I tried this out, and it does indeed fix the problem I was seeing. Thanks! Nate -----Original Message----- From: Neil Brown [mailto:neilb@xxxxxxx] Sent: Wednesday, December 08, 2010 10:16 PM To: Dailey, Nate Cc: linux-raid@xxxxxxxxxxxxxxx Subject: Re: interrupted resync not restarted properly? On Tue, 7 Dec 2010 15:37:00 -0500 "Dailey, Nate" <Nate.Dailey@xxxxxxxxxxx> wrote: > It seems to me that resuming an interrupted resync doesn't always work > right... here's what I'm doing (kernel 2.6.36): > > - start with a 2 disk raid1 with internal bitmap > - fail/remove one disk and zero the superblock > - add the disk to the raid1 > - before resync completes, fail/remove the disk again > - re-add the disk again > > For version 0 superblocks, this works the way I'd expect: on adding the > disk the second time, the resync continues (or restarts from the > beginning, not sure). > > But for version 1 superblocks, on adding the disk the second time, the > resync completes immediately, leaving some part of the array > out-of-sync. > > Should there be something in the v1 superblock to prevent this? > > If the raid1 is stopped in the middle of the resync (instead of removing > the target disk) the resync is resumed correctly on re-assembly with > both devices. > > Nate > > -- > 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 Thanks for the report. That is pretty bad behaviour. The following is a patch that I plan to submit to -linus and -stable. It doesn't make it work quite as I would like (that would be a lot more code) but it makes it a lot safer. Thanks, NeilBrown --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -5170,7 +5174,10 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info) } else super_types[mddev->major_version]. validate_super(mddev, rdev); - rdev->saved_raid_disk = rdev->raid_disk; + if (test_bit(In_sync, &rdev->flags)) + rdev->saved_raid_disk = rdev->raid_disk; + else + rdev->saved_raid_disk = -1; clear_bit(In_sync, &rdev->flags); /* just to be sure */ if (info->state & (1<<MD_DISK_WRITEMOSTLY)) -- 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
