On Sun, Jul 15, 2012 at 10:32:01PM -0600, Andreas Dilger wrote: > On 2012-07-15, at 20:56, Kevin Shanahan <kmshanah@xxxxxxxxxxxxxx> wrote: > > > On Mon, Jul 16, 2012 at 09:10:58AM +0930, Kevin Shanahan wrote: > >> I have created some filesystems with external journals, and after > >> reboot (clean shutdown) these will not mount anymore. I see in dmesg: > >> > >> [42214.365496] EXT4-fs (dm-10): journal UUID does not match > >> > >> However, the UUIDs look fine when viewed with dumpe2fs: > >> > > Here is what e2fsck said about it. > > > > # e2fsck -p -j /dev/ssdvg/jnl-kvmhost0 /dev/it8/nfs-kvmhost0 > > /dev/it8/nfs-kvmhost0: Superblock hint for external superblock should be 0xfd0d. FIXED. > > /dev/it8/nfs-kvmhost0: clean, 43229/983040 files, 303609/3932160 blocks > > > > I guess that is the "Journal Device" field? Mount worked fine after > > that and the data looks okay. > > > > Any idea how this might have happened across all three fs with > > external journals? > > Because LVM changed the block device numbers after the reboot, and > the device number used previously for the external journal was > different. > > The lookup of the journal by UUID (instead of relying on the "device > hint" in the superblock) _should_ be handled by mount, but I don't > recall if we ever got a mount.ext4 to handle this or not. It would > also be possible for the "fast e2fsck" check to verify the journal > UUID before mounting the filesystem, but again I'm not sure if this > is done yet, and I can't check right now. Ok, thanks. For now I can ask LVM to make the major/minor number persistent. Assuming it's not already done, do you think adding the UUID lookup would be a reasonable project for a newbie or is it likely to be a bit complicated? I'm assuming support is not there, at least for the versions in Arch: $ pacman -Q e2fsprogs util-linux e2fsprogs 1.42.4-1 util-linux 2.21.2-5 Cheers, Kevin. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
