                             show valid ranges for snapshot-file fields
      --show-transformed-names, --show-stored-names
                             show file or archive names after transformation
      --totals[=SIGNAL]      print total bytes after processing the archive;
                             with an argument - print total bytes when this
                             SIGNAL is delivered; Allowed signals are: SIGHUP,
                             SIGQUIT, SIGINT, SIGUSR1 and SIGUSR2; the names
                             without SIG prefix are also accepted
      --utc                  print file modification times in UTC
  -v, --verbose              verbosely list files processed
      --warning=KEYWORD      warning control
  -w, --interactive, --confirmation
                             ask for confirmation for every action

 Compatibility options:

  -o                         when creating, same as --old-archive; when
                             extracting, same as --no-same-owner

 Other options:

  -?, --help                 give this help list
      --restrict             disable use of some potentially harmful options
      --usage                give a short usage message
      --version              print program version

Mandatory or optional arguments to long options are also mandatory or optional
for any corresponding short options.

The backup suffix is '~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX.
The version control may be set with --backup or VERSION_CONTROL, values are:

  none, off       never make backups
  t, numbered     make numbered backups
  nil, existing   numbered if numbered backups exist, simple otherwise
  never, simple   always make simple backups

Valid arguments for the --quoting-style option are:

  literal
  shell
  shell-always
  shell-escape
  shell-escape-always
  c
  c-maybe
  escape
  locale
  clocale

*This* tar defaults to:
--format=gnu -f- -b20 --quoting-style=escape --rmt-command=/etc/rmt
--rsh-command=/usr/bin/ssh

Vous allez maintenant sauvegarder votre dossier test ainsi que son contenu vers un fichier :

[root@centos8 repZ]# tar cvf /tmp/test.tar /test
tar: Removing leading `/' from member names
/test/
/test/repY/
/test/repY/Y1
/test/repY/Y2
/test/repY/Y3
/test/repZ/
/test/repZ/Z1
/test/repZ/Z2

Pour visualiser la table of contents de votre sauvegarde, utilisez la commande suivante :

[root@centos8 repZ]# tar tvf /tmp/test.tar
drwxr-xr-x root/root         0 2021-06-02 14:04 test/
drwxr-xr-x root/root         0 2021-06-02 14:05 test/repY/
-rw-r--r-- root/root         0 2021-06-02 14:05 test/repY/Y1
-rw-r--r-- root/root         0 2021-06-02 14:05 test/repY/Y2
-rw-r--r-- root/root         0 2021-06-02 14:05 test/repY/Y3
drwxr-xr-x root/root         0 2021-06-02 14:05 test/repZ/
-rw-r--r-- root/root         0 2021-06-02 14:05 test/repZ/Z1
-rw-r--r-- root/root         0 2021-06-02 14:05 test/repZ/Z2

Afin de créer une sauvegarde incrémentale, vous avez besoin de créer un fichier qui servira de référence de date :

[root@centos8 repZ]# touch /tmp/dateref

Modifiez maintenant deux des fichiers de votre arborescence test :

[root@centos8 repZ]# echo "CentOS est super \!" > /test/repY/Y1
[root@centos8 repZ]# echo "RHEL is wonderful \!" > /test/repZ/Z1

Pour procéder à votre sauvegarde incrémentale, vous devez sauvegarder uniquement les fichiers modifiés ou créés depuis la création de votre fichier /tmp/dateref.

Saisissez donc la commande suivante :

[root@centos8 repZ]# tar -cvf /tmp/incremental.tar -N /tmp/dateref /test
tar: Removing leading `/' from member names
/test/
/test/repY/
/test/repY/Y1
tar: /test/repY/Y2: file is unchanged; not dumped
tar: /test/repY/Y3: file is unchanged; not dumped
/test/repZ/
/test/repZ/Z1
tar: /test/repZ/Z2: file is unchanged; not dumped

Contrôlez maintenant le contenu de l'archive /tmp/incremental.tar :

[root@centos8 repZ]# tar tvf /tmp/incremental.tar
drwxr-xr-x root/root         0 2021-06-02 14:04 test/
drwxr-xr-x root/root         0 2021-06-02 14:05 test/repY/
-rw-r--r-- root/root        20 2021-06-02 14:08 test/repY/Y1
drwxr-xr-x root/root         0 2021-06-02 14:05 test/repZ/
-rw-r--r-- root/root        21 2021-06-02 14:09 test/repZ/Z1

Supprimez maintenant le contenu du répertoire test :

[root@centos8 repZ]# rm -rf /test/*

Afin de pouvoir restaurer les fichiers de votre première sauvegarde, placez-vous à la racine de votre système et restaurez le contenu de votre répertoire test en saisissant la commande tar suivante :

[root@centos8 repZ]# cd /
[root@centos8 /]# tar xvf /tmp/test.tar
test/
test/repY/
test/repY/Y1
test/repY/Y2
test/repY/Y3
test/repZ/
test/repZ/Z1
test/repZ/Z2

Constatez maintenant que l'opération s'est bien déroulée :

[root@centos8 /]# ls -lR /test
/test:
total 0
drwxr-xr-x. 2 root root 36 Jun  2 14:05 repY
drwxr-xr-x. 2 root root 26 Jun  2 14:05 repZ

/test/repY:
total 0
-rw-r--r--. 1 root root 0 Jun  2 14:05 Y1
-rw-r--r--. 1 root root 0 Jun  2 14:05 Y2
-rw-r--r--. 1 root root 0 Jun  2 14:05 Y3

/test/repZ:
total 0
-rw-r--r--. 1 root root 0 Jun  2 14:05 Z1
-rw-r--r--. 1 root root 0 Jun  2 14:05 Z2

Restaurez maintenant votre archive incrémentale :

[root@centos8 /]# tar xvf /tmp/incremental.tar
test/
test/repY/
test/repY/Y1
test/repZ/
test/repZ/Z1

Constatez maintenant que l'opération s'est bien déroulée :

[root@centos8 /]# ls -lR /test
/test:
total 0
drwxr-xr-x. 2 root root 36 Jun  2 14:05 repY
drwxr-xr-x. 2 root root 26 Jun  2 14:05 repZ

/test/repY:
total 4
-rw-r--r--. 1 root root 20 Jun  2 14:08 Y1
-rw-r--r--. 1 root root  0 Jun  2 14:05 Y2
-rw-r--r--. 1 root root  0 Jun  2 14:05 Y3

/test/repZ:
total 4
-rw-r--r--. 1 root root 21 Jun  2 14:09 Z1
-rw-r--r--. 1 root root  0 Jun  2 14:05 Z2

Dernièrement, la commande tar peut archiver en utilisant des algorithmes de compression :

La commande cpio (Copy Input To Output). cpio peut gérer les archives au format tar. La différence majeure entre tar et cpio est que ce dernier stocke les chemins d'accès aux fichiers sauvgardés en même temps que les fichiers eux-mêmes. Ceci implique que dans le cas où le chemin absolu a été spécifié lors de la sauvegarde, il est impossible de restaurer un fichier à un autre emplacement que son emplacement d'origine.

Vous allez utiliser maintenant le logiciel cpio pour effectuer les sauvegardes et restaurations.

Les options de la commande cpio sont :

[root@centos8 /]# cpio --help
Usage: cpio [OPTION...] [destination-directory]
GNU `cpio' copies files to and from archives

Examples:
  # Copy files named in name-list to the archive
  cpio -o < name-list [> archive]
  # Extract files from the archive
  cpio -i [< archive]
  # Copy files named in name-list to destination-directory
  cpio -p destination-directory < name-list

 Main operation mode:
  -i, --extract              Extract files from an archive (run in copy-in
                             mode)
  -o, --create               Create the archive (run in copy-out mode)
  -p, --pass-through         Run in copy-pass mode
  -t, --list                 Print a table of contents of the input

 Operation modifiers valid in any mode:

      --block-size=BLOCK-SIZE   Set the I/O block size to BLOCK-SIZE * 512
                             bytes
  -B                         Set the I/O block size to 5120 bytes
  -c                         Identical to "-H newc", use the new (SVR4)
                             portable format. If you wish the old portable
                             (ASCII) archive format, use "-H odc" instead.
  -C, --io-size=NUMBER       Set the I/O block size to the given NUMBER of
                             bytes
  -D, --directory=DIR        Change to directory DIR
      --force-local          Archive file is local, even if its name contains
                             colons
  -H, --format=FORMAT        Use given archive FORMAT
      --quiet                Do not print the number of blocks copied
  -R, --owner=[USER][:.][GROUP]   Set the ownership of all files created to the
                             specified USER and/or GROUP
  -v, --verbose              Verbosely list the files processed
  -V, --dot                  Print a "." for each file processed
  -W, --warning=FLAG         Control warning display. Currently FLAG is one of
                             'none', 'truncate', 'all'. Multiple options
                             accumulate.

 Operation modifiers valid in copy-in and copy-out modes

  -F, --file=[[USER@]HOST:]FILE-NAME
                             Use this FILE-NAME instead of standard input or
                             output. Optional USER and HOST specify the user
                             and host names in case of a remote archive
  -M, --message=STRING       Print STRING when the end of a volume of the
                             backup media is reached
      --rsh-command=COMMAND  Use COMMAND instead of rsh

 Operation modifiers valid only in copy-in mode:

  -b, --swap                 Swap both halfwords of words and bytes of
                             halfwords in the data. Equivalent to -sS
  -f, --nonmatching          Only copy files that do not match any of the given
                             patterns
  -I [[USER@]HOST:]FILE-NAME Archive filename to use instead of standard input.
                             Optional USER and HOST specify the user and host
                             names in case of a remote archive
  -n, --numeric-uid-gid      In the verbose table of contents listing, show
                             numeric UID and GID
  -r, --rename               Interactively rename files
  -s, --swap-bytes           Swap the bytes of each halfword in the files
  -S, --swap-halfwords       Swap the halfwords of each word (4 bytes) in the
                             files
      --to-stdout            Extract files to standard output

  -E, --pattern-file=FILE    Read additional patterns specifying filenames to
                             extract or list from FILE
      --only-verify-crc      When reading a CRC format archive, only verify the
                             checksum of each file in the archive, don't
                             actually extract the files

 Operation modifiers valid only in copy-out mode:

  -A, --append               Append to an existing archive.
      --device-independent, --reproducible
                             Create device-independent (reproducible) archives
      --ignore-devno         Don't store device numbers
  -O [[USER@]HOST:]FILE-NAME Archive filename to use instead of standard
                             output. Optional USER and HOST specify the user
                             and host names in case of a remote archive
      --renumber-inodes      Renumber inodes

 Operation modifiers valid only in copy-pass mode:

  -l, --link                 Link files instead of copying them, when
                             possible

 Operation modifiers valid in copy-in and copy-out modes:

      --absolute-filenames   Do not strip file system prefix components from
                             the file names
      --no-absolute-filenames   Create all files relative to the current
                             directory

 Operation modifiers valid in copy-out and copy-pass modes:

  -0, --null                 Filenames in the list are delimited by null
                             characters instead of newlines
  -a, --reset-access-time    Reset the access times of files after reading
                             them
  -L, --dereference          Dereference  symbolic  links  (copy  the files
                             that they point to instead of copying the links).

 Operation modifiers valid in copy-in and copy-pass modes:

  -d, --make-directories     Create leading directories where needed
  -m, --preserve-modification-time
                             Retain previous file modification times when
                             creating files
      --no-preserve-owner    Do not change the ownership of the files
      --sparse               Write files with large blocks of zeros as sparse
                             files
  -u, --unconditional        Replace all files unconditionally

  -?, --help                 give this help list
      --usage                give a short usage message
      --version              print program version

Mandatory or optional arguments to long options are also mandatory or optional
for any corresponding short options.

Report bugs to <bug-cpio@gnu.org>.

Dans un premier temps, vous devez utiliser la commande find pour construire une liste de fichiers à sauvegarder :

[root@centos8 /]# find /test > /tmp/cpio.list
[root@centos8 /]# cat /tmp/cpio.list
/test
/test/repY
/test/repY/Y2
/test/repY/Y3
/test/repY/Y1
/test/repZ
/test/repZ/Z2
/test/repZ/Z1

Sauvegardez maintenant les fichiers et répertoires référencés par le fichier /tmp/cpio.list :

[root@centos8 /]# cpio -ov < /tmp/cpio.list > /tmp/test.cpio
/test
/test/repY
/test/repY/Y2
/test/repY/Y3
/test/repY/Y1
/test/repZ
/test/repZ/Z2
/test/repZ/Z1
1 block

Consultez maintenant la table of contents de votre sauvegarde :

[root@centos8 /]# cpio -it < /tmp/test.cpio
/test
/test/repY
/test/repY/Y2
/test/repY/Y3
/test/repY/Y1
/test/repZ
/test/repZ/Z2
/test/repZ/Z1
1 block

Supprimez maintenant le répertoire /test/repY et son contenu :

[root@centos8 /]# rm -rf /test/repY

Contrôlez le bon déroulement de la suppression :

[root@centos8 /]# ls -lR /test
/test:
total 0
drwxr-xr-x. 2 root root 26 Jun  2 14:05 repZ

/test/repZ:
total 4
-rw-r--r--. 1 root root 21 Jun  2 14:09 Z1
-rw-r--r--. 1 root root  0 Jun  2 14:05 Z2

Restaurez les fichiers supprimés :

[root@centos8 /]# cpio -ivdum "/test/repY/*" < /tmp/test.cpio
/test/repY/Y2
/test/repY/Y3
/test/repY/Y1
1 block

Contrôlez le bon déroulement de la restauration :

[root@centos8 /]# ls -lR /test
/test:
total 0
drwxr-xr-x. 2 root root 36 Jun  2 14:17 repY
drwxr-xr-x. 2 root root 26 Jun  2 14:05 repZ

/test/repY:
total 4
-rw-r--r--. 1 root root 20 Jun  2 14:08 Y1
-rw-r--r--. 1 root root  0 Jun  2 14:05 Y2
-rw-r--r--. 1 root root  0 Jun  2 14:05 Y3

/test/repZ:
total 4
-rw-r--r--. 1 root root 21 Jun  2 14:09 Z1
-rw-r--r--. 1 root root  0 Jun  2 14:05 Z2

La commande dd n'est pas réellement une commande de sauvegarde.

La commande dd copie le fichier passé en entrée dans le fichier de sortie en limitant le nombre d'octets copiés par l'utilisation de deux options :

• count
  • le nombre
• bs
  • la taille du bloc à copier

Les options de la commande dd sont :

[root@centos8 /]# dd --help
Usage: dd [OPERAND]...
  or:  dd OPTION
Copy a file, converting and formatting according to the operands.

  bs=BYTES        read and write up to BYTES bytes at a time (default: 512);
                  overrides ibs and obs
  cbs=BYTES       convert BYTES bytes at a time
  conv=CONVS      convert the file as per the comma separated symbol list
  count=N         copy only N input blocks
  ibs=BYTES       read up to BYTES bytes at a time (default: 512)
  if=FILE         read from FILE instead of stdin
  iflag=FLAGS     read as per the comma separated symbol list
  obs=BYTES       write BYTES bytes at a time (default: 512)
  of=FILE         write to FILE instead of stdout
  oflag=FLAGS     write as per the comma separated symbol list
  seek=N          skip N obs-sized blocks at start of output
  skip=N          skip N ibs-sized blocks at start of input
  status=LEVEL    The LEVEL of information to print to stderr;
                  'none' suppresses everything but error messages,
                  'noxfer' suppresses the final transfer statistics,
                  'progress' shows periodic transfer statistics

N and BYTES may be followed by the following multiplicative suffixes:
c =1, w =2, b =512, kB =1000, K =1024, MB =1000*1000, M =1024*1024, xM =M,
GB =1000*1000*1000, G =1024*1024*1024, and so on for T, P, E, Z, Y.

Each CONV symbol may be:

  ascii     from EBCDIC to ASCII
  ebcdic    from ASCII to EBCDIC
  ibm       from ASCII to alternate EBCDIC
  block     pad newline-terminated records with spaces to cbs-size
  unblock   replace trailing spaces in cbs-size records with newline
  lcase     change upper case to lower case
  ucase     change lower case to upper case
  sparse    try to seek rather than write the output for NUL input blocks
  swab      swap every pair of input bytes
  sync      pad every input block with NULs to ibs-size; when used
            with block or unblock, pad with spaces rather than NULs
  excl      fail if the output file already exists
  nocreat   do not create the output file
  notrunc   do not truncate the output file
  noerror   continue after read errors
  fdatasync  physically write output file data before finishing
  fsync     likewise, but also write metadata

Each FLAG symbol may be:

  append    append mode (makes sense only for output; conv=notrunc suggested)
  direct    use direct I/O for data
  directory  fail unless a directory
  dsync     use synchronized I/O for data
  sync      likewise, but also for metadata
  fullblock  accumulate full blocks of input (iflag only)
  nonblock  use non-blocking I/O
  noatime   do not update access time
  nocache   Request to drop cache.  See also oflag=sync
  noctty    do not assign controlling terminal from file
  nofollow  do not follow symlinks
  count_bytes  treat 'count=N' as a byte count (iflag only)
  skip_bytes  treat 'skip=N' as a byte count (iflag only)
  seek_bytes  treat 'seek=N' as a byte count (oflag only)

Sending a USR1 signal to a running 'dd' process makes it
print I/O statistics to standard error and then resume copying.

Options are:

      --help     display this help and exit
      --version  output version information and exit

GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Full documentation at: <https://www.gnu.org/software/coreutils/dd>
or available locally via: info '(coreutils) dd invocation'

Vous allez utiliser maintenant le logiciel dd pour effectuer une sauvegarde de votre MBR et de la table des partitions.

Effectuez une sauvegarde de votre MBR qui se trouve dans les premiers 446 octets de votre disque /dev/sda :

[root@centos8 /]# dd if=/dev/sda of=/tmp/mbr.save bs=1 count=446
446+0 records in
446+0 records out
446 bytes copied, 0.00202127 s, 221 kB/s

Effectuez maintenant une sauvegarde de votre table des partitions qui se trouve dans les 64 octets après les 446 précédemment sauvegardés :

[root@centos8 /]# dd if=/dev/sda of=/tmp/tblpart.save bs=1 count=64 skip=446
64+0 records in
64+0 records out
64 bytes copied, 0.000409593 s, 156 kB/s

Les commandes dump et restore se basent sur le format d'enregistrement des données ( ext3 ). Pour cette raison il n'est pas possible de sauvegarder des répertoires à l'intérieur d'un système de fichiers mais uniquement des systèmes de fichiers complets.

Il est important de noter que le système de fichier ne doit pas être utilisé pendant le processus de dump. Pour cette raison il est normalement conseillé de démonter le système de fichiers.

Il existe 10 niveaux de dump possibles de 0 à 9. Lors d'un dump le niveau est spécifié. Chaque fois qu'un dump est effectué, cette information est sauvegardée dans le fichier /etc/dumpdates.

Par définition un dump de niveau 0 est une sauvegarde complète tandis que le dump de niveau 1 est une sauvegarde incrémentale.

Notez que les fichiers sont sauvegardés avec des nom relatifs. Ceci implique que vous devez vous positionner dans le système de fichiers lors de la restauration avec la commande restore.

Ces outils sauvegardent des fichiers vers un répertoire local ou distant dans un seul sens.

Ce premier tableau compare les outils par rapport aux caractéristiques et aux capacités des opérations de sauvegarde :

Outil	Backend	Sauvegarde différentielle	Sauvegarde incrémentale	Sauvegarde décrémentale	Planification incorporée	Restauration incorporée	Chiffrement	Compression	Site
AMANDA	tar, gzip								AMANDA
Areca Backup	Aucun								Areca Backup
bacula (Bareos)	MySQL								bacula
BackInTime	rsync, diff, meld								BackInTime
BackupPC	rsync, samba, tar								BackupPC
Dar	Aucun								Dar
Déjà Dup	duplicity								Duplicity
Grsync	rsync								Grsync
luckyBackup	rsync								luckyBackup
SBackup	Aucun								SBackup

Ce deuxième tableau compare les outils triés par la date de dernière version connue :

Outil	Ecrit en	Licence	Dernière Version	Date Version	Linux	Windows	Mac	Site Web
Dar	C++	GPL	2.6.2	09/02/2019				Dar
Bacula (Bareos)	C, C++	GNU Affero General Public License v3.0	9.4.2	04/02/2019				bacula
BackupPC	Perl	GPL v3.0	4.3.0	25/11/2018				BackupPC
luckyBackup	C++	GPL v3.0	0.5.0	18/11/2018				luckyBackup
Déjà Dup (Duplicity)	Python	GPL	0.7.18.2	17/11/2018				Duplicity
AMANDA	C, Perl	GPL, LGPL, Apache, Amanda License	3.5.1	01/12/2017				AMANDA
BackInTime	Python3	GPL	1.1.24	07/11/2017				BackInTime
Grsync	GTK	GPL	1.2.6	15/03/2016				Grsync
Areca Backup	Java	GPLv2	7.5	26/08/2015				Areca Backup
SBackup	GTK	GPLv2	0.11.6	24/02/2014				SBackup

Ces outils synchronisent les fichiers entre deux serveurs.

Ce premier tableau compare les outils par rapport aux caractéristiques et aux capacités des opérations de sauvegarde :

Outil	Backend	Sauvegarde différentielle	Sauvegarde incrémentale	Sauvegarde décrémentale	Planification incorporée	Restauration incorporée	Chiffrement	Compression
FullSync	smb, ftp, sftp					S/O
FreeFileSync	Aucun					S/O
unison	SSH, RSH					S/O
Synkron	Aucun

Ce deuxième tableau compare les outils triés par la date de dernière version connue :

Outil	Ecrit en	Licence	Dernière Version	Date Version	Linux	Windows	Mac	Site Web
FreeFileSync	Divers	GPL v3.0	10.8	05/01/2019				FreeFileSync
unison	OCaml	GPL v3.0	2.51.2	27/01/2018				unison
FullSync	Java	GPLv2	0.10.4	05/04/2016				FullSync
Synkron	C++	GPL v2	1.6.2	25/01/2011				Synkron

Ce premier tableau compare les outils par rapport aux caractéristiques et aux capacités des opérations de sauvegarde :

Outil	Backend	Sauvegarde différentielle	Sauvegarde incrémentale	Sauvegarde décrémentale	Planification incorporée	Restauration incorporée	Chiffrement	Compression
CloneZilla	SSH, samba, NFS
Partclone	Aucun
partimage	Aucun

Ce deuxième tableau compare les outils triés par la date de dernière version connue :

Outil	Ecrit en	Licence	Dernière Version	Date Version	Linux	Windows	Mac	Site Web
CloneZilla	Perl, Unix shell	GPL	2.6.0-37	10/01/2019				CloneZilla
Partclone	C	GPL	0.2.89	05/07/2016				Partclone
partimage	C	GPL	0.6.9	25/07/2010				Partimage

Supprimez les fichiers de verrouillage de la base de données RPM :

[root@centos8 ~]# rm -f /var/lib/rpm/__db*

Sauvegardez les bases de données RPM :

[root@centos8 ~]# tar czvf $(hostname).rpmdatabase.tar.gz /var/lib/rpm
tar: Removing leading `/' from member names
/var/lib/rpm/
/var/lib/rpm/.dbenv.lock
/var/lib/rpm/Packages
/var/lib/rpm/Conflictname
/var/lib/rpm/Name
/var/lib/rpm/Basenames
/var/lib/rpm/Group
/var/lib/rpm/Requirename
/var/lib/rpm/Providename
/var/lib/rpm/Obsoletename
/var/lib/rpm/Triggername
/var/lib/rpm/Dirnames
/var/lib/rpm/Installtid
/var/lib/rpm/Sigmd5
/var/lib/rpm/Sha1header
/var/lib/rpm/Filetriggername
/var/lib/rpm/Transfiletriggername
/var/lib/rpm/Recommendname
/var/lib/rpm/Suggestname
/var/lib/rpm/Supplementname
/var/lib/rpm/Enhancename
/var/lib/rpm/.rpm.lock

Pour sauvegarder la liste des paquets à l'identique en termes de version, utilisez la commande RPM :

[root@centos8 ~]# rpm -qa > liste-des-paquets_`hostname`_`date +%Y-%m-%d-%H-%M``

Consultez le contenu de ce fichier :

[root@centos8 ~]# more liste-des-paquets_centos8.ittraining.loc_2021-06-02-15-04 
dracut-squash-049-95.git20200804.el8_3.4.x86_64
gnutls-dane-3.6.14-8.el8_3.x86_64
mtr-0.92-3.el8.x86_64
fontpackages-filesystem-1.44-22.el8.noarch
dhcp-libs-4.3.6-41.el8.x86_64
alsa-lib-1.2.3.2-1.el8.x86_64
geolite2-city-20180605-1.el8.noarch
cockpit-ws-224.2-1.el8.x86_64
python3-dbus-1.2.4-15.el8.x86_64
libvirt-daemon-config-network-6.0.0-28.1.module_el8.3.0+755+88436ea4.x86_64
samba-client-libs-4.12.3-12.el8.3.x86_64
libICE-1.0.9-15.el8.x86_64
bind-license-9.11.20-5.el8_3.1.noarch
dnf-4.2.23-4.el8.noarch
at-spi2-core-2.28.0-1.el8.x86_64
libssh-config-0.9.4-2.el8.noarch
bzip2-libs-1.0.6-26.el8.x86_64
python3-syspurpose-1.27.16-1.el8.x86_64
perl-Unicode-Normalize-1.25-396.el8.x86_64
centos-linux-release-8.3-1.2011.el8.noarch
sssd-krb5-2.3.0-9.el8.x86_64
perl-MIME-Base64-3.15-396.el8.x86_64
glibc-langpack-en-2.28-127.el8.x86_64
--More--(2%)

Afin de restaurer les sauvegardes, récupérez les deux fichiers liste-des-paquets_* et $(hostname).rpmdatabase.tar.gz du support externe à la racine du système de fichiers :

[root@centos8 ~]# cp liste-des-paquets_centos8.ittraining.loc_2021-06-02-15-04 centos8.ittraining.loc.rpmdatabase.tar.gz /

Placez-vous à la racine du système de fichiers et restaurez les bases de données RPM :

[root@centos8 ~]# cd /
[root@centos8 /]# tar xvf centos8.ittraining.loc.rpmdatabase.tar.gz 
var/lib/rpm/
var/lib/rpm/.dbenv.lock
var/lib/rpm/Packages
var/lib/rpm/Conflictname
var/lib/rpm/Name
var/lib/rpm/Basenames
var/lib/rpm/Group
var/lib/rpm/Requirename
var/lib/rpm/Providename
var/lib/rpm/Obsoletename
var/lib/rpm/Triggername
var/lib/rpm/Dirnames
var/lib/rpm/Installtid
var/lib/rpm/Sigmd5
var/lib/rpm/Sha1header
var/lib/rpm/Filetriggername
var/lib/rpm/Transfiletriggername
var/lib/rpm/Recommendname
var/lib/rpm/Suggestname
var/lib/rpm/Supplementname
var/lib/rpm/Enhancename
var/lib/rpm/.rpm.loc

Utilisez YUM pour restaurer les paquets :

[root@centos8 /]# yum -y install $(cat liste-des-paquets_centos8.ittraining.loc_2021-06-02-15-04)

[root@centos8 /]# cd ~
[root@centos8 ~]# fdisk -l /dev/sda > structure.list
[root@centos8 ~]# cat structure.list 
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

Saisissez la commande suivante :

[root@centos8 ~]# df -h | grep "^/dev/" > montages.list
[root@centos8 ~]# cat montages.list 
/dev/sda3        15G  2.7G   13G  18% /
/dev/sda1       283M  194M   70M  74% /boot

# cp /boot/grub/menu.lst grubmenu.lst

Saisissez les commandes suivantes :

[root@centos8 ~]# cp /boot/grub2/grub.cfg grub.cfg
[root@centos8 ~]# cp /boot/grub2/device.map device.map

# cp /boot/efi/EFI/redhat/grub.cfg grub.cfg
# cp /boot/grub2/device.map device.map

[root@centos8 ~]# cp -apv /home/ .
'/home/' -> './home'
'/home/trainee' -> './home/trainee'
'/home/trainee/.viminfo' -> './home/trainee/.viminfo'
'/home/trainee/typescript' -> './home/trainee/typescript'
'/home/trainee/bin' -> './home/trainee/bin'
'/home/trainee/bin/myscript' -> './home/trainee/bin/myscript'
'/home/trainee/abc' -> './home/trainee/abc'
'/home/trainee/bca' -> './home/trainee/bca'
'/home/trainee/file2' -> './home/trainee/file2'
'/home/trainee/xyz' -> './home/trainee/xyz'
'/home/trainee/file1' -> './home/trainee/file1'
'/home/trainee/file' -> './home/trainee/file'
'/home/trainee/.bash_logout' -> './home/trainee/.bash_logout'
'/home/trainee/.bash_profile' -> './home/trainee/.bash_profile'
'/home/trainee/.bashrc' -> './home/trainee/.bashrc'
'/home/trainee/.bash_history' -> './home/trainee/.bash_history'
'/home/trainee/tux.jpg' -> './home/trainee/tux.jpg'
'/home/trainee/tux1.jpg' -> './home/trainee/tux1.jpg'
'/home/trainee/pwd.txt' -> './home/trainee/pwd.txt'
'/home/trainee/errorlog' -> './home/trainee/errorlog'
'/home/trainee/backup.acl' -> './home/trainee/backup.acl'
'/home/trainee/aac' -> './home/trainee/aac'
'/home/trainee/rep1' -> './home/trainee/rep1'
'/home/trainee/rep1/fichier1' -> './home/trainee/rep1/fichier1'
'/home/trainee/rep1/backup.acl' -> './home/trainee/rep1/backup.acl'
'/home/trainee/training' -> './home/trainee/training'
'/home/trainee/training/f1' -> './home/trainee/training/f1'
'/home/trainee/training/f2' -> './home/trainee/training/f2'
'/home/trainee/training/f3' -> './home/trainee/training/f3'
'/home/trainee/training/f4' -> './home/trainee/training/f4'
'/home/trainee/training/f5' -> './home/trainee/training/f5'
'/home/trainee/training/f52' -> './home/trainee/training/f52'
'/home/trainee/training/f62' -> './home/trainee/training/f62'
'/home/trainee/training/a100' -> './home/trainee/training/a100'
'/home/trainee/training/f' -> './home/trainee/training/f'
'/home/trainee/training/f.txt' -> './home/trainee/training/f.txt'
'/home/trainee/training/f123.txt' -> './home/trainee/training/f123.txt'
'/home/trainee/training/f123123.txt' -> './home/trainee/training/f123123.txt'
'/home/trainee/training/f123123123.txt' -> './home/trainee/training/f123123123.txt'
'/home/trainee/training/file' -> './home/trainee/training/file'
'/home/trainee/training/user_check' -> './home/trainee/training/user_check'
'/home/trainee/codes' -> './home/trainee/codes'
'/home/trainee/codes/exit.txt' -> './home/trainee/codes/exit.txt'
'/home/fenestros2' -> './home/fenestros2'
'/home/fenestros2/.bash_logout' -> './home/fenestros2/.bash_logout'
'/home/fenestros2/.bash_history' -> './home/fenestros2/.bash_history'
'/home/fenestros2/.bash_profile' -> './home/fenestros2/.bash_profile'
'/home/fenestros2/.bashrc' -> './home/fenestros2/.bashrc'
'/home/fenestros1' -> './home/fenestros1'
'/home/fenestros1/.bash_logout' -> './home/fenestros1/.bash_logout'
'/home/fenestros1/.bash_profile' -> './home/fenestros1/.bash_profile'
'/home/fenestros1/.bashrc' -> './home/fenestros1/.bashrc'

Rsync ou Remote Sync est un utilitaire de synchronisation de fichiers qui utilise un algorithme qui minimise la quantité de données copiée en ne copiant que les parties des fichiers qui ont été modifiées.

Créez les répertoires /test/repA et mkdir /test/repB :

[root@centos8 ~]# mkdir -p /test/repA; mkdir /test/repB

Créez maintenant 20 fichiers vides dans le répertoire /test/repA :

[root@centos8 ~]# touch /test/repA/file{1..20}
[root@centos8 ~]# ls -l /test/repA/
total 0
-rw-r--r--. 1 root root 0 Jun  2 15:49 file1
-rw-r--r--. 1 root root 0 Jun  2 15:49 file10
-rw-r--r--. 1 root root 0 Jun  2 15:49 file11
-rw-r--r--. 1 root root 0 Jun  2 15:49 file12
-rw-r--r--. 1 root root 0 Jun  2 15:49 file13
-rw-r--r--. 1 root root 0 Jun  2 15:49 file14
-rw-r--r--. 1 root root 0 Jun  2 15:49 file15
-rw-r--r--. 1 root root 0 Jun  2 15:49 file16
-rw-r--r--. 1 root root 0 Jun  2 15:49 file17
-rw-r--r--. 1 root root 0 Jun  2 15:49 file18
-rw-r--r--. 1 root root 0 Jun  2 15:49 file19
-rw-r--r--. 1 root root 0 Jun  2 15:49 file2
-rw-r--r--. 1 root root 0 Jun  2 15:49 file20
-rw-r--r--. 1 root root 0 Jun  2 15:49 file3
-rw-r--r--. 1 root root 0 Jun  2 15:49 file4
-rw-r--r--. 1 root root 0 Jun  2 15:49 file5
-rw-r--r--. 1 root root 0 Jun  2 15:49 file6
-rw-r--r--. 1 root root 0 Jun  2 15:49 file7
-rw-r--r--. 1 root root 0 Jun  2 15:49 file8
-rw-r--r--. 1 root root 0 Jun  2 15:49 file9

Pout synchroniser les fichiers de /test/repA vers le répertoire /test/repB, utilisez l'option -r de la commande rsync :

[root@centos8 ~]# rsync -r /test/repA/ /test/repB
[root@centos8 ~]# ls -l /test/repB/
total 0
-rw-r--r--. 1 root root 0 Jun  2 15:50 file1
-rw-r--r--. 1 root root 0 Jun  2 15:50 file10
-rw-r--r--. 1 root root 0 Jun  2 15:50 file11
-rw-r--r--. 1 root root 0 Jun  2 15:50 file12
-rw-r--r--. 1 root root 0 Jun  2 15:50 file13
-rw-r--r--. 1 root root 0 Jun  2 15:50 file14
-rw-r--r--. 1 root root 0 Jun  2 15:50 file15
-rw-r--r--. 1 root root 0 Jun  2 15:50 file16
-rw-r--r--. 1 root root 0 Jun  2 15:50 file17
-rw-r--r--. 1 root root 0 Jun  2 15:50 file18
-rw-r--r--. 1 root root 0 Jun  2 15:50 file19
-rw-r--r--. 1 root root 0 Jun  2 15:50 file2
-rw-r--r--. 1 root root 0 Jun  2 15:50 file20
-rw-r--r--. 1 root root 0 Jun  2 15:50 file3
-rw-r--r--. 1 root root 0 Jun  2 15:50 file4
-rw-r--r--. 1 root root 0 Jun  2 15:50 file5
-rw-r--r--. 1 root root 0 Jun  2 15:50 file6
-rw-r--r--. 1 root root 0 Jun  2 15:50 file7
-rw-r--r--. 1 root root 0 Jun  2 15:50 file8
-rw-r--r--. 1 root root 0 Jun  2 15:50 file9

Supprimez les fichiers dans /test/repB :

[root@centos8 ~]# rm -rf /test/repB/*
[root@centos8 ~]# ls -l /test/repB/
total 0

Pour synchroniser les fichiers de /test/repA vers le répertoire /test/repB, utilisez l'option -a de la commande rsync :

[root@centos8 ~]# rsync -a /test/repA/ /test/repB
[root@centos8 ~]# ls -l /test/repB/
total 0
-rw-r--r--. 1 root root 0 Jun  2 15:49 file1
-rw-r--r--. 1 root root 0 Jun  2 15:49 file10
-rw-r--r--. 1 root root 0 Jun  2 15:49 file11
-rw-r--r--. 1 root root 0 Jun  2 15:49 file12
-rw-r--r--. 1 root root 0 Jun  2 15:49 file13
-rw-r--r--. 1 root root 0 Jun  2 15:49 file14
-rw-r--r--. 1 root root 0 Jun  2 15:49 file15
-rw-r--r--. 1 root root 0 Jun  2 15:49 file16
-rw-r--r--. 1 root root 0 Jun  2 15:49 file17
-rw-r--r--. 1 root root 0 Jun  2 15:49 file18
-rw-r--r--. 1 root root 0 Jun  2 15:49 file19
-rw-r--r--. 1 root root 0 Jun  2 15:49 file2
-rw-r--r--. 1 root root 0 Jun  2 15:49 file20
-rw-r--r--. 1 root root 0 Jun  2 15:49 file3
-rw-r--r--. 1 root root 0 Jun  2 15:49 file4
-rw-r--r--. 1 root root 0 Jun  2 15:49 file5
-rw-r--r--. 1 root root 0 Jun  2 15:49 file6
-rw-r--r--. 1 root root 0 Jun  2 15:49 file7
-rw-r--r--. 1 root root 0 Jun  2 15:49 file8
-rw-r--r--. 1 root root 0 Jun  2 15:49 file9

De nouveau, supprimez les fichiers dans le répertoire /test/repB :

[root@centos8 ~]# rm -rf /test/repB/*
[root@centos8 ~]# ls -l /test/repB/
total 0

Exécutez maintenant le commande suivante et constatez le résultat :

[root@centos8 ~]# rsync -a /test/repA /test/repB
[root@centos8 ~]# ls -l /test/repB/
total 0
drwxr-xr-x. 2 root root 277 Jun  2 15:49 repA
[root@centos8 ~]# ls -l /test/repB/repA
total 0
-rw-r--r--. 1 root root 0 Jun  2 15:49 file1
-rw-r--r--. 1 root root 0 Jun  2 15:49 file10
-rw-r--r--. 1 root root 0 Jun  2 15:49 file11
-rw-r--r--. 1 root root 0 Jun  2 15:49 file12
-rw-r--r--. 1 root root 0 Jun  2 15:49 file13
-rw-r--r--. 1 root root 0 Jun  2 15:49 file14
-rw-r--r--. 1 root root 0 Jun  2 15:49 file15
-rw-r--r--. 1 root root 0 Jun  2 15:49 file16
-rw-r--r--. 1 root root 0 Jun  2 15:49 file17
-rw-r--r--. 1 root root 0 Jun  2 15:49 file18
-rw-r--r--. 1 root root 0 Jun  2 15:49 file19
-rw-r--r--. 1 root root 0 Jun  2 15:49 file2
-rw-r--r--. 1 root root 0 Jun  2 15:49 file20
-rw-r--r--. 1 root root 0 Jun  2 15:49 file3
-rw-r--r--. 1 root root 0 Jun  2 15:49 file4
-rw-r--r--. 1 root root 0 Jun  2 15:49 file5
-rw-r--r--. 1 root root 0 Jun  2 15:49 file6
-rw-r--r--. 1 root root 0 Jun  2 15:49 file7
-rw-r--r--. 1 root root 0 Jun  2 15:49 file8
-rw-r--r--. 1 root root 0 Jun  2 15:49 file9

Pour éviter des erreurs, la commande rsync vous permet de visualiser le résultat de votre commande sans exécuter la commande grâce à l'utilisation des options -n et -r.

De nouveau, supprimez les fichiers dans le répertoire /test/repB :

[root@centos8 ~]# rm -rf /test/repB/*
[root@centos8 ~]# ls -l /test/repB/
total 0

Exécutez la commande ci-dessous :

[root@centos8 ~]# rsync -anv /test/repA/ /test/repB
sending incremental file list
./
file1
file10
file11
file12
file13
file14
file15
file16
file17
file18
file19
file2
file20
file3
file4
file5
file6
file7
file8
file9

sent 372 bytes  received 79 bytes  902.00 bytes/sec
total size is 0  speedup is 0.00 (DRY RUN)

Maintenant, exécutez la commande ci-dessous :

[root@centos8 ~]# rsync -anv /test/repA /test/repB
sending incremental file list
repA/
repA/file1
repA/file10
repA/file11
repA/file12
repA/file13
repA/file14
repA/file15
repA/file16
repA/file17
repA/file18
repA/file19
repA/file2
repA/file20
repA/file3
repA/file4
repA/file5
repA/file6
repA/file7
repA/file8
repA/file9

sent 385 bytes  received 80 bytes  930.00 bytes/sec
total size is 0  speedup is 0.00 (DRY RUN)

Les options de la commande rsync sont :

[root@centos8 ~]# rsync --help
rsync  version 3.1.3  protocol version 31
Copyright (C) 1996-2018 by Andrew Tridgell, Wayne Davison, and others.
Web site: http://rsync.samba.org/
Capabilities:
    64-bit files, 64-bit inums, 64-bit timestamps, 64-bit long ints,
    socketpairs, hardlinks, symlinks, IPv6, batchfiles, inplace,
    append, ACLs, xattrs, iconv, symtimes, prealloc

rsync comes with ABSOLUTELY NO WARRANTY.  This is free software, and you
are welcome to redistribute it under certain conditions.  See the GNU
General Public Licence for details.

rsync is a file transfer program capable of efficient remote update
via a fast differencing algorithm.

Usage: rsync [OPTION]... SRC [SRC]... DEST
  or   rsync [OPTION]... SRC [SRC]... [USER@]HOST:DEST
  or   rsync [OPTION]... SRC [SRC]... [USER@]HOST::DEST
  or   rsync [OPTION]... SRC [SRC]... rsync://[USER@]HOST[:PORT]/DEST
  or   rsync [OPTION]... [USER@]HOST:SRC [DEST]
  or   rsync [OPTION]... [USER@]HOST::SRC [DEST]
  or   rsync [OPTION]... rsync://[USER@]HOST[:PORT]/SRC [DEST]
The ':' usages connect via remote shell, while '::' & 'rsync://' usages connect
to an rsync daemon, and require SRC or DEST to start with a module name.

Options
 -v, --verbose               increase verbosity
     --info=FLAGS            fine-grained informational verbosity
     --debug=FLAGS           fine-grained debug verbosity
     --msgs2stderr           special output handling for debugging
 -q, --quiet                 suppress non-error messages
     --no-motd               suppress daemon-mode MOTD (see manpage caveat)
 -c, --checksum              skip based on checksum, not mod-time & size
 -a, --archive               archive mode; equals -rlptgoD (no -H,-A,-X)
     --no-OPTION             turn off an implied OPTION (e.g. --no-D)
 -r, --recursive             recurse into directories
 -R, --relative              use relative path names
     --no-implied-dirs       don't send implied dirs with --relative
 -b, --backup                make backups (see --suffix & --backup-dir)
     --backup-dir=DIR        make backups into hierarchy based in DIR
     --suffix=SUFFIX         set backup suffix (default ~ w/o --backup-dir)
 -u, --update                skip files that are newer on the receiver
     --inplace               update destination files in-place (SEE MAN PAGE)
     --append                append data onto shorter files
     --append-verify         like --append, but with old data in file checksum
 -d, --dirs                  transfer directories without recursing
 -l, --links                 copy symlinks as symlinks
 -L, --copy-links            transform symlink into referent file/dir
     --copy-unsafe-links     only "unsafe" symlinks are transformed
     --safe-links            ignore symlinks that point outside the source tree
     --munge-links           munge symlinks to make them safer (but unusable)
 -k, --copy-dirlinks         transform symlink to a dir into referent dir
 -K, --keep-dirlinks         treat symlinked dir on receiver as dir
 -H, --hard-links            preserve hard links
 -p, --perms                 preserve permissions
 -E, --executability         preserve the file's executability
     --chmod=CHMOD           affect file and/or directory permissions
 -A, --acls                  preserve ACLs (implies --perms)
 -X, --xattrs                preserve extended attributes
 -o, --owner                 preserve owner (super-user only)
 -g, --group                 preserve group
     --devices               preserve device files (super-user only)
     --copy-devices          copy device contents as regular file
     --specials              preserve special files
 -D                          same as --devices --specials
 -t, --times                 preserve modification times
 -O, --omit-dir-times        omit directories from --times
 -J, --omit-link-times       omit symlinks from --times
     --super                 receiver attempts super-user activities
     --fake-super            store/recover privileged attrs using xattrs
 -S, --sparse                turn sequences of nulls into sparse blocks
     --preallocate           allocate dest files before writing them
 -n, --dry-run               perform a trial run with no changes made
 -W, --whole-file            copy files whole (without delta-xfer algorithm)
     --checksum-choice=STR   choose the checksum algorithms
 -x, --one-file-system       don't cross filesystem boundaries
 -B, --block-size=SIZE       force a fixed checksum block-size
 -e, --rsh=COMMAND           specify the remote shell to use
     --rsync-path=PROGRAM    specify the rsync to run on the remote machine
     --existing              skip creating new files on receiver
     --ignore-existing       skip updating files that already exist on receiver
     --remove-source-files   sender removes synchronized files (non-dirs)
     --del                   an alias for --delete-during
     --delete                delete extraneous files from destination dirs
     --delete-before         receiver deletes before transfer, not during
     --delete-during         receiver deletes during the transfer
     --delete-delay          find deletions during, delete after
     --delete-after          receiver deletes after transfer, not during
     --delete-excluded       also delete excluded files from destination dirs
     --ignore-missing-args   ignore missing source args without error
     --delete-missing-args   delete missing source args from destination
     --ignore-errors         delete even if there are I/O errors
     --force                 force deletion of directories even if not empty
     --max-delete=NUM        don't delete more than NUM files
     --max-size=SIZE         don't transfer any file larger than SIZE
     --min-size=SIZE         don't transfer any file smaller than SIZE
     --partial               keep partially transferred files
     --partial-dir=DIR       put a partially transferred file into DIR
     --delay-updates         put all updated files into place at transfer's end
 -m, --prune-empty-dirs      prune empty directory chains from the file-list
     --numeric-ids           don't map uid/gid values by user/group name
     --usermap=STRING        custom username mapping
     --groupmap=STRING       custom groupname mapping
     --chown=USER:GROUP      simple username/groupname mapping
     --timeout=SECONDS       set I/O timeout in seconds
     --contimeout=SECONDS    set daemon connection timeout in seconds
 -I, --ignore-times          don't skip files that match in size and mod-time
 -M, --remote-option=OPTION  send OPTION to the remote side only
     --size-only             skip files that match in size
 -@, --modify-window=NUM     set the accuracy for mod-time comparisons
 -T, --temp-dir=DIR          create temporary files in directory DIR
 -y, --fuzzy                 find similar file for basis if no dest file
     --compare-dest=DIR      also compare destination files relative to DIR
     --copy-dest=DIR         ... and include copies of unchanged files
     --link-dest=DIR         hardlink to files in DIR when unchanged
 -z, --compress              compress file data during the transfer
     --compress-level=NUM    explicitly set compression level
     --skip-compress=LIST    skip compressing files with a suffix in LIST
 -C, --cvs-exclude           auto-ignore files the same way CVS does
 -f, --filter=RULE           add a file-filtering RULE
 -F                          same as --filter='dir-merge /.rsync-filter'
                             repeated: --filter='- .rsync-filter'
     --exclude=PATTERN       exclude files matching PATTERN
     --exclude-from=FILE     read exclude patterns from FILE
     --include=PATTERN       don't exclude files matching PATTERN
     --include-from=FILE     read include patterns from FILE
     --files-from=FILE       read list of source-file names from FILE
 -0, --from0                 all *-from/filter files are delimited by 0s
 -s, --protect-args          no space-splitting; only wildcard special-chars
     --address=ADDRESS       bind address for outgoing socket to daemon
     --port=PORT             specify double-colon alternate port number
     --sockopts=OPTIONS      specify custom TCP options
     --blocking-io           use blocking I/O for the remote shell
     --stats                 give some file-transfer stats
 -8, --8-bit-output          leave high-bit chars unescaped in output
 -h, --human-readable        output numbers in a human-readable format
     --progress              show progress during transfer
 -P                          same as --partial --progress
 -i, --itemize-changes       output a change-summary for all updates
     --out-format=FORMAT     output updates using the specified FORMAT
     --log-file=FILE         log what we're doing to the specified FILE
     --log-file-format=FMT   log updates using the specified FMT
     --password-file=FILE    read daemon-access password from FILE
     --list-only             list the files instead of copying them
     --bwlimit=RATE          limit socket I/O bandwidth
     --outbuf=N|L|B          set output buffering to None, Line, or Block
     --write-batch=FILE      write a batched update to FILE
     --only-write-batch=FILE like --write-batch but w/o updating destination
     --read-batch=FILE       read a batched update from FILE
     --protocol=NUM          force an older protocol version to be used
     --iconv=CONVERT_SPEC    request charset conversion of filenames
     --checksum-seed=NUM     set block/file checksum seed (advanced)
 -4, --ipv4                  prefer IPv4
 -6, --ipv6                  prefer IPv6
     --version               print version number
(-h) --help                  show this help (-h is --help only if used alone)

Use "rsync --daemon --help" to see the daemon-mode command-line options.
Please see the rsync(1) and rsyncd.conf(5) man pages for full documentation.
See http://rsync.samba.org/ for updates, bug reports, and answers

La commande gzip est un utilitaire de compression sous GNU/Linux. La commande gunzip est un utilitaire de décompression sous GNU/Linux.

Les options de la commande gzip sont :

[root@centos8 /]# gzip --help
Usage: gzip [OPTION]... [FILE]...
Compress or uncompress FILEs (by default, compress FILES in-place).

Mandatory arguments to long options are mandatory for short options too.

  -c, --stdout      write on standard output, keep original files unchanged
  -d, --decompress  decompress
  -f, --force       force overwrite of output file and compress links
  -h, --help        give this help
  -k, --keep        keep (don't delete) input files
  -l, --list        list compressed file contents
  -L, --license     display software license
  -n, --no-name     do not save or restore the original name and timestamp
  -N, --name        save or restore the original name and timestamp
  -q, --quiet       suppress all warnings
  -r, --recursive   operate recursively on directories
      --rsyncable   make rsync-friendly archive
  -S, --suffix=SUF  use suffix SUF on compressed files
      --synchronous synchronous output (safer if system crashes, but slower)
  -t, --test        test compressed file integrity
  -v, --verbose     verbose mode
  -V, --version     display version number
  -1, --fast        compress faster
  -9, --best        compress better

With no FILE, or when FILE is -, read standard input.

Report bugs to <bug-gzip@gnu.org>.

Les options de la commande gunzip sont :

[root@centos8 /]# gunzip --help
Usage: /usr/bin/gunzip [OPTION]... [FILE]...
Uncompress FILEs (by default, in-place).

Mandatory arguments to long options are mandatory for short options too.

  -c, --stdout      write on standard output, keep original files unchanged
  -f, --force       force overwrite of output file and compress links
  -k, --keep        keep (don't delete) input files
  -l, --list        list compressed file contents
  -n, --no-name     do not save or restore the original name and timestamp
  -N, --name        save or restore the original name and timestamp
  -q, --quiet       suppress all warnings
  -r, --recursive   operate recursively on directories
  -S, --suffix=SUF  use suffix SUF on compressed files
      --synchronous synchronous output (safer if system crashes, but slower)
  -t, --test        test compressed file integrity
  -v, --verbose     verbose mode
      --help        display this help and exit
      --version     display version information and exit

With no FILE, or when FILE is -, read standard input.

Report bugs to <bug-gzip@gnu.org>.

Utilisez gzip pour compresser votre fichier tar :

[root@centos8 /]# gzip /tmp/test.tar

Constatez la taille du fichier test.tar.gz :

[root@centos8 /]# ls -l /tmp/test.tar.gz
-rw-r--r--. 1 root root 218 Jun  2 14:07 /tmp/test.tar.gz

Décompressez le fichier test.tar.gz :

[root@centos8 /]# gunzip /tmp/test.tar.gz 

La commande bzip2 est un utilitaire de compression sous GNU/Linux. La commande bunzip2 est un utilitaire de décompression sous GNU/Linux.

Les options de la commande bzip2 sont :

[root@centos8 /]# bzip2 --help
bzip2, a block-sorting file compressor.  Version 1.0.6, 6-Sept-2010.

   usage: bzip2 [flags and input files in any order]

   -h --help           print this message
   -d --decompress     force decompression
   -z --compress       force compression
   -k --keep           keep (don't delete) input files
   -f --force          overwrite existing output files
   -t --test           test compressed file integrity
   -c --stdout         output to standard out
   -q --quiet          suppress noncritical error messages
   -v --verbose        be verbose (a 2nd -v gives more)
   -L --license        display software version & license
   -V --version        display software version & license
   -s --small          use less memory (at most 2500k)
   -1 .. -9            set block size to 100k .. 900k
   --fast              alias for -1
   --best              alias for -9

   If invoked as `bzip2', default action is to compress.
              as `bunzip2',  default action is to decompress.
              as `bzcat', default action is to decompress to stdout.

   If no file names are given, bzip2 compresses or decompresses
   from standard input to standard output.  You can combine
   short flags, so `-v -4' means the same as -v4 or -4v, &c.

Les options de la commande bunzip2 sont :

[root@centos8 /]# bunzip2 --help
bzip2, a block-sorting file compressor.  Version 1.0.6, 6-Sept-2010.

   usage: bunzip2 [flags and input files in any order]

   -h --help           print this message
   -d --decompress     force decompression
   -z --compress       force compression
   -k --keep           keep (don't delete) input files
   -f --force          overwrite existing output files
   -t --test           test compressed file integrity
   -c --stdout         output to standard out
   -q --quiet          suppress noncritical error messages
   -v --verbose        be verbose (a 2nd -v gives more)
   -L --license        display software version & license
   -V --version        display software version & license
   -s --small          use less memory (at most 2500k)
   -1 .. -9            set block size to 100k .. 900k
   --fast              alias for -1
   --best              alias for -9

   If invoked as `bzip2', default action is to compress.
              as `bunzip2',  default action is to decompress.
              as `bzcat', default action is to decompress to stdout.

   If no file names are given, bzip2 compresses or decompresses
   from standard input to standard output.  You can combine
   short flags, so `-v -4' means the same as -v4 or -4v, &c.

Utilisez bzip2 pour compresser votre fichier tar :

[root@centos8 /]# bzip2 /tmp/test.tar

Constatez la taille du fichier tar.bz2 :

[root@centos8 /]# ls -l /tmp | grep test.tar.bz
-rw-r--r--. 1 root root    206 Jun  2 14:07 test.tar.bz2

Décompressez le fichier tar.bz2 :

[root@centos8 /]# bunzip2 /tmp/test.tar.bz2

La commande xz est un utilitaire de compression sous GNU/Linux. D'autres commandes sont :

• unxz - équivalent à xz –decompress.
• xzcat - équivalent à xz –decompress –stdout.
• lzma - équivalent à xz –format=lzma.
• unlzma - équivalent à xz –format=lzma –decompress.
• lzcat - équivalent à xz –format=lzma –decompress –stdout.

La commande xz ne compressera pas le fichier si :

• le fichier n'est pas de type standard
• le fichier est un lien symbolique
• le fichier est un lien physique
• le fichier possède le sticky bit, le SUID bit ou le SGID bit
• le fichier possède déjà une extension .xz ou .lzma

La commande xz ne décompressera pas le fichier si :

• le fichier ne possède pas d'extension .xz ou .lzma

Les options de la commande xz sont :

[root@centos8 /]# xz --help
Usage: xz [OPTION]... [FILE]...
Compress or decompress FILEs in the .xz format.

  -z, --compress      force compression
  -d, --decompress    force decompression
  -t, --test          test compressed file integrity
  -l, --list          list information about .xz files
  -k, --keep          keep (don't delete) input files
  -f, --force         force overwrite of output file and (de)compress links
  -c, --stdout        write to standard output and don't delete input files
  -0 ... -9           compression preset; default is 6; take compressor *and*
                      decompressor memory usage into account before using 7-9!
  -e, --extreme       try to improve compression ratio by using more CPU time;
                      does not affect decompressor memory requirements
  -T, --threads=NUM   use at most NUM threads; the default is 1; set to 0
                      to use as many threads as there are processor cores
  -q, --quiet         suppress warnings; specify twice to suppress errors too
  -v, --verbose       be verbose; specify twice for even more verbose
  -h, --help          display this short help and exit
  -H, --long-help     display the long help (lists also the advanced options)
  -V, --version       display the version number and exit

With no FILE, or when FILE is -, read standard input.

Report bugs to <lasse.collin@tukaani.org> (in English or Finnish).
XZ Utils home page: <https://tukaani.org/xz/>

Utilisez xz pour compresser votre fichier tar :

[root@centos8 /]# xz /tmp/test.tar 

Constatez la présence du fichier test.tar.xz :

[root@centos8 /]# ls -l /tmp | grep test.tar.xz
-rw-r--r--. 1 root root    228 Jun  2 14:07 test.tar.xz

Décompressez le fichier test.tar.xz :

[root@centos8 /]# xz -d /tmp/test.tar.xz
[root@centos8 /]# ls -l /tmp | grep test
-rw-r--r--. 1 root root    512 Jun  2 14:15 test.cpio
-rw-r--r--. 1 root root  10240 Jun  2 14:07 test.tar

Il existe d'autres utilitaires pour la compression, chacun produisant un fichier ayant une extension spécifique :

<html> <div align=“center”> Copyright © 2021 Hugh Norris. </html>