Re: Kernel 2.6.17 and RAID5 Grow Problem (critical section backup)

On Friday July 7, jpiszcz@lucidpixels.com wrote:

quoted

quoted

Jul  7 08:44:59 p34 kernel: [4295845.933000] raid5: reshape: not enough 
stripes.  Needed 512
Jul  7 08:44:59 p34 kernel: [4295845.962000] md: couldn't update array 
info. -28

So the RAID5 reshape only works if you use a 128kb or smaller chunk size?

Neil,

Any comments?

Yes.   This is something I need to fix in the next mdadm.
You need to tell md/raid5 to increase the size of the stripe cache
before the grow can proceed.  You can do this with

  echo 600 > /sys/block/md3/md/stripe_cache_size

Then the --grow should work.  The next mdadm will do this for you.

NeilBrown