ZFS kernel panic in 21.05

[danderson]

Describe the bug

My NAS runs 21.05.20210721.63ee5cd (Okapi), with the stable ZFS package (version 2.0.5-1). Yesterday, it kernel-panicked in ZFS block management code.

I traced the panic back to openzfs/zfs#11531, which was fixed by openzfs/zfs@a81b812 and released in ZFS 2.1.0, but not backported to 2.0.x.

I filed openzfs/zfs#12494 to request a backport + 2.0.6 release upstream, so that downstream distros can pull the fix without having to upgrade a stable OS release to ZFS 2.1. I have no idea if the OpenZFS project continues maintaining prior minor releases for a while, or if they'll say that downstream distros should import the patch if they care.

Filing this bug to track either importing ZFS 2.0.6 if such a release happens, or to consider backporting the panic fix into NixOS as a downstream patch on 2.0.5.

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
  - linuxPackages.zfs
  - linuxPackages.zfsStable
# a list of nixos modules affected by the problem
module:

[danderson]

For reference: openzfs/zfs#12346 is a PR that backports two critical fixes (the crash mentioned above, and a persistent data corruption bug) for a prospective 2.0.6. It's not clear yet whether a 2.0.6 will actually happen, but that's the current upstream status.

[Ma27]

FYI zfsUnstable on 21.05 points to a stable ZFS 2.1, so if you can upgrade to a newer ZFS, but want to remain on a stable NixOS, that might be a workaround for you.

[danderson]

Sure, but that's adopting a major new release of ZFS on a stable storage system. I'd be much happier with a targeted fix against a more mature release. For this particular dataset, I don't want to be the first to find the exciting new 2.1 bugs :)

[Ma27]

Perfectly understandable & reasonable, just wanted to make sure you're aware of this option :)

[stale]

I marked this as stale due to inactivity. → More info

[SuperSandro2000]

21.05 is EOL