On Fri, 3 Jun 2011, Joe Thornber wrote: > On Thu, Jun 02, 2011 at 03:55:16PM -0400, Mikulas Patocka wrote: > > > iv) you haven't explained how the sys admin works out the correct > > > throttle value. > > > > There is no "correct" value. The "correct" value depends on how important > > is copying itself v.s. other i/o. > > So who is going to set this? Do you really have no advice for them > beyond 'there is no correct value'? I did some tests. I did some random and sequential I/O on the same disk while mirror was resynchronizing. The result is this: random read: mirror throttle / IOs per second 100% 94 75% 113 50% 127 25% 145 idle 160 sequential read: mirror throttle / throughput MB/s 100% 104 75% 118 50% 122 25% 127 idle 134 Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
