> Is it possible for you to set up a test with raid5 using a different sata > or sas interface card? I tried a Level 1 RAID on two SATA discs (on the same hardware that I did the plain-SATA test on).
Throughput to the fs is 83MB/s write, 101MB/s read. svn update takes 5,6s without WAPBL and 7s with WAPBL. The touch..rm test takes 15,1s without WAPL and 13,6s with WAPBL. Compared to plain disc on the same hardware: - FS throughput is roughly as on a plain disc, as expected. - svn update is slowed down only with WAPBL enabled. - touch..rm performs roughly equivalent (to plain disc) without WAPBL, but takes three times as long as on a plain disc with WAPBL enabled. Compared to the mpt(4) SAS Level 1 RAID: - FS write throughput is much faster as on mpt - svn update with WAPBL is twice as fast as on mpt (no difference to mpt when WAPBL is disabled) I still don't understand why writing to a RAID 1 in stripe-sized chunks could be noticebly slower than writing to the component device (as it is on my mpt(4) SAS drives).
