At 10:04 30-7-2003 -0700, Cliff Wells wrote:
On Wed, 2003-07-30 at 02:09, Seth Mos wrote:
> At 18:31 29-7-2003 -0700, Ravi Wijayaratne wrote:
> >Hi,
> >
> >We are seeing a %15 performance drop when we move from XFS 1.1 to 1.2.
> >Here are some of our particulars:
> >We have been testing the performance of Linux-2.4.19 and XFS 1.2 with
> >NetBench.
> >We compared the performance with that of Linux-2.4.18 and XFS 1.1.
> >We have been running Samba 3.0.
>
> The only problem I know of which is not exclusive to XFS (ext3 does
this as
> well) is one on the read performance of 2.4.18 vs the 2.4.20 errata kernel.
>
> On 2.4.18-27 I get 170MB/sec read speed
> on 2.4.20-18 I get 80MB/sec read speed.
>
> the write speed stays consistent between these releases but the enormous
> drop in read speed is very strange. It appears to be present in the
> standard rh errata as well.
Try hdparm -a 512 /dev/hdx
http://marc.theaimsgroup.com/?l=linux-kernel&m=105830842018800&w=2
That's IDE. I am talking about scsi. The 3ware controller is just a scsi
controller with IDE disks, but the OS doesn't know what disks are behind
the raid container.
[root@lsnetniet root]# hdparm /dev/sda
/dev/sda:
readonly = 0 (off)
geometry = 45051/255/63, sectors = 723757824, start = 0
[root@lsnetniet root]# hdparm -tT /dev/sda
/dev/sda:
Timing buffer-cache reads: 128 MB in 0.66 seconds =193.94 MB/sec
Timing buffered disk reads: 64 MB in 1.06 seconds = 60.38 MB/sec
[root@lsnetniet root]# hdparm -a 512 /dev/sda
/dev/sda:
setting fs readahead to 512
BLKRASET failed: Invalid argument
readahead = 120 (on)
[root@lsnetniet root]# uname -a
Linux lsnetniet.coltex.nl 2.4.20-18-rh-xfs #2 SMP ma jun 23 11:01:51 CEST
2003 i686 unknown
[root@lsnetniet root]#
And thus the experiment fails.
Any other suggestions :-)
Cheers
--
Seth
It might just be your lucky day, if you only knew.
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