On Tue, Dec 10, 2024 at 06:28:28PM -0500, Demi Marie Obenour wrote: > >> Was https://github.com/util-linux/util-linux/issues/1305 a > >> collision between ZFS and ext4? > > > > Yes, but in this case, ZFS was incorrectly detected. As you can see > > from the bug report, blkid ended with an "ambiguous result" error. mke2fs (mkfs.ext4) does attempt to zero the typical locations where conflicting superblocks might be found. The ext4 metadata is located at the beginning of the file system, except for the first 1k, which we leave zero out on all platforms except for Sparc (the exact reason is lost in the midsts of time, since it pre-exists git, but as I recall Sparc had something critical that would cause its BIOS to lose its marbles if we zeroed it out), and we also zero out the very end of the disk where the MD superblock is located. It sounds like ZFS is putting its superblock someplace random that mke2fs ext4 doesn't know about. If someone wants to do the research to let me know what needs to be zeroed out to zap the ZFS superblock, please feel to file a bug against e2fsck (or better yet, send me a patch :-P ) and I'll be happy to add support for it. > >> /etc/fstab provides an explicit filesystem type. The Discoverable > >> Partition Specification doesn't.
