This appears to be because of the limited remaining space in the /boot partition but the partition layout and sizes were automatically configured by the Ubuntu installer, which seems to be the culprit here.
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to initramfs-tools in Ubuntu. https://bugs.launchpad.net/bugs/1900748 Title: update-initramfs fails with an error 'Error 24 : Write error : cannot write compressed block' Status in initramfs-tools package in Ubuntu: New Bug description: On a VirtualBox 6.1.14 VM with 2 vCPUs and 8 GB RAM and a 10 GiB hard disk space, I installed Ubuntu 20.10 with ZFS enabled on a full disk installation using the latest installer ISO available on the Ubuntu releases site. After installation, I booted into the installed OS and tried to install all the package updates. It went mostly fine till when it tried to run the update-initramfs operation and failed. Below are the relevant messages printed to the console. <snip> Setting up initramfs-tools (0.137ubuntu12) ... update-initramfs: deferring update (trigger activated) Processing triggers for initramfs-tools (0.137ubuntu12) ... update-initramfs: Generating /boot/initrd.img-5.8.0-25-generic Error 24 : Write error : cannot write compressed block E: mkinitramfs failure cpio 141 lz4 -9 -l 24 update-initramfs: failed for /boot/initrd.img-5.8.0-25-generic with 1. dpkg: error processing package initramfs-tools (--configure): installed initramfs-tools package post-installation script subprocess returned error exit status 1 Errors were encountered while processing: initramfs-tools ZSys is adding automatic system snapshot to GRUB menu </snip> I checked the free disk space to ensure that there is enough available. <snip> guruprasad@groovy:~$ df -h Filesystem Size Used Avail Use% Mounted on tmpfs 796M 1.5M 795M 1% /run /dev/mapper/keystore-rpool 453M 748K 419M 1% /run/keystore/rpool rpool/ROOT/ubuntu_slz5nq 6.0G 3.9G 2.1G 66% / tmpfs 3.9G 33M 3.9G 1% /dev/shm tmpfs 5.0M 4.0K 5.0M 1% /run/lock tmpfs 4.0M 0 4.0M 0% /sys/fs/cgroup bpool/BOOT/ubuntu_slz5nq 268M 197M 71M 74% /boot rpool/USERDATA/guruprasad_bdqa1x 2.1G 32M 2.1G 2% /home/guruprasad /dev/sda2 512M 19M 494M 4% /boot/efi rpool/ROOT/ubuntu_slz5nq/var/snap 2.1G 384K 2.1G 1% /var/snap rpool/ROOT/ubuntu_slz5nq/usr/local 2.1G 512K 2.1G 1% /usr/local rpool/ROOT/ubuntu_slz5nq/srv 2.1G 256K 2.1G 1% /srv rpool/ROOT/ubuntu_slz5nq/var/lib 3.0G 933M 2.1G 31% /var/lib rpool/ROOT/ubuntu_slz5nq/var/www 2.1G 256K 2.1G 1% /var/www rpool/USERDATA/root_bdqa1x 2.1G 256K 2.1G 1% /root rpool/ROOT/ubuntu_slz5nq/var/log 2.1G 25M 2.1G 2% /var/log rpool/ROOT/ubuntu_slz5nq/var/spool 2.1G 384K 2.1G 1% /var/spool rpool/ROOT/ubuntu_slz5nq/var/games 2.1G 256K 2.1G 1% /var/games rpool/ROOT/ubuntu_slz5nq/var/mail 2.1G 256K 2.1G 1% /var/mail rpool/ROOT/ubuntu_slz5nq/var/lib/AccountsService 2.1G 384K 2.1G 1% /var/lib/AccountsService rpool/ROOT/ubuntu_slz5nq/var/lib/NetworkManager 2.1G 256K 2.1G 1% /var/lib/NetworkManager rpool/ROOT/ubuntu_slz5nq/var/lib/dpkg 2.2G 59M 2.1G 3% /var/lib/dpkg rpool/ROOT/ubuntu_slz5nq/var/lib/apt 2.2G 77M 2.1G 4% /var/lib/apt tmpfs 796M 188K 796M 1% /run/user/1000 </snip> ProblemType: Bug DistroRelease: Ubuntu 20.10 Package: initramfs-tools 0.137ubuntu12 ProcVersionSignature: Ubuntu 5.8.0-25.26-generic 5.8.14 Uname: Linux 5.8.0-25-generic x86_64 NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair ApportVersion: 2.20.11-0ubuntu50 Architecture: amd64 CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Tue Oct 20 23:05:25 2020 InstallationDate: Installed on 2020-10-20 (0 days ago) InstallationMedia: Ubuntu 20.10 "Groovy Gorilla" - Beta amd64 (20200930) PackageArchitecture: all RebootRequiredPkgs: evolution-data-server gnome-shell SourcePackage: initramfs-tools UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/initramfs-tools/+bug/1900748/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
