I have set up a software-raid 5 with mdadm on a 1.3 GHz AMD Neo 36L dual core machine using 3 1.5 TB Seagate Barracude Green drives (4k sectors). The chunk size of the raid is 512 KB. On top of the raid there is one lvm volume formatted with ext4 (Block size=4096, Stride=128 blocks, Stripe width=256 block). Both the raid and the lvm are aligned properly. When running bonnie++ I get the following results:
VVersion 1.96 ------Sequential Output------ --Sequential Input- --Random- Concurrency 1 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP 4G 362 97 69738 15 52826 16 1732 94 248671 31 539.0 32 Latency 92293us 3276ms 4274ms 22450us 38749us 111ms
Can anybody tell me if this performance is what I can expect from my setup? Especially the sequential output and the per-chr-access seems a bit too slow to me.