Create a 128 MB input file: cd /tmp dd if=/dev/zero of=input bs=1024k count=128 and then create a cpio file from that to various target filesystems: echo input | time cpio --quiet -o -H newc > /path/to/fs/output I created ext2, ext3, ext4, xfs and tmpfs filesystems and mounted them (all default options). All timings on baremetal, quiet machine, with a hot cache, and then averaged over three runs: tmpfs 0.77 s x 1.0 ext2 1.12 s x 1.5 xfs 1.66 s x 2.1 ext3 2.58 s x 3.4 ext4 5.59 s x 7.3 <---- You can see that ext4 seems to do significantly worse than the others. I looked at the strace of cpio and it does 512 byte writes. I'm going to try to fix that so it does larger writes, but I'm not sure if that matters (shouldn't the kernel combine these writes?) The reason I'm concentrating on cpio (instead of cp) is that it was while creating a cpio format archive that I noticed the ext4 was performing very poorly. Rich. kernel 2.6.31.1-56.fc12.x86_64 cpio-2.10-3.fc12.x86_64 -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://et.redhat.com/~rjones/virt-top -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
