Comment by cesarb
2 months ago
> Btrfs [...] still doesn't match ZFS in features [...]
Isn't the feature in question (array expansion) precisely one which btrfs already had for a long time? Does ZFS have the opposite feature (shrinking the array), which AFAIK btrfs also already had for a long time?
(And there's one feature which is important to many, "being in the upstream Linux kernel", that ZFS most likely will never have.)
ZFS also had expansion for a long time but it was offline expansion. I don't know if btrfs has also had online for a long time?
And shrinking no, that is a big missing feature in ZFS IMO. Understandable considering its heritage (large scale datacenters) but nevertheless an issue for home use.
But raidz is rock-solid. Btrfs' raid is not.
Raidz wasn't able to be expanded in place before this. You were able to add to a pool that included a raidz vdev, but that raidz vdev was immutable.
Oh ok, I've never done this, but I thought it was already there. Maybe this was the original ZFS from Sun? But maybe I just remember it incorrectly, sorry.
I've used it on multi-drive arrays but I never had the need for expansion.
1 reply →
You can online expand a ZFS pool for years by replacing disks with larger ones or by adding vdevs. On current OpenZFS you can even expand a Raid-Z by adding disks to it.
To shrink a pool, you can remove vdevs. On OpenZFS this is limited to mirror vdevs, native ZFS from Oracle can remove Raid-Z.
Kernel integration is not so important as long as use distributions that include ZFS support at distribution level mainly Proxmox and TrueNAS or Ubuntu.