In general, disk performance on a domU will always be lower than on a dom0. That being said, I agree with Christopher that is sounds like you are using a sparse disk file. Did you create this VM with virt-install? If so, you can pass the --nonsparse option to virt-install when creating the VM to allocate all the disk space when creating the VM. Matt -- Mathew S. McCarrell Clarkson University '10 mccarrms at gmail.com mccarrms at clarkson.edu On Wed, May 20, 2009 at 12:35 PM, Francisco Pérez <fperez.x at gmail.com>wrote: > LVM on dom0 or domu? > > 2009/5/20 Christopher G. Stach II <cgs at ldsys.net> > > ----- "Francisco Pérez" <fperez.x at gmail.com> wrote: >> >> > I guess the bad performance it goes with the writing. For example on >> > decompression of a big tar.gz, installing rpm packages. Also on >> > restoring a MySQL Database... >> > >> > The first clue when i knew that something were wrong was on the FS >> > formating stage. It took really long time to format 40 GB to ext3. I >> > did the same on other machine with a sata disk... surprise! same >> > software and hardware config except for the inferior disk type and did >> > it in no time. >> >> It sounds like your the virtual disk file is sparse. If that's the case, >> you traded performance for space. It not only has to deal with the >> underlying filesystem, but it allocates the space on demand and hits that >> filesystem's journal. Try an LVM logical disk and see how that performs. >> >> -- >> Christopher G. Stach II >> >> >> _______________________________________________ >> CentOS-virt mailing list >> CentOS-virt at centos.org >> http://lists.centos.org/mailman/listinfo/centos-virt >> > > > _______________________________________________ > CentOS-virt mailing list > CentOS-virt at centos.org > http://lists.centos.org/mailman/listinfo/centos-virt > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos-virt/attachments/20090520/a0a1a1d2/attachment-0006.html>