On 21 Feb 2007 at 21:33, Steffen Heil wrote:
[...]
> >hdparm -tT /dev/hd?
>
> /dev/hda:
> Timing cached reads: 266 MB in 2.00 seconds = 132.84 MB/sec
> Timing buffered disk reads: 144 MB in 3.01 seconds = 47.82 MB/sec
[...]
Just for curiosity: As I'd expect XEN to buffer "virtual physical reads", did 
anybody repeat the commend twice in succession? That is
hdparm -t /dev/hda
hdparm -t /dev/hda
I have made two tests here: First SLES9 without XEN (hardware RAID1, SCSI):
/dev/sda:
 Timing buffered disk reads: 182 MB in 3.03 seconds = 60.13 MB/sec
/dev/sda:
 Timing buffered disk reads: 162 MB in 3.01 seconds = 53.76 MB/sec
Then SLES10 x86_64 with XEN 3.0.2 (hardware RAID1, SAS):
/dev/sda1:
 Timing buffered disk reads: 202 MB in 3.01 seconds = 67.17 MB/sec
/dev/sda1:
 Timing buffered disk reads: 170 MB in 3.03 seconds = 56.17 MB/sec
While the performance doesn't look verby bad, I think I can get about 150MB/s 
from 
the SAS RAID without XEN. The CPUs involved were a Pentium-4 with 2.4GHz, and 
an 
Opteron at 2.6GHz.
Regards,
Ulrich
_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users