Given that files disappear that we just unpacked this makes me believe your file system is broken. I can see hanging kernel tasks in your journal at the top, but it's too truncated. journald also is corrupted:
Apr 27 21:05:17 username systemd-journald[64573]: File /run/log/journal/8bc63ca0b06d4ff59de1eb269b4ccb7a/system.journal corrupted or uncleanly shut down, renaming and replacing. I'd suggest running fsck. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2063981 Title: Noble Numbat distribution upgrade failure too many errors To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/2063981/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
