On Mon, Dec 15, 2008 at 2:09 PM, Neil Brown <neilb@xxxxxxx> wrote: > On Monday December 15, jnelson-linux-raid@xxxxxxxxxxx wrote: >> I have a software raid1 which underwent a recovery recently. >> While it was recovering, I could not understand why I was seeing an >> equal amount of *read* I/O as write I/O to the device the raid1 was >> recovering to. That's to say, the raid1 was rebuilding on to a spare >> but instead of just writing I was seeing (nearly exactly) the same >> amount of read I/O as write I/O. The non-spare device was getting >> almost exclusively read I/O as expected. Why was the spare getting any >> read I/O at all? > > It sounds like it is doing a 'repair' rather than a 'recover'. > 'repair' happens when you write the word 'repair' to > /sys/block/mdX/md/sync_action. > > In situations like this it is always best to provide lots of detail. > e.g. kernel logs of the time when things were happening, "mdadm -E" or > all devices. The exact data you looked at to make you think there was > something going wrong (in this case, whatever statistics you found > that suggested lots of read requests). > > Without those specifics it is hard to try to reproduce, and hard to > guess what was actually happening. > Yes it is hard to guess what is happening here; however, should not the following commit go to -stable? http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=56ac36d722d0d27c03599d1245ac0ab59e474e5c Regards, 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
