Send ZFS snapshots to external drive

[divB]

Hi,

As far as I know I can use 'zfs send' to send ZFS snapshots to a different machine.

I do not have a different machine but I will have an external harddisk connected over USB. Is it possible to backup snapshots of Zvols on such a harddisk (similar to zfs send)?

Regards
divB

 

[jgreco]

Sure, but you probably need to do it manually. "zfs send" doesn't really give a darn where it is sending to. You could create a ZFS pool on the external and then "zfs send" your snapshots onto it. This is essentially using your existing machine as the "different machine", but if you're not going to have your external disk connected and on 24/7, you probably don't want to try to make this work through the GUI. (I bet you could make it work through the GUI otherwise...) Other options exist for the creative folks.

 

[divB]

Oh, thank you, nice! So I guess this will work, e.g.:

Code:

zfs send -i plvl5i0/dsvz1szcs@backup-20120822 plvl5i0/dsvz1szcs@backup-20120823 | zfs recv usbdrive/dsvz1szcs

Maybe one question left: When plvl5i0 is 5TB and usbdrive 2TB, I can still send as many snapshots as long as the pure data blocks will fit onto usbdrive?

 

[jgreco]

More or less, since there's overhead to consider. It's also worth noting that with things like compression enabled, you might be able to stretch the 2TB a bit.