> copying chunks of a few MBs seems to always beat copying > > bytes or KB per chunk. > What kind of RAID? Anything that involves parity is going to require > small writes to read and merge the new data into blocks and rewrite > the parity. At least mdadm RAID1 and RAID5. Hardware raid5 was slow with 512, but not yet tested with 4096 or higher. I'll test it in a few days after a migration completes. -- 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 On Fri, 24 Feb 2012 09:57:30 -0600 Les Mikesell <lesmikesell@gmail.com> wrote: > On Thu, Feb 23, 2012 at 10:46 AM, Ray Morris <support@bettercgi.com> > wrote: > > 512 byte sector consumer SATA drives from Seagate and Hitachi. > > Drives attached to a 9560 RAID card exhibited more difference than > > drives in a different system attached to the motherboard directly. > > As I mentioned, I haven't done extensive or highly scientific > > testing, but in general, across various hardware using various > > software, copying chinks of a few MBs seems to always beat copying > > bytes or KB per chunk. > > > What kind of RAID? Anything that involves parity is going to require > small writes to read and merge the new data into blocks and rewrite > the parity. > _______________________________________________ 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/
