On Wed, Nov 11, 2009 at 09:05:20PM +0000, Richard W.M. Jones wrote: > On Wed, Nov 11, 2009 at 01:24:20PM -0600, Eric Sandeen wrote: > > Anybody got actual numbers? I don't disagree that mkfs.ext4 is slow in > > the default config, but I don't think it should be slower than mkfs.ext3 > > for the same sized disks. > > Easy with guestfish: > > $ guestfish --version > guestfish 1.0.78 > $ for fs in ext2 ext3 ext4 xfs jfs ; do guestfish sparse /tmp/test.img 10G : run : echo $fs : sfdiskM /dev/sda , : time mkfs $fs /dev/sda1 ; done > ext2 > elapsed time: 5.21 seconds > ext3 > elapsed time: 7.87 seconds > ext4 > elapsed time: 6.10 seconds > xfs > elapsed time: 0.45 seconds > jfs > elapsed time: 0.78 seconds > > Note that because this is using a sparsely allocated disk each write > to the virtual disk is very slow. Change 'sparse' to 'alloc' to test > this with a non-sparse file-backed disk. You really want to avoid using sparse files at all when doing any kind of benchmark / performance tests in VMs. The combo of a sparse file store on a journalling filesystem in the host, w/ virt can cause very pathelogically bad I/O performance until the file has all its extents fully allocated on the host FS. So the use of a sparse file may well be exagarating the real difference in elapsed time between these different mkfs calls in the guest. Regards, Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :| -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
