Red Hat Bugzilla – Bug 28768
Parallel fsck fails to parallelize properly.
Last modified: 2007-04-18 12:31:38 EDT
fsck checks my /boot and /home partitions simultaneously, causing lots of disk thrashing and taking longer than it would otherwise. Both have fsck priority 2 in fstab, which is what anaconda assigned at install time.
Parallel checks should only be done on different disks, but never on partitions of the same disk. I think that this should be assigned to the anaconda maintainers.
Fresh install of Wolverine does the same thing. /, /boot, and /home are all on /dev/hde, and while / has priority 1, /boot and /home have priority 2 in fstab. After an unclean shutdown, e2fsck thrashes the disk checking /boot and /home at the same time. Not a _big_ problem for me (boot is small), but when I had things partitioned as /usr and /home, this was a major issue. :-/
After RTFM, it seems that anaconda is indeed correct in assigning passno=2 to all non-root filesystems, and e2fsck is responsible for parallelizing properly. IIRC parallelized fsck worked properly in RH6.2, and my uninformed guess would be that mount-by-label might be the causative factor. Testing this hypothesis now ... meanwhile, reassigning to e2fsprogs.
fsck does parallelize properly with explicit device names in fstab. Using LABEL= notation in fstab seems to break fsck's drive ordering.
This should be fixed with e2fsprogs-1.19-2. Thanks for the bug-report.
This is still broken in 1.19-3. I'm investigating.
I somehow suspect that this has the same root cause as getting a "Couldn't find filesystem: LABEL=/somelabel" error on fsck at startup. Although that is *really* weird because it ONLY happens when fsck is run by initlog. It does NOT happen when fsck is run directly from rc.sysinit. Jeeeezuz. WTF could be happening there? And it ONLY happens on system startup. Great. ONLY on system startup, from rc.sysinit, ONLY when initlog is the parent of fsck. Aaaauuuugggghhhhh! Debug that, Batman!
Oh... I'm running Wolverine with Rawhides e2fsprogs (1.19-3). So I've got the latest and greatest here. Bleah.
See bug 35980 for a major fix to problems with LABEL/UUID.
This does appear to be working in 7.1-release. I'll do some further checking to make sure this is the case.
Ok, closing bug. e2fsprogs-1.20 will have even better code to detect partitions on the same disk. Thanks for the bug-report, Florian La Roche