Pardon me if my assumption was incorrect, but I was under the belief that when using software RAID1, that when reads occurred on the RAID device that it would read from both drives in a striped fashion similar to how RAID0 works to improve the speed of the md devices. I am actually seeing this, but it appears that the reads on each drive are continuing for 10 to 20 seconds before moving onto the next drive and then another 10-20 seconds and back again. This is not allowing for any performance increase, it just lets the drives rest alternately. This link http://www.whine.com/~andrew/alternating_disk.png is a gkrellm snapshot of the activity, hda and hde are the two disks in the RAID array. Each disk is the master on it's own channel. I also included the mdadm --query --detail info below for each RAID partition how:~# mdadm --query --detail /dev/md/1 /dev/md/1: Version : 00.90.00 Creation Time : Sat Jul 19 08:30:42 2003 Raid Level : raid1 Array Size : 62400 (60.94 MiB 63.90 MB) Device Size : 62400 (60.94 MiB 63.90 MB) Raid Devices : 2 Total Devices : 2 Preferred Minor : 1 Persistence : Superblock is persistent Update Time : Mon Sep 15 08:41:38 2003 State : dirty, no-errors Active Devices : 2 Working Devices : 2 Failed Devices : 0 Spare Devices : 0 Number Major Minor RaidDevice State 0 3 1 0 active sync /dev/ide/host0/bus0/target0/lun0/part1 1 33 1 1 active sync /dev/ide/host2/bus0/target0/lun0/part1 UUID : faa4b7b2:4832fae8:ac2fa294:2fce1d85 Events : 0.38 how:~# mdadm --query --detail /dev/md/2 /dev/md/2: Version : 00.90.00 Creation Time : Sat Jul 19 08:32:18 2003 Raid Level : raid1 Array Size : 119140544 (113.62 GiB 121.100 GB) Device Size : 119140544 (113.62 GiB 121.100 GB) Raid Devices : 2 Total Devices : 2 Preferred Minor : 2 Persistence : Superblock is persistent Update Time : Mon Sep 15 08:41:38 2003 State : dirty, no-errors Active Devices : 2 Working Devices : 2 Failed Devices : 0 Spare Devices : 0 Number Major Minor RaidDevice State 0 3 2 0 active sync /dev/ide/host0/bus0/target0/lun0/part2 1 33 2 1 active sync /dev/ide/host2/bus0/target0/lun0/part2 UUID : 0ad35f02:56a32094:c8301e3e:45895c16 Events : 0.38 how:~# mdadm --query --detail /dev/md/3 /dev/md/3: Version : 00.90.00 Creation Time : Sat Jul 19 08:31:37 2003 Raid Level : raid1 Array Size : 499904 (488.19 MiB 511.90 MB) Device Size : 499904 (488.19 MiB 511.90 MB) Raid Devices : 2 Total Devices : 2 Preferred Minor : 3 Persistence : Superblock is persistent Update Time : Mon Sep 15 08:41:38 2003 State : dirty, no-errors Active Devices : 2 Working Devices : 2 Failed Devices : 0 Spare Devices : 0 Number Major Minor RaidDevice State 0 3 3 0 active sync /dev/ide/host0/bus0/target0/lun0/part3 1 33 3 1 active sync /dev/ide/host2/bus0/target0/lun0/part3 UUID : f8b2d95b:93055c43:d78427ac:197a610f Events : 0.38 how:~# df -h Filesystem Size Used Avail Use% Mounted on /dev/md/2 112G 94G 16G 86% / /dev/md/1 60M 16M 42M 28% /boot Have I configured something incorrectly? Or is this really the way RAID1 works? Thanks Andrew -- Andrew Herdman andrew@whine.com - Primary E-Mail - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
