On Mon, 18 Jun 2007, Brendan Conoboy wrote:
david@xxxxxxx wrote:
I plan to test the different configurations.
however, if I was saturating the bus with the reconstruct how can I fire
off a dd if=/dev/zero of=/mnt/test and get ~45M/sec whild only slowing the
reconstruct to ~4M/sec?
I'm putting 10x as much data through the bus at that point, it would seem
to proove that it's not the bus that's saturated.
I am unconvinced. If you take ~1MB/s for each active drive, add in SCSI
overhead, 45M/sec seems reasonable. Have you look at a running iostat while
all this is going on? Try it out- add up the kb/s from each drive and see
how close you are to your maximum theoretical IO.
I didn't try iostat, I did look at vmstat, and there the numbers look even
worse, the bo column is ~500 for the resync by itself, but with the DD
it's ~50,000. when I get access to the box again I'll try iostat to get
more details
Also, how's your CPU utilization?
~30% of one cpu for the raid 6 thread, ~5% of one cpu for the resync
thread
David Lang
-
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
