This I think is an reported bug. On Mon, Nov 2, 2009 at 11:58 PM, Chris Worley <worleys@xxxxxxxxx> wrote: > I expect RAID1 write performance to be, at best, the performance of > the slowest drive. > > I'm seeing twice the performance, as if it were a RAID0. The read > performance is 2x also, which is what I would expect. > > I'm using the incantation: > > mdadm --create /dev/md0 --chunk=256 --level=1 --assume-clean > --raid-devices=2 /dev/sd[bc] > > I use "assume clean" on the fresh create, as there is no reason to > sync the new drives. > > My "fio" test uses O_DIRECT with 64 threads, each with a queue depth > of 64, running for 10 minutes. All caching is disabled, and the NOOP > scheduler is being used. I run this test all the time, and can't > imagine why it's getting such repeatably good write performance. > > Any ideas? > > Thanks, > > Chris > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- -- Sujit K M blog(http://kmsujit.blogspot.com/) -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
