On 06/27/2011 05:21 PM, Hubert Kario wrote:

On Monday 27 of June 2011 11:04:06 Proskurin Kirill wrote:

quoted

Hello all.

What we have:
SL6 - kernel 2.6.32-131.2.1.el6.x86_64
btrfs on mdadm RAID5 with 8 HDD - 27T partition.

I see this at top:
1182 root      20   0     0    0    0 R 100.0  0.0  16:39.73
[btrfs-delalloc-]

And LA is grow. What is this and how can I fix it?

delalloc is a delayed allocation kernel thread -- it probably means something
is writing large amounts of data to the file system

2.6.32 is *old* as far as btrfs is concerned, there have been many bugs fixed
and performance improvements since

Ok - I upgrade to 2.6.39-2 but it is seems to all things get worse.
Now I see [btrfs-transacti] & btrfs-endio-wri] 80-100% all the time and 
io performance looks like lower then before.

Our scribe daemon in state D most of the time with half of a normal 
load. Only kernel was changed.

Any performance tune recommendation?

-- 
Best regards,
Proskurin Kirill