On Mon, May 07, 2007 at 08:41:29PM -0400, Paul Wouters wrote: > On Tue, 8 May 2007, John Summerfield wrote: > > > btw You can create sparse files in the first place: > > dd if=/dev/zero of=/tmp/ext-fs seek=$((4*1024*1024)) count=0 > > mke2fs -F -q /tmp/ext-fs > > I understood that using sparse files will significantly slow down > the xenu for the first time, as it keeps growing the fs allocation > underneath it. That is correct. Never use sparse files if you care about performance as they exhibit pathelogically bad behaviour while growing the allocation. Pre-allocation a file should give the best performance for file backed guests, as close as you'll get to native without using physical devices directly. With a little tweaking to the dd command shown above though it ought to be possible to extend the image, while allocating the data. You basically want to seek=<current end of file> and then count=<additional space> desired. Dan. -- |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=| |=- Perl modules: http://search.cpan.org/~danberr/ -=| |=- Projects: http://freshmeat.net/~danielpb/ -=| |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=| -- Fedora-xen mailing list Fedora-xen@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-xen
