You have been subscribed to a public bug: mke2fs in all supported Ubuntu releases to date creates 'small' ext4 file systems with an inode size of 128. This is said to be insufficient to store time stamps referring to year 2038 and later (when the Unix epoch exceeds a signed 32-bit integer - https://en.wikipedia.org/wiki/Year_2038_problem). When such file systems are mounted by the kernel, such as a /boot file system created by the Ubuntu 20.04.0 Desktop installer (ubiquity 20.04.15), the kernel will warn about this fact:
kernel: ext4 filesystem being mounted at /boot supports timestamps until 2038 (0x7fffffff) Cf. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=953494 Admittedly, that's another 18 years, by when most systems installed now will be no longer in use, or will have been reinstalled. Also, on a /boot file system the 5.4.0-33-generic #37 Ubuntu (20.04) kernel warned about this, I was able to $ touch -t 203812312359 /tmp/test and got $ ls -l /tmp/test -rw-r--r-- 1 root root 0 Dez 31 2038 /tmp/test so this warning may not always apply, or patches may have been applied to handle this situation more gracefully already. Ubuntu 20.04 comes with e2fsprogs 1.45.5-2ubuntu1. Theodore Y. Ts'o has submitted patches for Debian's 1.45.6-1 - but (strictly speaking based on the changelog) these seem to be limited to documentation changes. Still, creating such file systems may seem undesirable in terms of forward compatibility. I therefore suggest to change the minimum inode size for mke2fs, as defined in /etc/mke2fs.conf, to 256 for all file systems which do not already use this value (maybe with the exception of floppies). That is, I suggest the following change to Ubuntu 20.04's /etc/mke2fs.conf: Before change: small = { inode_size = 128 inode_ratio = 4096 } After change: small = { inode_ratio = 4096 } This assumes that the default inode size is already set to 256 further above. As a WORKAROUND, after backing up the file system (this command is not well tested, according to the lead ext4 file system developer), users can unmount the affected file system and run tune2fs -I 256 /path/to/block_device where /path/to/block_device should be replaced by the path to the block device which contains the file system the kernel reports the warning for. For example, for the file system mounted at /boot, the findmnt /boot command would return the block device path in the SOURCE column. Please note I prefer not to use apport for this bug report, I believe it is already sufficiently complete. ** Affects: e2fsprogs (Ubuntu) Importance: Undecided Status: New ** Tags: focal -- Minimum inode size should be raised to 256 for forward compatibility (Y2038) https://bugs.launchpad.net/bugs/1881935 You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to e2fsprogs in Ubuntu. -- 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
