Extreme slowness with xfs [WAS: Re: Slowness with new pc]

[Justin Piszcz]

On Tue, 25 Nov 2008, Christoph Hellwig wrote:

> On Tue, Nov 25, 2008 at 04:56:24AM -0500, Justin Piszcz wrote:
>> barriers enabled:
>>
>> $ time bash -c 'tar xf linux-2.6.27.7.tar; sync'
>> block 573932: ** Block of NULs **
>> Total bytes read: 293857280 (281MiB, 1.9MiB/s)
>>
>> real    2m40.643s
>> user    0m0.194s
>> sys     0m1.541s
>>
>> barriers disabled:
>>
>> time bash -c 'tar xf linux-2.6.27.7.tar; sync'
>> block 573932: ** Block of NULs **
>> Total bytes read: 293857280 (281MiB, 11MiB/s)
>>
>> real    0m27.612s
>> user    0m0.182s
>> sys     0m1.617s
>
> That's worse than usual, and even the no-barriers numbers are still
> really bad.  What kind of disk and controller is this?  Did you
> try to disable the cache with hdparm and see what that gives?
>

WD 750G on ICH7

Device Model:     WDC WD7500AAKS-00RBA0
00:1f.2 SATA controller: Intel Corporation 82801GR/GH (ICH7 Family) SATA 
AHCI Controller (rev 01)

I've not tried playing with the cache.

Justin.