wu shi
2008-Jun-03 07:30 UTC
[Xen-users] performance discrepancy between guest on partition and guest on file image
Hi, I am wondering if it is normal that guest created on partition is slower thatn guest created on a file(created using dd). I have created two guest using virt-install.One is on my /dev/hda5 (guest name is partition) while the other on /storage/vmdisk.img (dd if=/dev/zero of=/storage/vmdisk.img bs=1024k count=1024 )guest name is file using hdparm -tT in these two guests shows the throughput of partition is 3-5Mb/s,while the number on guest file is around 30. This discrepancy is quite huge. Is this normal? thanks _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Pasi Kärkkäinen
2008-Jun-03 07:35 UTC
Re: [Xen-users] performance discrepancy between guest on partition and guest on file image
On Tue, Jun 03, 2008 at 03:30:18PM +0800, wu shi wrote:> Hi, > I am wondering if it is normal that guest created on partition is slower > thatn guest created on a file(created using dd). > > I have created two guest using virt-install.One is on my /dev/hda5 (guest > name is partition) > while the other on /storage/vmdisk.img (dd if=/dev/zero > of=/storage/vmdisk.img bs=1024k count=1024 )guest name is file > > using hdparm -tT in these two guests shows the throughput of partition is > 3-5Mb/s,while the number on guest file is around 30. > > This discrepancy is quite huge. > Is this normal? >Possibly because of memory caching in dom0 for file based disk? -- Pasi _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users