The existing system: I have a FreeBSD based backup/archive server, which pulls the backups from the live servers via rsync every night and does a zfs snapshot to archive the backup contents for a specific time.

This results in the situation, that on this server there are lots of ...

  • ... rsync tasks,
  • ... storage pools (one for every backup task the server fullfills),
  • ... snapshot tasks on that pools with different creation rules (from every 5 minutes to daily) and different retention times (from 3 days to 5 years),
  • ... already existing snapshots (~8k).

The task I want to accomplish now:

I want to build a offsite server that is a perfect mirror of this backup server and which is syncing daily with the above described system.

The Problem:

I haven't found any solution yet, which lets me easily sync the whole server / zfs filesystem including all snapshots. I only know that you can send a single snapshot to a remote zfs filesystem via zfs send. Obviously it would be great to not have to recreate the complex pool & snapshot structure on the offsite server because I feel this would be a total mess maintenance wise.

Is there any solution which allows to mirror a complete zfs filesystem including snapshots?

  1. option - when you want to stay with FreeBSD, check FreeNAS to automate complexity you are afraid of.
  2. option - NexentaStor, it is Solaris based storage appliance SW with great management web gui. Up to 18TB setup is for free. Again there you can easily manage complex zfs send|receive vs. a lot of datasets configuration.

If you have speedy lines between sites you want to mirror, I can imagine something like you export iSCSI volumes from sites storages and put them zpool mirror and add some local disks for ARC, ZIL, cache to lower read/write peaks running over iSCSI. If your storage is mainly for backups, then it would be OK. Nevertheless SUN once had such product behaving like that on ZFS.

  • 2
    Nobody uses Nexenta anymore! – ewwhite Nov 18 '14 at 11:42
  • Thank's for your answer, but could you elaborate a bit more how FreeNAS would help me with not having to configure everything twice? (BTW speed is not an issue at all, it's solely backup/archiving). – s1lv3r Nov 18 '14 at 11:45
  • @ewwhite somebody do, otherwise they are already bankrupt... ;-) But yes, for me personally NexentaStore is no benefit. I assume the same for you. – nudzo Nov 18 '14 at 12:11
  • 1
    ZFS replication does not fail gracefully (i.e. if one fails the whole pipeline gets jammed). I've had much better results with rsync and local snapshots. I'll use ZFS replication over a LAN, but nothing slower. – quadruplebucky Nov 18 '14 at 12:51
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    @nudzo if one of the rep snaps fails, the others won't proceed, and if you're looking for a "mirrored fs" (which the OP asked about and is not solvable within ZFS anyway) rsync comes much closer to success over WAN. – quadruplebucky Nov 18 '14 at 13:41

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