Lineal RAID wont work since i Update 7.7.0-1 (Sandworm)

A linear array has no redundancy, so I hope you have back ups.

The use of a "mdadm --create" on an existing array should always be a last resort and can easily cause data loss etc.

Luckily even though you ignored the "continue" warning the command failed.

The problem is with the backport kernel Linux 6.12.9+bpo-amd64 that was part of the update. If you check your logs you should see a error message like this:

kernel: md: personality for level -1 is not loaded!

The workaround is to revert to the previous stable kernel 6.1.0-31-amd64 that should still be on your system. If your system is attached to a screen and keyboard you can just re-boot the previous kernel via the grub menu.

But it is more convenient to first install the kernel plugin ( openmediavault-kernel 7.1.4 ) and then set the previous kernel as the default and reboot.

Your RAID array should then be recognised again

I've updated my OMV installation as well. I noticed a KVM package being held back. So I enabled backports in OMV extras as per instruction here to be able to finish the updates. Unfortunately, that caused my zfs file system to vanish. The server boots fine from the separate SSD, but everything from the zfs pool on the two data storage SSDs is inaccessible. The drives themselves are fine according to SMART.

I fear to make the wrong steps and kill something permanently if that's not already happened. Is my problem related to the abovementioned? Or shall I open a new thread?

Attempting to access the zfs pool yields:

Failed to execute command 'export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin; export LC_ALL=C.UTF-8; export LANGUAGE=; zfs list -p -H -t all -o name,type 2>&1' with exit code '1': The ZFS modules cannot be auto-loaded.
Try running 'modprobe zfs' as root to manually load them.

OMV\ExecException: Failed to execute command 'export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin; export LC_ALL=C.UTF-8; export LANGUAGE=; zfs list -p -H -t all -o name,type 2>&1' with exit code '1': The ZFS modules cannot be auto-loaded.
Try running 'modprobe zfs' as root to manually load them. in /usr/share/php/openmediavault/system/process.inc:247
Stack trace:
#0 /usr/share/omvzfs/Utils.php(450): OMV\System\Process->execute()
#1 /usr/share/omvzfs/Utils.php(262): OMVModuleZFSUtil::exec()
#2 /usr/share/openmediavault/engined/rpc/zfs.inc(297): OMVModuleZFSUtil::getZFSFlatArray()
#3 [internal function]: OMVRpcServiceZFS->listPools()
#4 /usr/share/php/openmediavault/rpc/serviceabstract.inc(124): call_user_func_array()
#5 /usr/share/php/openmediavault/rpc/serviceabstract.inc(155): OMV\Rpc\ServiceAbstract->callMethod()
#6 /usr/share/php/openmediavault/rpc/serviceabstract.inc(628): OMV\Rpc\ServiceAbstract->OMV\Rpc\{closure}()
#7 /usr/share/php/openmediavault/rpc/serviceabstract.inc(152): OMV\Rpc\ServiceAbstract->execBgProc()
#8 /usr/share/openmediavault/engined/rpc/zfs.inc(304): OMV\Rpc\ServiceAbstract->callMethodBg()
#9 [internal function]: OMVRpcServiceZFS->listPoolsBg()
#10 /usr/share/php/openmediavault/rpc/serviceabstract.inc(124): call_user_func_array()
#11 /usr/share/php/openmediavault/rpc/rpc.inc(86): OMV\Rpc\ServiceAbstract->callMethod()
#12 /usr/sbin/omv-engined(544): OMV\Rpc\Rpc::call()
#13 {main}

I'd be very grateful for assistance!

Here is additional information concerning the kernel versions.

I am confused about the latest kernel. I thought the pve version is the correct one. At least that's the one which was previously used in combination with proxmox.

FatherRandom Just select the PVE kernel and set that as the default to boot from and all should be OK.

That did the trick! Thank you very much. EVen though I have backups I was mightily scared!

Quote from FatherRandom

That did the trick! Thank you very much. EVen though I have backups I was mightily scared!

You could argue that once you switch from debian to pve kernels you should delete all debian kernels from OMV. The last OMV update included debian kernel 6.12.9 from backports which became the default boot kernel. Unfortunately you did not notice that the associated zfs modules did not build against this kernel which gave the appearance of losing your zfs pool. Of course, the whole point of using the PVE kernel is to avoid the use of the debian DKMS system which is only going to work if the version of zfs-dkms package ( and its dependencies) on your system is also from debian backports.

Personally, I advise OMV ZFS users to start by installing the kernel plugin before the zfs plugin. Install a pve kernel, re-boot and delete any debian kernel and then install the zfs-plugin.

Merci a vous pour le problème concernant les raid linéaire. La solution de rester sur l'ancien noyau grâce au plug-in fonctionne parfaitement

Quote from Krisbee

...

Personally, I advise OMV ZFS users to start by installing the kernel plugin before the zfs plugin. Install a pve kernel, re-boot and delete any debian kernel and then install the zfs-plugin.

I beg your pardon for answering months later! Thanks for your explanation concerning the pve kernel and zfs! Since I obviously followed a different order during installation I wonder whether I can still "heal" this. Would it suffice just to uninstall all non-pve kernels?