Comment 3 for bug 1914287

I've just realised (newbie here :-)) that /var/log/apt/history.* has information on package versions which may be useful.

Linux version before/after problem:

Start-Date: 2021-01-28 15:42:31
Commandline: apt-get dist-upgrade
Requested-By: ubuntu (1000)
Install: linux-image-5.4.0-1028-raspi:arm64 (5.4.0-1028.31, automatic), linux-headers-5.4.0-1028-raspi:arm64 (5.4.0-1028.31, automatic), linux-modules-5.4.0-1028-raspi:arm64 (5.4.0-1028.31, automatic), linux-raspi-headers-5.4.0-1028:arm64 (5.4.0-1028.31, automatic)
Upgrade: lshw:arm64 (02.18.85-0.3ubuntu2, 02.18.85-0.3ubuntu2.20.04.1), libc6:arm64 (2.31-0ubuntu9.1, 2.31-0ubuntu9.2), locales:arm64 (2.31-0ubuntu9.1, 2.31-0ubuntu9.2), libc-bin:arm64 (2.31-0ubuntu9.1, 2.31-0ubuntu9.2), linux-raspi:arm64 (5.4.0.1026.61, 5.4.0.1028.63), linux-image-raspi:arm64 (5.4.0.1026.61, 5.4.0.1028.63), linux-headers-raspi:arm64 (5.4.0.1026.61, 5.4.0.1028.63)
End-Date: 2021-01-28 15:52:33

zfs versions (earlier version was running before and after problem started):

Start-Date: 2021-02-01 14:07:23
Commandline: apt-get dist-upgrade
Requested-By: ubuntu (1000)
Upgrade: zfs-zed:arm64 (0.8.3-1ubuntu12.5, 0.8.3-1ubuntu12.6), zfsutils-linux:arm64 (0.8.3-1ubuntu12.5, 0.8.3-1ubuntu12.6), libzfs2linux:arm64 (0.8.3-1ubuntu12.5, 0.8.3-1ubuntu12.6), libzpool2linux:arm64 (0.8.3-1
ubuntu12.5, 0.8.3-1ubuntu12.6), libnvpair1linux:arm64 (0.8.3-1ubuntu12.5, 0.8.3-1ubuntu12.6), libuutil1linux:arm64 (0.8.3-1ubuntu12.5, 0.8.3-1ubuntu12.6)
End-Date: 2021-02-01 14:08:43