Identified that the command : update-initramfs: Generating /boot/initrd.img-5.11.0-38-generic
required approx 88M of disk space on /boot, but I only had 73M: df -h /boot bpool/BOOT/ubuntu_l3g9y7 286M 213M 73M 75% /boot Problem resolved by manually running zsys garbage collection (laptop, so scheduled jobs are unable to run when the laptop is off/hybernating. To demonstrate, use "zsysctl machine show to list the ZFS snapshots that are part of zsys. Use with wc to show the number of snapshots before garbage collection and after, hopefully with a reduction: zsysctl machine show|wc 127 468 7959 zsysctl service gc zsysctl machine show|wc 105 381 6350 Free space after this has run: df -lh /boot Filesystem Size Used Avail Use% Mounted on bpool/BOOT/ubuntu_l3g9y7 375M 202M 174M 54% /boot Monitoring the Avail space for boot while re-running apt upgrade : df -h /boot Filesystem Size Used Avail Use% Mounted on bpool/BOOT/ubuntu_l3g9y7 375M 289M 86M 78% /boot before returning to 174M available. zfs list -r bpool NAME USED AVAIL REFER MOUNTPOINT bpool 1.58G 174M 96K /boot bpool/BOOT 1.58G 174M 96K none bpool/BOOT/ubuntu_l3g9y7 1.58G 174M 201M /boot The used space in this case is in zfs snapshots, hence zsys garbage collection resolved this. Where zfs and zsys are installed, checking free space and "bloat" required space, with the option/suggestion to run "zsysctl service gc". -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1947871 Title: package linux-image-5.11.0-38-generic 5.11.0-38.42~20.04.1 failed to install/upgrade: run-parts: /etc/kernel/postinst.d/initramfs-tools exited with return code 1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/initramfs-tools/+bug/1947871/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs