On 10/18/07, Neil Brown <neilb@xxxxxxx> wrote:
>
> Sorry, I wasn't paying close enough attention and missed the obvious.
> .....
>
> On Thursday October 18, snitzer@xxxxxxxxx wrote:
> > On 10/18/07, Neil Brown <neilb@xxxxxxx> wrote:
> > > On Wednesday October 17, snitzer@xxxxxxxxx wrote:
> > > > mdadm 2.4.1 through 2.5.6 works. mdadm-2.6's "Improve allocation and
> > > > use of space for bitmaps in version1 metadata"
> > > > (199171a297a87d7696b6b8c07ee520363f4603c1) would seem like the
> > > > offending change. Using 1.2 metdata works.
> > > >
> > > > I get the following using the tip of the mdadm git repo or any other
> > > > version of mdadm 2.6.x:
> > > >
> > > > # mdadm --create /dev/md2 --run -l 1 --metadata=1.0 --bitmap=internal
> > > > -n 2 /dev/sdf --write-mostly /dev/nbd2
> > > > mdadm: /dev/sdf appears to be part of a raid array:
> > > > level=raid1 devices=2 ctime=Wed Oct 17 10:17:31 2007
> > > > mdadm: /dev/nbd2 appears to be part of a raid array:
> > > > level=raid1 devices=2 ctime=Wed Oct 17 10:17:31 2007
> > > > mdadm: RUN_ARRAY failed: Input/output error
> ^^^^^^^^^^^^^^^^^^
>
> This means there was an IO error. i.e. there is a block on the device
> that cannot be read from.
> It worked with earlier version of mdadm because they used a much
> smaller bitmap. With the patch you mention in place, mdadm tries
> harder to find a good location and good size for a bitmap and to
> make sure that space is available.
> The important fact is that the bitmap ends up at a different
> location.
>
> You have a bad block at that location, it would seem.
I'm a bit skeptical of that being the case considering I get this
error on _any_ pair of disks I try in an environment where I'm
mirroring across servers that each have access to 8 of these disks.
Each of the 8 mirrors consists of a local member and a remote (nbd)
member. I can't see all 16 disks having the very same bad block(s) at
the end of the disk ;)
I feels to me like the calculation that you're making isn't leaving
adequate room for the 128K bitmap without hitting the superblock...
but I don't have hard proof yet ;)
> I would have expected an error in the kernel logs about the read error
> though - that is strange.
What about the "md2: failed to create bitmap (-5)"?
> What do
> mdadm -E
> and
> mdadm -X
>
> on each device say?
# mdadm -E /dev/sdf
/dev/sdf:
Magic : a92b4efc
Version : 1.0
Feature Map : 0x1
Array UUID : caabb900:616bfc5a:03763b95:83ea99a7
Name : 2
Creation Time : Fri Oct 19 00:38:45 2007
Raid Level : raid1
Raid Devices : 2
Used Dev Size : 1464913648 (698.53 GiB 750.04 GB)
Array Size : 1464913648 (698.53 GiB 750.04 GB)
Super Offset : 1464913904 sectors
State : clean
Device UUID : 978cdd42:abaa82a1:4ad79285:1b56ed86
Internal Bitmap : -176 sectors from superblock
Update Time : Fri Oct 19 00:38:45 2007
Checksum : c6bb03db - correct
Events : 0
Array Slot : 0 (0, 1)
Array State : Uu
# mdadm -E /dev/nbd2
/dev/nbd2:
Magic : a92b4efc
Version : 1.0
Feature Map : 0x1
Array UUID : caabb900:616bfc5a:03763b95:83ea99a7
Name : 2
Creation Time : Fri Oct 19 00:38:45 2007
Raid Level : raid1
Raid Devices : 2
Used Dev Size : 1464913648 (698.53 GiB 750.04 GB)
Array Size : 1464913648 (698.53 GiB 750.04 GB)
Super Offset : 1464913904 sectors
State : clean
Device UUID : 180209d2:cff9b5d0:05054d19:2e4930f2
Internal Bitmap : -176 sectors from superblock
Flags : write-mostly
Update Time : Fri Oct 19 00:38:45 2007
Checksum : 8416e951 - correct
Events : 0
Array Slot : 1 (0, 1)
Array State : uU
# mdadm -X /dev/sdf
Filename : /dev/sdf
Magic : 6d746962
Version : 4
UUID : caabb900:616bfc5a:03763b95:83ea99a7
Events : 0
Events Cleared : 0
State : OK
Chunksize : 1 MB
Daemon : 5s flush period
Write Mode : Normal
Sync Size : 732456824 (698.53 GiB 750.04 GB)
Bitmap : 715290 bits (chunks), 715290 dirty (100.0%)
# mdadm -X /dev/nbd2
Filename : /dev/nbd2
Magic : 6d746962
Version : 4
UUID : caabb900:616bfc5a:03763b95:83ea99a7
Events : 0
Events Cleared : 0
State : OK
Chunksize : 1 MB
Daemon : 5s flush period
Write Mode : Normal
Sync Size : 732456824 (698.53 GiB 750.04 GB)
Bitmap : 715290 bits (chunks), 715290 dirty (100.0%)
> > > > mdadm: stopped /dev/md2
> > > >
> > > > kernel log shows:
> > > > md2: bitmap initialized from disk: read 22/22 pages, set 715290 bits, status: 0
> > > > created bitmap (350 pages) for device md2
> > > > md2: failed to create bitmap (-5)
I assumed that the RUN_ARRAY failed (via IO error) was a side-effect
of MD's inability to create the bitmap (-5):
md2: bitmap initialized from disk: read 22/22 pages, set 715290 bits, status: 0
created bitmap (350 pages) for device md2
md2: failed to create bitmap (-5)
md: pers->run() failed ...
md: md2 stopped.
So you're saying one has nothing to do with the other?
regards,
Mike
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