At 13:35 -0400 24/9/07, Ross S. W. Walker wrote: >Ok, so here is the command I would use: Thanks - here are the results (tried CentOS 4.5 and RHEL5, with tests on sdb when configured as both RAID 0 and as RAID 1): >Sequential reads: >disktest -B 4k -h 1 -I BD -K 4 -p l -P T -T 300 -r /dev/sdX CentOS 4.5, RAID 0: | 2007/09/25-14:26:58 | STAT | 13944 | v1.2.8 | /dev/sdb | Total read throughput: 50249728.0B/s (47.92MB/s), IOPS 12268.0/s. | 2007/09/25-14:26:58 | END | 13944 | v1.2.8 | /dev/sdb | Test Done (Passed) CentOS 4.5, RAID 1: | 2007/09/25-14:20:06 | STAT | 13807 | v1.2.8 | /dev/sdb | Total read throughput: 44994150.4B/s (42.91MB/s), IOPS 10984.9/s. | 2007/09/25-14:20:06 | END | 13807 | v1.2.8 | /dev/sdb | Test Done (Passed) RHEL5, RAID 0: | 2007/09/25-11:07:46 | STAT | 2835 | v1.2.8 | /dev/sdb | Total read throughput: 2405171.2B/s (2.29MB/s), IOPS 587.2/s. | 2007/09/25-11:07:46 | END | 2835 | v1.2.8 | /dev/sdb | Test Done (Passed) RHEL5, RAID 1: | 2007/09/25-11:35:53 | STAT | 3022 | v1.2.8 | /dev/sdb | Total read throughput: 2461696.0B/s (2.35MB/s), IOPS 601.0/s. | 2007/09/25-11:35:53 | END | 3022 | v1.2.8 | /dev/sdb | Test Done (Passed) >Sequential writes: >disktest -B 4k -h 1 -I BD -K 4 -p l -P T -T 300 -w /dev/sdX CentOS 4.5, RAID 0: | 2007/09/25-14:28:19 | STAT | 13951 | v1.2.8 | /dev/sdb | Total write throughput: 66150946.1B/s (63.09MB/s), IOPS 16150.1/s. | 2007/09/25-14:28:19 | END | 13951 | v1.2.8 | /dev/sdb | Test Done (Passed) CentOS 4.5, RAID 1: | 2007/09/25-14:21:52 | STAT | 13815 | v1.2.8 | /dev/sdb | Total write throughput: 53170039.5B/s (50.71MB/s), IOPS 12981.0/s. | 2007/09/25-14:21:52 | END | 13815 | v1.2.8 | /dev/sdb | Test Done (Passed) RHEL5, RAID 0: | 2007/09/25-11:13:44 | STAT | 2850 | v1.2.8 | /dev/sdb | Total write throughput: 66031616.0B/s (62.97MB/s), IOPS 16121.0/s. | 2007/09/25-11:13:44 | END | 2850 | v1.2.8 | /dev/sdb | Test Done (Passed) RHEL5, RAID 1: | 2007/09/25-11:36:36 | STAT | 3031 | v1.2.8 | /dev/sdb | Total write throughput: 56870229.3B/s (54.24MB/s), IOPS 13884.3/s. | 2007/09/25-11:36:36 | END | 3031 | v1.2.8 | /dev/sdb | Test Done (Passed) >Random reads: >disktest -B 4k -h 1 -I BD -K 4 -p r -P T -T 300 -r /dev/sdX CentOS 4.5, RAID 0: | 2007/09/25-14:28:59 | STAT | 13958 | v1.2.8 | /dev/sdb | Total read throughput: 504217.6B/s (0.48MB/s), IOPS 123.1/s. | 2007/09/25-14:28:59 | END | 13958 | v1.2.8 | /dev/sdb | Test Done (Passed) CentOS 4.5, RAID 1: | 2007/09/25-14:23:14 | STAT | 13822 | v1.2.8 | /dev/sdb | Total read throughput: 549570.2B/s (0.52MB/s), IOPS 134.2/s. | 2007/09/25-14:23:14 | END | 13822 | v1.2.8 | /dev/sdb | Test Done (Passed) RHEL5, RAID 0: | 2007/09/25-11:16:21 | STAT | 2875 | v1.2.8 | /dev/sdb | Total read throughput: 273612.8B/s (0.26MB/s), IOPS 66.8/s. | 2007/09/25-11:16:21 | END | 2875 | v1.2.8 | /dev/sdb | Test Done (Passed) RHEL5, RAID 1: | 2007/09/25-11:39:20 | STAT | 3042 | v1.2.8 | /dev/sdb | Total read throughput: 546816.0B/s (0.52MB/s), IOPS 133.5/s. | 2007/09/25-11:39:20 | END | 3042 | v1.2.8 | /dev/sdb | Test Done (Passed) >Random writes: >disktest -B 4k -h 1 -I BD -K 4 -p r -P T -T 300 -w /dev/sdX CentOS 4.5, RAID 0: | 2007/09/25-14:29:34 | STAT | 13965 | v1.2.8 | /dev/sdb | Total write throughput: 1379532.8B/s (1.32MB/s), IOPS 336.8/s. | 2007/09/25-14:29:34 | END | 13965 | v1.2.8 | /dev/sdb | Test Done (Passed) CentOS 4.5, RAID 1: | 2007/09/25-14:24:15 | STAT | 13829 | v1.2.8 | /dev/sdb | Total write throughput: 782199.5B/s (0.75MB/s), IOPS 191.0/s. | 2007/09/25-14:24:15 | END | 13829 | v1.2.8 | /dev/sdb | Test Done (Passed) RHEL5, RAID 0: | 2007/09/25-11:19:21 | STAT | 2894 | v1.2.8 | /dev/sdb | Total write throughput: 1377894.4B/s (1.31MB/s), IOPS 336.4/s. | 2007/09/25-11:19:21 | END | 2894 | v1.2.8 | /dev/sdb | Test Done (Passed) RHEL5 RAID 1: | 2007/09/25-11:40:08 | STAT | 3049 | v1.2.8 | /dev/sdb | Total write throughput: 798310.4B/s (0.76MB/s), IOPS 194.9/s. | 2007/09/25-11:40:08 | END | 3049 | v1.2.8 | /dev/sdb | Test Done (Passed) I'm not sure what to make of it, mind you. Cheers S.