Mirrored with Versioning

[Leonid Feldman]

HI all,

Is there a method for creating a mirrored set with versioning in ZFS with only 2 drives?
In other words, is it possible to have a live bootable volume on 1 drive with a redundant bootable volume on another larger drive that also retains versions/snapshots?

Thanks in advance,

Tyr

 

[junovitch@]

You can do a mirror but you would only get the capacity of the smallest drive. Both drives can have boot code and be mirrors of each other. If you create a freebsd-zfs partition of the same size you should have no issues creating a mirror of both drives. If you don't, as shown below with a file backed pool, you will get an error but you can force creation of the pool anyway with the result being the smaller size as mentioned.

# truncate -s 5g /tmp/5g
# truncate -s 10g /tmp/10g
# zpool create filebacked mirror /tmp/5g /tmp/10g

invalid vdev specification
use '-f' to override the following errors:
mirror contains devices of different sizes

# zpool create -f filebacked mirror /tmp/5g /tmp/10g
# zfs list | grep filebacked

filebacked  56.5K  4.81G  19K  /filebacked