suddenly slow writes on XFS Filesystem

[Stan Hoeppner]

On 5/6/2012 5:33 AM, Martin Steigerwald wrote:
> Am Sonntag, 6. Mai 2012 schrieb Stefan Priebe:
>> It is a raid 10 of 20 SATA Disks and i can only write to them with
>> about  700kb/s while doing random i/o. I tried vanilla Kernel 3.0.30
>> and 3.3.4 - no difference. Writing to another partition on another xfs
>> array works fine.
> 
> Additionally what RAID is this? SoftRAID or some - which one? - hardware 
> RAID controller? And what disks are used, whats the rpm of these?

I doubt much of this stuff matters.  Stefan's filesystem is 96% full,
w/~200GB free.  This free space is likely heavily fragmented.  If he's
doing allocation in this fragmented free space I'd think that would
fully explain his write performance dropping off a cliff due to massive
head seeking.

-- 
Stan