An issue for 18.04 too, reported in IRC. There is a related bug "Ubuntu 12.04 LTS, 14.04 LTS, 16.04 LTS do not support ext4 metadata checksumming"
https://bugs.launchpad.net/ubuntu/+source/e2fsprogs/+bug/1365874 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1601997 Title: Ubuntu 16.10 installer sets metadata_csum option on ext4 partition which is incompatible with other LTS Ubuntu versions To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/e2fsprogs/+bug/1601997/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
