The issue appears to be that update-initramfs creates uncompressed images. I have the same error but have been dealing with a different issue of it failing to boot with a custom kernel by UUID which is why I haven't posted a bug report. However, since this issue appears to be related, upon further inspection I find that none of the initramfs images being created are actually compressed at all.
file /boot/initrd.img* /boot/initrd.img: symbolic link to initrd.img-5.4.0-40-generic /boot/initrd.img-5.4.0-33-generic: ASCII cpio archive (SVR4 with no CRC) /boot/initrd.img-5.4.0-37-generic: ASCII cpio archive (SVR4 with no CRC) /boot/initrd.img-5.4.0-39-generic: ASCII cpio archive (SVR4 with no CRC) /boot/initrd.img-5.4.0-40-generic: ASCII cpio archive (SVR4 with no CRC) These should all be lz4 images. I tried changing the initramfs config to gzip but it still did not show a compressed file. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1835660 Title: initramfs unpacking failed Status in initramfs-tools package in Ubuntu: Invalid Status in linux package in Ubuntu: Confirmed Bug description: "initramfs unpacking failed: Decoding failed", message appears on boot up. If I "update-initramfs" using gzip instead of lz, then boot up passes without decoding failed message. --- However, we currently believe that the decoding error reported in dmesg is actually harmless and has no impact on usability on the system. Switching from lz4 to gzip compression, simply papers over the warning, without any benefits, and slows down boot. Kernel should be fixed to correctly parse lz4 compressed initrds, or at least lower the warning, to not be user visible as an error. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/initramfs-tools/+bug/1835660/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
