Разница между amgtar и GNUTAR

У нас есть несколько сотен систем, выполняющих резервное копирование в ленточную библиотеку с помощью AMANDA. Каждый день мы получаем электронное письмо с длинным списком СТРАННЫХ результатов резервного копирования. Почти все это связано с тем, что на веб-сервере выполнялась запись файла журнала или обновлялся файловый кеш. Например (5 машин показывают разные СТРАННЫЕ сообщения):

STRANGE DUMP DETAILS:
  /-- av1 / lev 2 STRANGE
  sendbackup: start [avion:/ level 2]
  sendbackup: info BACKUP=/bin/tar
  sendbackup: info RECOVER_CMD=/bin/tar -xpGf - ...
  sendbackup: info end
  ? /bin/tar: ./boot: directory is on a different filesystem; not dumped
  ? /bin/tar: ./dev: directory is on a different filesystem; not dumped
  ? /bin/tar: ./fs: directory is on a different filesystem; not dumped
  ? /bin/tar: ./proc: directory is on a different filesystem; not dumped
  ? /bin/tar: ./run: directory is on a different filesystem; not dumped
  ? /bin/tar: ./sys: directory is on a different filesystem; not dumped
  ? /bin/tar: ./wwwusers: directory is on a different filesystem; not dumped
  | /bin/tar: ./tmp/.X11-unix/X0: socket ignored
  | /bin/tar: ./tmp/gpg-v9zbWU/S.gpg-agent: socket ignored
  | Total bytes written: 795084800 (759MiB, 740KiB/s)
  sendbackup: size 776450
  sendbackup: end
  \--------
  /-- gitlab / lev 3 STRANGE
  sendbackup: start [gitlab:/ level 3]
  sendbackup: info BACKUP=/bin/tar
  sendbackup: info RECOVER_CMD=/bin/tar -xpGf - ...
  sendbackup: info end
  | /bin/tar: ./tmp/gitaly-ruby215330643/socket.0: socket ignored
  | /bin/tar: ./tmp/gitaly-ruby215330643/socket.1: socket ignored
  | /bin/tar: ./var/lib/gssproxy/default.sock: socket ignored
  ? /bin/tar: ./var/log/gitlab/gitlab-workhorse/current: file changed as we read it
  ? /bin/tar: ./var/log/gitlab/nginx/gitlab_access.log: file changed as we read it
  | /bin/tar: ./var/opt/gitlab/gitaly/gitaly.socket: socket ignored
  | /bin/tar: ./var/opt/gitlab/gitlab-rails/sockets/gitlab.socket: socket ignored
  | /bin/tar: ./var/opt/gitlab/gitlab-workhorse/socket: socket ignored
  | /bin/tar: ./var/opt/gitlab/postgresql/.s.PGSQL.5432: socket ignored
  | /bin/tar: ./var/opt/gitlab/redis/redis.socket: socket ignored
  | /bin/tar: ./var/spool/postfix/private/anvil: socket ignored
  | /bin/tar: ./var/spool/postfix/private/bounce: socket ignored
  | /bin/tar: ./var/spool/postfix/private/defer: socket ignored
  | /bin/tar: ./var/spool/postfix/private/discard: socket ignored
  | /bin/tar: ./var/spool/postfix/private/error: socket ignored
  | /bin/tar: ./var/spool/postfix/private/lmtp: socket ignored
  Look in the '/var/log/amanda/log.error/gitlab._.3.20180606231049.errout' file for full error messages
  \--------
  /-- haproxy00-127 / lev 3 STRANGE
  sendbackup: start [haproxy00-127:/ level 3]
  sendbackup: info BACKUP=/bin/tar
  sendbackup: info RECOVER_CMD=/bin/tar -xpGf - ...
  sendbackup: info end
  ? /bin/tar: ./var/log/messages: file changed as we read it
  Look in the '/var/log/amanda/log.error/haproxy00-127._.3.20180607003248.errout' file for full error messages
  \--------
  /-- imap00 /srv/dovecot lev 0 STRANGE
  sendbackup: start [imap00:/srv/dovecot level 0]
  sendbackup: info BACKUP=/bin/tar
  sendbackup: info RECOVER_CMD=/bin/tar -xpGf - ...
  sendbackup: info end
  ? /bin/tar: ./a1/Maildir/new/1528332018.M.imap00.example.com,S=6309,W=6430: File removed before we read it
  ? /bin/tar: ./a1/Maildir/new/1528335571.M.imap00.example.com,S=8299,W=8451: File removed before we read it
  ? /bin/tar: ./a2/Maildir/cur/1528306776.M.imap00.example.com,S=13517,W=13770\:2,Scd: File removed before we read it
  ? /bin/tar: ./a2/Maildir/cur/1528332257.M.imap00.example.com,S=22257,W=22562\:2,STcd: File removed before we read it
  ? /bin/tar: ./a3/Maildir/cur/1528287062.M.imap00.example.com,S=10343,W=10558\:2,: File removed before we read it
  ? /bin/tar: ./a3/Maildir/cur/1528297383.M.imap00.example.com,S=4179,W=4265\:2,: File removed before we read it
  ? /bin/tar: ./a3/Maildir/cur/1528312816.M.imap00.example.com,S=29364,W=29796\:2,: File removed before we read it
  ? /bin/tar: ./a3/Maildir/new/1528327304.M.imap00.example.com,S=52059,W=53029: File removed before we read it
  ? /bin/tar: ./a4/Maildir/.folder/dovecot.index.log.2: File removed before we read it
  ? /bin/tar: ./a4/Maildir/.Personal/dovecot.index.log.2: File removed before we read it
  ? /bin/tar: ./a4/Maildir/.Trash/cur/1527783480.M.imap00.example.com,S=31976,W=32433\:2,Sab: File removed before we read it
  ? /bin/tar: ./a4/Maildir/cur/1528336066.M.imap00.example.com,S=122100,W=124740\:2,ab: File removed before we read it
  ? /bin/tar: ./a4/Maildir/cur/1528337059.M.imap00.example.com,S=28553,W=28964\:2,ab: File removed before we read it
  Look in the '/var/log/amanda/log.error/imap00._srv_dovecot.0.20180606220538.errout' file for full error messages
  \--------
  /-- webserver1 / lev 2 STRANGE
  sendbackup: start [webserver1:/ level 2]
  sendbackup: info BACKUP=/bin/tar
  sendbackup: info RECOVER_CMD=/bin/tar -xpGf - ...
  sendbackup: info end
  ? /bin/tar: ./var/log/httpd/kemp_access_log: file changed as we read it
  ? /bin/tar: ./var/log/httpd/wiki.example.com_access_ssl.log: file changed as we read it
  ? /bin/tar: ./var/log/httpd/www.example.com_access.log: file changed as we read it
  ? /bin/tar: ./var/log/httpd/www.example.com_ssl_access_ssl.log: file changed as we read it
  Look in the '/var/log/amanda/log.error/webserver1._.2.20180607004437.errout' file for full error messages
  \--------

(brought to you by Amanda version 3.3.3)

Соответствующие части нашей текущей конфигурации:

define dumptype nocomp-root-tar {
    program "GNUTAR"
    comment "Root partitions with gtar"
    compress none
    estimate server
    priority low
    exclude list "/etc/amanda/amanda.exclude.list"
    auth "bsd"
}
define dumptype nocomp-user-tar {
    program "GNUTAR"
    comment "Non-root partitions with gtar"
    compress none
    estimate server
    priority medium
    exclude list "/etc/amanda/amanda.exclude.list"
    auth "bsd"
}

Мы не хотим исключать эти файлы из резервной копии только потому, что они могут измениться или исчезнуть. Мы также не можем отключить сервер IMAP во время резервного копирования. Похоже, я могу изменить наши системы, чтобы использовать amgtar как их метод резервного копирования, который позволит нам устранить все эти сообщения.

define application-tool app_amgtar {
    plugin "amgtar"

    property        "NORMAL" ": socket ignored$"
    property append "NORMAL" "file changed as we read it$"
    property append "NORMAL" ": directory is on a different filesystem; not dumped$"
    property append "NORMAL" ": File removed before we read it$"

}
define dumptype nocomp-root-amgtar {
    program "APPLICATION"
    application "app_amgtar"
    comment "Root partitions with amgtar"
    compress none
    estimate server
    priority low
    exclude list "/etc/amanda/amanda.exclude.list"
    auth "bsd"
}
...

Есть ли у amgtar?

Будет ли труднее восстановить старые резервные копии, если мы внесем это изменение?

В документации, кажется, говорится, что только GNUTAR поддерживает exclude list. Делает amgtar также поддерживают его, поскольку он использует GNUTAR под?