lkml.org 
[lkml]   [2007]   [Jan]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Abysmal disk performance, how to debug?
On Sat, Jan 20, 2007 at 02:56:20PM -0500, Stephen Clark wrote:
> Sunil Naidu wrote:
>
> >On 1/20/07, Willy Tarreau <w@1wt.eu> wrote:
> >
> >
> >>It is not expected to increase write performance, but it should help
> >>you do something else during that time, or also give more responsiveness
> >>to Ctrl-C. It is possible that you have fast and slow RAM, or that your
> >>video card uses shared memory which slows down some parts of memory
> >>which are not used anymore with those parameters.
> >>
> >>
> >
> >I did test some SATA drives, am getting these value for 2.6.20-rc5:-
> >
> >[sukhoi@Typhoon ~]$ time dd if=/dev/zero of=/tmp/1GB bs=1M count=1024
> >1024+0 records in
> >1024+0 records out
> >1073741824 bytes (1.1 GB) copied, 21.0962 seconds, 50.9 MB/s
> >
> >What can you suggest here w.r.t my RAM & disk?
> >
> >
> >
> >>Willy
> >>
> >>
> >
> >Thanks,
> >
> >~Akula2
> >-
> >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/
> >
> >
> >
> Hi,
> whitebook vbi s96f core 2 duo t5600 2gb hitachi ATA HTS721060G9AT00
> using libata
> time dd if=/dev/zero of=/tmp/1GB bs=1M count=1024
> 1024+0 records in
> 1024+0 records out
> 1073741824 bytes (1.1 GB) copied, 10.0092 seconds, 107 MB/s
>
> real 0m10.196s
> user 0m0.004s
> sys 0m3.440s

You have too much RAM, it's possible that writes did not complete before
the end of your measurement. Try this instead :

$ time dd if=/dev/zero of=/tmp/1GB bs=1M count=1024 | sync

Willy

-
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: 2007-01-20 21:55    [W:0.093 / U:0.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site