expanding a volume via backup recreate and restore

[pjr_atl]

I have an existing 3 x 2TB zfs volume I wish to expand to a 5 X 2 TB volume. I know there is no direct way to simply add drives to the pool (yes I could create another vdev and add that way but I would lose 2 TB of storage or have a high risk array.)

So my thought was backup existing pool, destroying existing pool, create new bigger pool, restore pool.

My hang up is whats the best way to backup and restore a zfs pool preserving everything? Can I hang a USB drive off the system and backup and restore from that if so how?

Thanks in advance this seems elementary and I did a lot of googling before posting here looking for a solution

 

[ben]

If you have another zfs capable system (FreeNAS, FreeBSD or whatever), you can send a snapshot of your filesystem to it and then later send it back to the new pool. Make sure to test a full round trip before relying on it for your irreplaceable data, though.

 

[pjr_atl]

unfortunately I don't have another system is there a way to do a local replication?

 

[ben]

The other automated way to do this would be rsync, which requires another computer that can run rsync but doesn't require ZFS. If that's not an option, and all you can do is direct-attach a drive... then sure, attach a drive, make it into a UFS volume, and copy the files over manually. The 'cp' command at the shell is likely what you'll end up using to copy stuff over. Once again, be super freaking sure you can get your data off again later.

 

[JaimieV]

You can send a local replica (ie to a second local ZFS volume) from the command line, but not from the GUI so far as I can see. Same last sentence as Ben's!

 

[pjr_atl]

discovered the following http://docs.oracle.com/cd/E19963-01/html/821-1448/gbchx.html#gbscu
using

zfs send zfs1@auto-20130106.0802-2w > /mnt/uback/data

which sends that snapshot to a data file

next step will be ringing it back with

zfs receive zfs1@auto-20130106.0802-2w < /mnt/uback/data

I think!

 

[ben]

Try a round of actually restoring from that, or you don't actually have a backup.