On Thu, Nov 12, 2009 at 09:54:12AM +0000, Daniel P. Berrange wrote: > 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. Again, this time backed by a 10 GB logical volume in the host, so this should remove pretty much all host effects: $ for fs in ext2 ext3 ext4 xfs jfs reiserfs nilfs2 ntfs msdos btrfs hfs hfsplus gfs gfs2 ; do guestfish add /dev/mapper/vg_trick-Temp : run : zero /dev/sda : echo $fs : sfdiskM /dev/sda , : time mkfs $fs /dev/sda1 ; doneext2 elapsed time: 3.48 seconds ext3 elapsed time: 5.45 seconds ext4 elapsed time: 5.19 seconds xfs elapsed time: 0.35 seconds jfs elapsed time: 0.66 seconds reiserfs elapsed time: 0.73 seconds nilfs2 elapsed time: 0.19 seconds ntfs elapsed time: 2.33 seconds msdos elapsed time: 0.29 seconds btrfs elapsed time: 0.16 seconds hfs elapsed time: 0.44 seconds hfsplus elapsed time: 0.46 seconds gfs elapsed time: 1.60 seconds gfs2 elapsed time: 3.98 seconds I'd like to repeat my proviso: I think this test is meaningless for most users. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into Xen guests. http://et.redhat.com/~rjones/virt-p2v -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
