Neil Brown wrote:

On Tuesday June 12, T_Wolf@gmx.net wrote:
  

quoted

Hello everyone.

I've got a SLES9 SP3 running and I've been quite happy with it so far.

Recently, I've created a 4 disk spanning RAID-5 on our company
server. Runs quite nice and we're happy with that too. I created
that RAID using the SLES mdadm (1.4 I believe) package. 

After discovering that there is a much newer mdadm out here (2.6.1),
I decided to upgrade. It went just fine. Raid still running at 120
MB/sec. 

After adding a disk to the raid, which went fine as well...... BUT:

The added disk /dev/sda1 shows up in /proc/mdstat, but does not have
the "spare (s)" flag. 

Plus... the --grow doesn't work...

I get the: mdadm: /dev/md0: Cannot get array details from sysfs
error which has been discussed before. Can it be that this is caused
by the 2.6.5-7.2xx Kernel? Any ideas? 
    

Yes.  All of your issues are caused by using a 2.6.5 based kernel.
However even upgrading to SLES10 would not get you raid5-grow.  That
came a little later.  You would need to compile a mainline kernel or
wait for SLES11.

I have to think that if features require a later kernel version that a 
warning message would be appropriate. I'm always leary about trying a 
new mdadm version with a vendor kernel unless it's a minor bugfix problem.

-- 
bill davidsen [off-list ref]
  CTO TMR Associates, Inc
  Doing interesting things with small computers since 1979