lkml.org 
[lkml]   [2003]   [Nov]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: RAID-0 read perf. decrease after 2.4.20
From
Date
On Mon, 2003-11-24 at 02:05, Martin Knoblauch wrote:
> >Hello All!
> >
> >Has anyone else experienced a drastic drop in read performance on
> >software
> >RAID-0 with post 2.4.20 kernels? We have a few Athlon XP's here at our
> >lab with double IDE disks on different channels set up as RAID-0. Some
> >bonnie++ benchmark results with various kernels, on the same machine
> >(Athlon XP 2400+, 2 GHz, 1.5 GB RAM, VIA chipset, 2*Maxtor 120 GB
> >6Y060L0):
> >write read
> >2.4.20-ac1: 88,000 135,000 K/sec
> >2.4.21-pre7: 93,000 75,000
> >2.4.22-ac4: 94,000 82,000
>
> Hi,
>
> I can attest a similar drop in read performance on a IA64 box going
> from a 2.4.19ish kernel to 2.4.22. In our setup the RAID0 is LVM, not
> MD.The RAID is used a a scratch device for a out-of-core finite element
> program (NASTRAN).
>
> The setup is some 20 disks on 4 controllers. "iozone" read/reread
> Performance went from about 400MB/sec to 260 MB/sec, while write went
> up a notch. Unfortunatelly the read performance is more important for
> the application in question.
>
> Due to the fact that I have no controll over the use of the system I
> cannot make any experiments to find out what killed performance. Sorry
> :-(
>
> Martin
>
> =====
> ------------------------------------------------------
> Martin Knoblauch
> email: knobi@knobisoft.de or knobi@rocketmail.com
> www: http://www.knobisoft.de
>
>

And this isn't the read-ahead size change thing?

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

\
 
 \ /
  Last update: 2005-03-22 13:58    [from the cache]
©2003-2011 Jasper Spaans