Moving several terabytes of data, I was again struck by the very large difference in performance between copying data in small chunks for large chunks. After seeing larger block sizes make dd eight times faster, I tried increasing mirror_region_size in lvm.conf: pvmove with default mirror_region_size of 512: ~4-6 MB/s pvmove with increased mirror_region_size of 4096: ~22-32 MB/s Although this was somewhat unscientific testing, I'm quite curious what results others get on their hardware. The effect was most pronounced for me on a system with a 9550SX-12. I'll do some testing on a 8888ELP next week. If 4096 is OFTEN several times faster than 512, would it make sense to consider canging the default? -- Ray Morris support@bettercgi.com Strongbox - The next generation in site security: http://www.bettercgi.com/strongbox/ Throttlebox - Intelligent Bandwidth Control http://www.bettercgi.com/throttlebox/ Strongbox / Throttlebox affiliate program: http://www.bettercgi.com/affiliates/user/register.php _______________________________________________ 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/
