FreeBSD ZFS catching mismatched disks

Software

I was creating a ZFS mirrored pool on a FreeBSD cloud instance with two identical data disks, like a gentleman:

$ ovm create disk test1 in SY3 with 100g on tier SSD
$ ovm create disk test2 in SY3 with 10gb on tier SSD
$ ovm attach disk test1 to VM test
$ ovm attach disk test2 to VM test

And then on the VM:

# glabel test1 /dev/ada1
# glabel test2 /dev/ada2
# zpool create [options] mirror tank \
    /dev/label/test1 /dev/label/test2

Output:

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

Whoops! Turns out they were less identical than I realised. You’ve have thought the monospace font not lining up during provisioning would have been a clue. Either way, good to know. Also, derp.

Author bio and support

Me!

Ruben Schade is a technical writer and infrastructure architect in Sydney, Australia who refers to himself in the third person in bios. Hi!

The site is powered by Hugo, FreeBSD, and OpenZFS on OrionVM, everyone’s favourite bespoke cloud infrastructure provider.

If you found this post helpful or entertaining, you can shout me a coffee or send a comment. Thanks ☺️.