I have recently upgraded one of my debian servers from version 10 to 11.
My surprise when I wanted to mount my zfs pools after upgrade: zfs packages (zpool, zfs, etc) were missing.
I have upgraded debian in the past and usually this problem was solved with:
dpkg-reconfigure zfs-dkms.
Not this time...
Digging more I found out some packages were missing so I had to install zfsutils-linux package:
I am not sure why it has been uninstalled, probably during the upgrade process but no worries, the installation was successful and zfs commands were available again :)
root@candy:~# apt install zfs-dkms zfsutils-linux Reading package lists... Done Building dependency tree... Done Reading state information... Done zfs-dkms is already the newest version (2.0.3-9). The following additional packages will be installed: libnvpair3linux libuutil3linux libzfs4linux libzpool4linux zfs-zed Suggested packages: samba-common-bin zfs-initramfs | zfs-dracut The following NEW packages will be installed: libnvpair3linux libuutil3linux libzfs4linux libzpool4linux zfs-zed zfsutils-linux 0 upgraded, 6 newly installed, 0 to remove and 0 not upgraded. Need to get 2,150 kB of archives. After this operation, 6,954 kB of additional disk space will be used. Do you want to continue? [Y/n] Get:1 http://deb.debian.org/debian bullseye/contrib amd64 libnvpair3linux amd64 2.0.3-9 [61.2 kB] Get:2 http://deb.debian.org/debian bullseye/contrib amd64 libuutil3linux amd64 2.0.3-9 [54.0 kB] Get:3 http://deb.debian.org/debian bullseye/contrib amd64 libzfs4linux amd64 2.0.3-9 [231 kB] Get:4 http://deb.debian.org/debian bullseye/contrib amd64 libzpool4linux amd64 2.0.3-9 [1,247 kB] Get:5 http://deb.debian.org/debian bullseye/contrib amd64 zfsutils-linux amd64 2.0.3-9 [481 kB] Get:6 http://deb.debian.org/debian bullseye/contrib amd64 zfs-zed amd64 2.0.3-9 [75.4 kB] Fetched 2,150 kB in 1s (1,626 kB/s) Selecting previously unselected package libnvpair3linux. (Reading database ... 76616 files and directories currently installed.) Preparing to unpack .../0-libnvpair3linux_2.0.3-9_amd64.deb ... Unpacking libnvpair3linux (2.0.3-9) ... Selecting previously unselected package libuutil3linux. Preparing to unpack .../1-libuutil3linux_2.0.3-9_amd64.deb ... Unpacking libuutil3linux (2.0.3-9) ... Selecting previously unselected package libzfs4linux. Preparing to unpack .../2-libzfs4linux_2.0.3-9_amd64.deb ... Unpacking libzfs4linux (2.0.3-9) ... Selecting previously unselected package libzpool4linux. Preparing to unpack .../3-libzpool4linux_2.0.3-9_amd64.deb ... Unpacking libzpool4linux (2.0.3-9) ... Selecting previously unselected package zfsutils-linux. Preparing to unpack .../4-zfsutils-linux_2.0.3-9_amd64.deb ... Unpacking zfsutils-linux (2.0.3-9) ... Selecting previously unselected package zfs-zed. Preparing to unpack .../5-zfs-zed_2.0.3-9_amd64.deb ... Unpacking zfs-zed (2.0.3-9) ... Setting up libnvpair3linux (2.0.3-9) ... Setting up libuutil3linux (2.0.3-9) ... Setting up libzfs4linux (2.0.3-9) ... Setting up libzpool4linux (2.0.3-9) ... Setting up zfsutils-linux (2.0.3-9) ... insmod /lib/modules/5.10.0-9-amd64/updates/dkms/spl.ko insmod /lib/modules/5.10.0-9-amd64/updates/dkms/znvpair.ko insmod /lib/modules/5.10.0-9-amd64/updates/dkms/zcommon.ko insmod /lib/modules/5.10.0-9-amd64/updates/dkms/icp.ko insmod /lib/modules/5.10.0-9-amd64/updates/dkms/zavl.ko insmod /lib/modules/5.10.0-9-amd64/updates/dkms/zlua.ko insmod /lib/modules/5.10.0-9-amd64/updates/dkms/zzstd.ko insmod /lib/modules/5.10.0-9-amd64/updates/dkms/zunicode.ko insmod /lib/modules/5.10.0-9-amd64/updates/dkms/zfs.ko zfs-import-scan.service is a disabled or a static unit, not starting it. Setting up zfs-zed (2.0.3-9) ... Processing triggers for man-db (2.9.4-2) ... Processing triggers for libc-bin (2.31-13+deb11u2) ...
Enjoy!
