On Tue, 09 Aug 2011 18:07:56 -0700 Daniel Frey <djqfrey@xxxxxxxxx> wrote: > On 08/08/11 16:34, NeilBrown wrote: > > > > When there have been no writes for a little while, mdmon will notice and mark > > the array as 'clean'. It will then mark it 'dirty' before the first write is > > allowed to proceed. > > On a clean shutdown of the array it will mark that array as 'clean'. > > > > But for you, the system shuts down with the array marked 'dirty'. This > > suggests that on your machine 'mdmon' is being killed while the array is > > still active. > > > > Presumably your root is on the IMSM RAID10 array? When the root filesystem > > is marked 'read only' it will probably write to the filesystem to record that > > a fsck is not needed. So the array will be 'dirty'. If you then halt before > > mdmon has a chance to mark the array 'clean' you will get exactly the result > > you see. > > > > If you arrange that the shutdown script runs > > mdadm --wait-clean --scan > > > > after marking the root filesystem readonly, it will wait until all arrays are > > recorded as 'clean'. > > > > Neil, > > I see by the switches it is watching /proc/mdstat for updates, but /proc > was likely unmounted earlier in the shutdown process, and root is now > read-only. It need /proc, /sys, and /dev (assuming udev). There is really no point in unmounting any of these as they are virtual. Unmount everything else, remount root readonly, then "mdadm --wait-clean". However I would expect missing filesystems to cause an early failure rather than a hang. If mdmon had been killed already that might cause a bit of a hang, but it should be limited to 5 seconds. Maybe run 'mdadm --wait-clean --scan' under 'strace' and see what it is doing?? NeilBrown > > I've put it in the shutdown scripts and the system hangs on shutdown - > I've traced the hang to the command I put in above `mdadm --wait-clean > --scan`. > > Is it possible it's waiting for a write somewhere? I'm so close to > having it working now... > > Dan -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
