try bs=64k, even better... On Thu, 2004-06-10 at 08:05, Stuart Harper wrote: > While doing backups of my LVM2 drive, I've found that setting the DD block > size to 4096 greatly improved my performance. Formerly, DDs on my 240G LVM > were taking 23hrs to complete with a block size of 512 or 1024. The same > volume now takes less than 2 hours with a block size of 4096. Large numbers > did not seem to increase DD speed. > > On Thursday 10 June 2004 10:25 am, David Greaves wrote: > > 65Mb/s on the raid5 device > > 44Mb/s on the lv > > > > Is this expected? > > > > Kernel 2.6.6 > > > > representative dd's: > > > > cu:/huge/editing/tmp# time dd if=/dev/video_vg/video_lv of=/dev/null > > bs=1024k count=4k > > David > _______________________________________________ > linux-lvm mailing list > linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
