Hi, When testing a soft RAID5 (8 SATA drives, Marvell chip) with iometer I noticed that the read performance did drop much less when adding randomness to the drive access as the write performance (read 80MB/s->40MB/s, write 70MB/s->9MB/s). Such a difference I can't explain by the read-compute-write of the parity stripe. I found that increasing NR_STRIPES from 256 to (8*1024) did increase the throughput for write from 9MB/s to 35 MB/s. This is still less as I would expect from 8 SATA disks in parallel. Could it be the raid5d thread is not waken up enough or has not enough priority? Anybody knows any other #defines that could help here? Bart - 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
