#####Use zbackup only for zfs versions, where next bugs are closed: openzfs/zfs#2652

openzfs/zfs#2656

###zbackup

zbackup is a multithreading zfs backuping (via snapshots) tool

###Installation: from sources:

go get github.com/theairkit/runcmd
go get github.com/theairkit/zfs
git clone github.com/theairkit/zbackup .
go install

for archlinux users there are PKGBUILD file:

git clone https://github.com/theairkit/zbackup.git
cd zbackup
git checkout pkgbuild-github
makepkg

###Description and examples

####zbackup can run in two modes: #####command-line mode: in this mode zbackup perform backup filesystems, which have a user-defined zfs-property with value 'true' (colon in property name is part of his name; this is zfs naming scheme for user-properties)

zfs list -H -o name,someprop: zroot/owl                 
zroot/owl   -

zfs set someprop:=true zroot/owl
zfs list -H -o name,someprop: zroot/owl
zroot/owl   true

after setting this property to fs, you can run zbackup:

zbackup -u zbackup: --host 192.186.20.80 --user root --key /root/.ssh/id_rsa

#####configuration-file mode: in this mode zbackup performs backup filsystem, described in config file ('-c' key)

configuration file have a TOML format and very simple:

cat /etc/zbackup/zbackup.conf

user           = "root"
host           = "192.168.20.80:22"
key            = "/root/.ssh/id_rsa"
max_io_threads = 1

[[backup]]
recursive      = true
expire_hours   = "1h"
local          = "zroot/src"
remote_root    = "zroot"
...
[[backup]]
...
[[backup]]

In remote_root you can specify:

• zfs pool name;
• zfs fs name: if not exists, zbackup will try to create it;

after creating configuration file, check config, start dry-run, and then perform zbackup:

zbackup -c /etc/zbackup/zbackup.conf -t
14:53:45.955870 9892 INFO config ok

zbackup -c /etc/zbackup/zbackup.conf --dry-run
14:54:14.052290 9900 INFO --dry-run set, only show backup tasks:
14:54:14.052345 9900 INFO zroot/src -> 192.168.20.80:22 zroot/owl-zroot-src
14:54:14.052357 9900 INFO zroot/src/blah -> 192.168.20.80:22 zroot/owl-zroot-src-blah
14:54:14.052366 9900 INFO zroot/src/host1 -> 192.168.20.80:22 zroot/owl-zroot-src-host1

zbackup -c /etc/zbackup/zbackup.conf -v debug
14:56:16.782904 9951 INFO [0]: starting backup
... log messages ...
14:56:17.973803 9951 INFO [2]: backup done

All command keys (some of them has a default values):

zbackup -h
Usage:
  zbackup -h
  zbackup --version
  zbackup [-c config]    [-t] [--dry-run] [-p pidfile] [-v loglevel] [-f logfile]
  zbackup -u zfsproperty [-t] [--dry-run] [-p pidfile] [-v loglevel] [-f logfile]
  --host host [--user user] [--key key] [--iothreads num] [--remote fs] [--expire hours]

Options:
  -h               this help
  --version        show version and exit
  -c config        configuration-based backup [default: /etc/zbackup/zbackup.conf]
  -t               test configuration and exit
  --dry-run        show fs will be backup and exit
  -p pidfile       set pidfile [default: /var/run/zbackup.pid]
  -v loglevel      set loglevel: info, debug [default: info]
  -f logfile       set logfile [default: stderr]
  -u zfsproperty   property-based backup
  --host host      set backup host ${hostname}:${port}
  --user user      set backup user [default: root]
  --key key        set keyfile [default: /root/.ssh/id_rsa]
  --iothreads num  set max parallel tasks [default: 1]
  --remote fs      set remote root fs [default: 'zroot']
  --expire hours   set expire time in hours or 'lastone' [default: 24h]

####Some internals

• zbackup parse config (or command-linme options) and create backup tasks
• based on max iothreads option, run this tasks in parallel

For every backup task:

• check for local fs snapshot with name: 'fs@zbackup_curr'

• if snapshot not exists - assume, that we run first time:

• create snapshot 'fs@zbackup_curr'

• local: zfs send fs@zbackup_curr

• remote: zfs recv $remote_root/$local_root-$fs@timestamp

• set 'readonly=on' for remote fs

• set 'zbackup: true' for remote snapshot

• if 'fs@zbackup_curr' exists:

• create snapshot 'fs@zbackup_new'

• local: zfs send -i fs@zbackup_new fs@zbackup@curr

• remote: zfs recv zfs recv $remote_root/$local_root-$fs@timestamp

• set 'zbackup: true' for remote snapshot

• run cleanup:

• by 'lastone': delete all remote snapshots with 'zbackup=true' for this fs, except last one

• by expire time: delete all remote snapshots, which created ealry that expire

• rotate local snapshots:

• delete local:'fs@zbackup_curr'

• rename local:'fs@zbackup_new' to 'fs@zbackup_curr'