On Wed, 11 Aug 2010 11:46:22 +0200
Tobias Gunkel [off-list ref] wrote:

Am 11.08.2010 09:57, schrieb Neil Brown:

quoted

This means that /etc/mdadm/mdadm.conf says /dev/md2 has more spare devices
than it currently has.  What is in /etc/mdadm/mdadm.conf

root@MCI03:~# egrep -v '^#|^$' /etc/mdadm/mdadm.conf
DEVICE partitions
CREATE owner=root group=disk mode=0660 auto=yes
HOMEHOST <system>
ARRAY /dev/md0 UUID=304f5f2a:fbc8082b:54307b3d:1949437b
   spares=1
ARRAY /dev/md1 UUID=b263f9c1:5c680152:54307b3d:1949437b
   spares=1
ARRAY /dev/md2 UUID=7aa24776:9d6e8d24:54307b3d:1949437b
   spares=2
MAILADDR foo@bar.com

As I thought, mdadm.conf says to expect 2 spares, but there is really only
one.  Just edit the file and the message will stop.

quoted

What do you get if you run

 mdadm --examine --scan --verbose

root@MCI03:~# mdadm --examine --scan --verbose
ARRAY /dev/md0 level=raid1 num-devices=2
UUID=304f5f2a:fbc8082b:54307b3d:1949437b
   spares=1   devices=/dev/sdc1,/dev/sdb1,/dev/sda1
ARRAY /dev/md1 level=raid1 num-devices=2
UUID=b263f9c1:5c680152:54307b3d:1949437b
   spares=1   devices=/dev/sdc2,/dev/sdb2,/dev/sda2
ARRAY /dev/md2 level=raid1 num-devices=2
UUID=7aa24776:9d6e8d24:54307b3d:1949437b
   spares=2
devices=/dev/sdc3,/dev/sdc,/dev/sdb3,/dev/sdb,/dev/sda3,/dev/sda


Hm, md2 contains devices. How is that?

Partition3 on each device must start at a multiple of 64K and extend to then
end of the device.  In this case both the partition and the whole device
appear to have the same metadata, and mdadm cannot tell which is correct.
This is a short-coming of v0.90 metadata and is fixed in v1.x.
You can avoid this by changing the 'device' line in mdadm.conf to

   DEVICE /dev/sd*[0-9]

which essentially means "only partitions of sd devices should be considered
for membership in md arrays".

NeilBrown

Tobi
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