On my system, iostat only reports since re-boot. Not since last run of iostat. I use "sar -d" for current speeds. In the past, sar has agreed with /dev/mdstat. Note, with sar -d, sectors/s are 512 bytes. Guy -----Original Message----- From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid-owner@xxxxxxxxxxxxxxx] On Behalf Of Brad Campbell Sent: Tuesday, January 11, 2005 4:48 AM To: RAID Linux Subject: "Rebuild" speed on a forced resync G'day all, Just started my big raid using mdadm --update resync to ensure the parity blocks are A-OK after a kernel panic, and I have been monitoring my Disk IO with iostat -k 5 Now this is an average for a 5 second period. I note I'm seeing about 12,456 Kilobytes/sec from each drive, but a cat /proc mdstat is giving me 6716 Kilobytes/sec. Given I'm doing a read consistency check I would expect an mdstat speed 9/10ths of my bulk per-drive read speed. (This array is sda -> sdj) Am I missing something really obvious? Kernel 2.6.10-bk10 Regards, Brad avg-cpu: %user %nice %sys %iowait %idle 39.18 0.00 60.82 0.00 0.00 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn hda 0.00 0.00 0.00 0 0 sda 97.76 12465.67 0.00 33408 0 sdb 97.76 12465.67 0.00 33408 0 sdc 97.76 12465.67 0.00 33408 0 sdd 97.76 12465.67 0.00 33408 0 sde 97.76 12465.67 0.00 33408 0 sdf 98.51 12465.67 0.00 33408 0 sdg 98.51 12465.67 0.00 33408 0 sdh 98.88 12465.67 0.00 33408 0 sdi 107.09 12465.67 0.00 33408 0 sdj 104.85 12465.67 0.00 33408 0 sdk 3.73 5.97 10.45 16 28 sdl 4.10 11.94 5.97 32 16 sdm 5.22 14.93 7.46 40 20 md0 0.00 0.00 0.00 0 0 md2 8.58 26.87 7.46 72 20 srv:/home/brad# cat /proc/mdstat Personalities : [raid0] [raid5] [raid6] md2 : active raid5 sdl[0] sdm[2] sdk[1] 488396800 blocks level 5, 128k chunk, algorithm 2 [3/3] [UUU] md0 : active raid5 sda1[0] sdj1[9] sdi1[8] sdh1[7] sdg1[6] sdf1[5] sde1[4] sdd1[3] sdc1[2] sdb1[1] 2206003968 blocks level 5, 128k chunk, algorithm 0 [10/10] [UUUUUUUUUU] [===>.................] resync = 17.4% (42765824/245111552) finish=501.9min speed=6716K/sec unused devices: <none> - 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 - 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
