On 08/06/11 03:18, Erwan Leroux wrote:

Can you post the content of /etc/mdadm/mdadm.conf ?

Yep. This is my /etc/mdadm.conf:

ARRAY /dev/md/imsm0 metadata=imsm UUID=ec239ccc:22b7330b:0c4808ff:82dd176b
ARRAY /dev/md/HDD_0 container=/dev/md/imsm0 member=0
UUID=f61f87fc:1e85f04b:59e873c5:0afdb987

I noticed that if the ARRAY line contains the name parameter, the raid
is not started properly
ARRAY /dev/md/raid metadata=1.2
UUID=906ce226:19afa04f:12aab3c1:f91daa96 name=Serveur:raid

That doesn't seem to be the problem here.

you just have to remove the parameter and everything go back to normal.

Mayre be you're in this case, but you mentionned dual-boot, so perhaps
your problem is related to

I've done quite a bit more testing and it's definitely mdadm.

Starting from a clean array:
-Booting into Windows is fine, the array is not degraded
-Then rebooting into Windows, the array is fine not degraded
-Then rebooting into linux, the array is OK
-From there, rebooting into either Windows or linux the array is
degraded and the array starts to rebuild.

It's definitely mdadm causing the array to rebuild itself.

I've rolled a kernel with dmraid-1.0.0-rc16 and the problem is
completely gone.

I've got two kernels on this machine now and I can boot between the
mdadm and dmraid kernels, provided I remember to update the /etc/fstab
before I reboot. Even now, going into the mdadm kernel the rebuilding
issue still happens. I've not changed any of the rc scripts after
building the dmraid kernel, stuff just worked.

I'd much rather use mdadm, as dmraid was far harder to get to work for
some reason... well, it's mostly because I am not used to building my
own initramfs and was using one of gentoo's helpers (genkernel.) I
managed to get the tools to use the most recent mdadm and dmraid, after
much head-scratching.

Dan

Cordialy,

Erwan Leroux

2011/8/5 Daniel Frey [off-list ref]:

quoted

Hi all,

I've been fighting with my raid array (imsm - raid10) for several weeks
now. I've now replaced all four drives in my array as the constant
rebuilding caused a smart error to trip on the old drives; unfortunately
mdadm is still resyncing the array at every boot.

One thing I would like to clarify is does mdadm need to disassemble the
array before reboot. At this point, I can't tell if my system is
currently doing this. Googling around it seems some say that this step
is unnecessary.

I've managed to update initramfs to 3.2.1 and the local system to 3.2.1
but the problem still persists.

The last thing my system does is remount root ro, which it does
successfully. However, at the next start:

[   12.657829] md: md127 stopped.
[   12.660652] md: bind<sdc>
[   12.660939] md: bind<sdb>
[   12.661212] md: bind<sda>
[   12.661282] md: bind<sdd>
[   12.664972] md: md126 stopped.
[   12.665284] md: bind<sdd>
[   12.665383] md: bind<sdc>
[   12.665476] md: bind<sdb>
[   12.665568] md: bind<sda>
[   12.669218] md/raid10:md126: not clean -- starting background
reconstruction
[   12.669221] md/raid10:md126: active with 4 out of 4 devices
[   12.669241] md126: detected capacity change from 0 to 1000210432000
[   12.678356] md: md126 switched to read-write mode.
[   12.678390] md: resync of RAID array md126
[   12.678393] md: minimum _guaranteed_  speed: 1000 KB/sec/disk.
[   12.678395] md: using maximum available idle IO bandwidth (but not
more than 200000 KB/sec) for resync.
[   12.678399] md: using 128k window, over a total of 976768256 blocks.

and cat /proc/mdstat shows it resyncing:

# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10]
md126 : active raid10 sda[3] sdb[2] sdc[1] sdd[0]
     976768000 blocks super external:/md127/0 64K chunks 2 near-copies
[4/4] [UUUU]
     [==>..................]  resync = 12.2% (119256896/976768256)
finish=100.7min speed=141865K/sec

md127 : inactive sdd[3](S) sda[2](S) sdb[1](S) sdc[0](S)
     9028 blocks super external:imsm

unused devices: <none>

When it resyncs it is fine until the next power down.

Some other details:

# mdadm --detail-platform
      Platform : Intel(R) Matrix Storage Manager
       Version : 9.6.0.1014
   RAID Levels : raid0 raid1 raid10 raid5
   Chunk Sizes : 4k 8k 16k 32k 64k 128k
     Max Disks : 7
   Max Volumes : 2
 I/O Controller : /sys/devices/pci0000:00/0000:00:1f.2 (SATA)
         Port0 : /dev/sda (WD-WCAYUJ525606)
         Port1 : /dev/sdb (WD-WCAYUJ525636)
         Port2 : /dev/sdc (WD-WCAYUX093587)
         Port3 : /dev/sdd (WD-WCAYUX092774)
         Port4 : - non-disk device (TSSTcorp CDDVDW SH-S203B) -
         Port5 : - no device attached -

# mdadm --detail --scan
ARRAY /dev/md/imsm0 metadata=imsm UUID=ec239ccc:22b7330b:0c4808ff:82dd176b
ARRAY /dev/md/HDD_0 container=/dev/md/imsm0 member=0
UUID=f61f87fc:1e85f04b:59e873c5:0afdb987

# ls /dev/md
HDD_0  HDD_0p1  HDD_0p2  HDD_0p3  HDD_0p4  imsm0

Everything seems to be working. Also, I can't reproduce the results in
Windows Vista x64 (dual-boot.) When I go from linux -> Windows, Windows
detects the array as bad and reinitializes it as well, but if I reboot
into Windows the array survives without being marked bad.

Can anyone shed some light on this? I've been bashing my head on my desk
for too long and have run out of ideas.

Dan
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