(user error, resolved)

[kingpalethe]

I previously was able to install ZFS on 22.04, and 24.04, and it seemed to work fine -- but recently if I do any software update on either of this LTS releases, ZFS fails completely -- when I try to run it, I get the Failed to initialize the libzfs library error. I think Canonical may have recently pushed an update which kills ZFS.

I've made multiple attempts to reinstall ZFS but have not yet succeeded.

As far as I can tell these directions are out of date: https://openzfs.github.io/openzfs-docs/Getting%20Started/Debian/index.html
-- I get a lot of error messages about PGP keys.

Previously I had used...

sudo apt install zfsutils-linux

But this installs version ZFS 2.2.2. It was working previously, but now that, after I reboot I get the Failed to initialize the libzfs library error, I realize that 2.2.2 is very old and not compatible Linux 6.8 kernel.

It also seems that Canonical have modified their installers going back to 22.04, such that it's not straightforward to install a version of Ubuntu that has an old enough kernel to be compatible with ZFS 2.2.2.

So -- I should try building from source, right?

I've tried starting here: https://zfsonlinux.org/ ... and starting from here: https://openzfs.github.io/openzfs-docs/Developer%20Resources/Building%20ZFS.html#configure-and-build .... all of these fail with multiple errors like

r rpc/xdr.h... no
configure: WARNING: cannot find tirpc via pkg-config or in the standard locations

I've also tried going to the "Ubuntu" installation instructions here: https://openzfs.github.io/openzfs-docs/Getting%20Started/Ubuntu/index.html

Which seem to push me back to 2.2.2.

Can anyone give me any hints for the best strategy to get ZFS working under Ubuntu?

I don't want to install it on my root boot disk or anything fancy -- I just want to set up a zpool mirror...

thanks!

[kingpalethe]

One thought I -- recently started adjusting the size of my ARC memory.... which I do by..

running this command....

sudo nano /etc/modprobe.d/zfs.conf

adding this line to zfs.conf .....

options zfs zfs_arc_max=options zfs zfs_arc_max=8589934592

and then running this command...

sudo update-initramfs -u

this last command produces the output
update-initramfs: Generating /boot/initrd.img-6.8.0-45-generic

After I do this, I reboot, and ZFS fails to load with the Failed to initialize the libzfs library error.

Should I just give up on this and assume there is no safe way to adjust any ZFS settings like this under Ubuntu?

DISCOVERY:
As long as I never run this command sudo update-initramfs -u -- it seems I am still able to run ZFS, even though it is version 2.2.2 and this should be incompatible with Linux kernel 6.8 ... I'm really not sure how stable it is, but at least if I avoid this sudo update-initramfs -u , then ZFS does seem to work...

[rincebrain]

See here for how Ubuntu broke that a long time ago.

[kingpalethe]

Thanks, are you sure that is the right link? That seems to be the main OpenZFS directions, which I found were outdated. Do you have any recommended strategy to install ZFS on Ubuntu?

[rincebrain]

On Ubuntu, for example, the modules from this repository install in the extra kernel module path, which is not in the standard depmod search path. Therefore, for the duration of your testing, edit /etc/depmod.d/ubuntu.conf and add extra to the beginning of the search path.

The instructions aren't outdated, you just skimmed them.

[kingpalethe]

Here is some relevant discussion. https://bugs.launchpad.net/ubuntu/+source/zfs-linux/+bug/2044657

From what I can understand, Canonical considers that 2.2.2 should still work with modern Ubuntu.

[rincebrain]

The Ubuntu instructions worked for me when I tried them just now in a 24.04 VM.

I would suggest you look at your installed packages, something like dpkg -l | grep -E '(zfs|zpool|nvpair)'. I would guess you have either a mix of packages, or stuff in /usr/local/ and packages, breaking it, offhand.

[kingpalethe]

Thanks.

I don't really have a reproducible test case unfortunately. But maybe this discussion will be found by other people who have this problem and they'll chime in.

My current understanding of the issue is......

1. I added this line options zfs zfs_arc_max=options zfs zfs_arc_max=8589934592 to /etc/modprobe.d/zfs.conf
2. I ran sudo update-initramfs -u
   This worked well for a while (a few days) until I blindly accepted this update from Canonical..... note that Canonical is clearly fiddling with initramfs here.

Once I accepted this update and rebooted, that killed ZFS and I got the Failed to initialize the libzfs library library when running sudo zpool status.

Then: I was able to solve the issue by wiping the system, starting from scratch, and NOT accepting this update from Canonical.

So I'm going to learn a lesson here: "If you use ZFS on Ubuntu, if you think you have it stable, never update your system."

This may or may not be correct, but at least I can leave it here and see if anyone else stumbles over this and finds this thread.

I would try to put this on Ubuntu's support forum ( https://ubuntuforums.org/ ) - but as far as I can tell, the search functionality of that forum is broken, it's very slow to load, and most of the commentary is very.... um... ANGRY.....

Thanks.

[rincebrain]

That line is not valid to put in any modprobe config file, so I suspect there's a typo there, or that's your problem.
Lines in there look like
options zfs foo=bar
or sometimes
blacklist foo

[rincebrain]

Also, those lines are basically just telling you "initramfs-tools" and "initramfs-tools-core" got updated, which is not that interesting a result.

You should probably try loading the module, manually, after rebooting and it breaks, and seeing if it errors, because then that tells you that's a problem.

[kingpalethe]

Yikes, user error then likely. Closing discussion. thanks.