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

From: Justin Piszcz
Date: Mon Jul 10 2006 - 17:45:41 EST




On Sat, 8 Jul 2006, Neil Brown wrote:

On Friday July 7, jpiszcz@xxxxxxxxxxxxxxx wrote:

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

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

md3 : active raid5 sdc1[7] sde1[6] sdd1[5] hdk1[2] hdi1[4] hde1[3] hdc1[1] hda1[0]
2344252416 blocks super 0.91 level 5, 512k chunk, algorithm 2 [8/8] [UUUUUUUU]
[>....................] reshape = 0.2% (1099280/390708736) finish=1031.7min speed=6293K/sec

It is working, thanks!

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/