Did you notice: Rebuild Status : 0% complete Do this: cat /proc/mdstat Guy -----Original Message----- From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid-owner@xxxxxxxxxxxxxxx] On Behalf Of David Greaves Sent: Thursday, June 03, 2004 10:30 AM To: linux-raid@xxxxxxxxxxxxxxx Subject: Raid 5 questions Hi I've perused the archives and read the docs but I'm not sure on this point :) If I create an array with 3 250Gb disks and use the 'missing' option I should get a degraded raid5 array with 750Gb Now, when another 250Gb disk arrives I want to add that as the missing disk - will that work? Now, since I actually have the 3 disks and I'm waiting for the 4th, lets try it with 2 and add a third... Clear out the superblocks so we're starting from scratch cu:~# mdadm --stop /dev/md0 cu:~# mdadm --zero-superblock /dev/sda cu:~# mdadm --zero-superblock /dev/sdb cu:~# mdadm --zero-superblock /dev/sdc Make the array. cu:~# mdadm -v -C /dev/md0 --chunk=128 --level=5 --raid-devices=3 /dev/sda /dev/sdb missing mdadm: layout defaults to left-symmetric mdadm: size set to 245117312K mdadm: array /dev/md0 started. What have we got? cu:~# mdadm --detail /dev/md0 /dev/md0: Version : 00.90.01 Creation Time : Thu Jun 3 16:19:26 2004 Raid Level : raid5 Array Size : 490234624 (467.52 GiB 502.00 GB) Device Size : 245117312 (233.76 GiB 251.00 GB) Raid Devices : 3 Total Devices : 2 Preferred Minor : 0 Persistence : Superblock is persistent Update Time : Thu Jun 3 16:19:26 2004 State : clean, no-errors Active Devices : 2 Working Devices : 2 Failed Devices : 0 Spare Devices : 0 Layout : left-symmetric Chunk Size : 128K Number Major Minor RaidDevice State 0 8 0 0 active sync /dev/sda 1 8 16 1 active sync /dev/sdb 2 0 0 -1 removed UUID : 8acbe990:b31287f7:32888f7d:f0edcf0c Events : 0.3887 Thats 2x 251Gb giving a 502Gb array - good Add this to the config cu:~# echo 'DEVICE /dev/sd[abcd]' >/etc/mdadm/mdadm.conf cu:~# mdadm --detail --scan >>/etc/mdadm/mdadm.conf cu:~# cat /etc/mdadm/mdadm.conf DEVICE /dev/sd[abcd] ARRAY /dev/md0 level=raid5 num-devices=3 UUID=8acbe990:b31287f7:32888f7d:f0edcf0c devices=/dev/sda,/dev/sdb Now, the new disk arrives... cu:~# mdadm /dev/md0 -a /dev/sdc mdadm: hot added /dev/sdc So it should be working fine... cu:~# mdadm --detail /dev/md0 /dev/md0: Version : 00.90.01 Creation Time : Thu Jun 3 16:19:26 2004 Raid Level : raid5 Array Size : 490234624 (467.52 GiB 502.00 GB) Device Size : 245117312 (233.76 GiB 251.00 GB) Raid Devices : 3 Total Devices : 3 Preferred Minor : 0 Persistence : Superblock is persistent Update Time : Thu Jun 3 16:23:21 2004 State : clean, no-errors Active Devices : 2 Working Devices : 3 Failed Devices : 0 Spare Devices : 1 Layout : left-symmetric Chunk Size : 128K Rebuild Status : 0% complete Number Major Minor RaidDevice State 0 8 0 0 active sync /dev/sda 1 8 16 1 active sync /dev/sdb 2 0 0 -1 removed 3 8 32 2 spare /dev/sdc UUID : 8acbe990:b31287f7:32888f7d:f0edcf0c Events : 0.3888 Nope it's a spare? Help - how do I make my array resilient? Environment: Debian testing Linux cu.dgreaves.com 2.6.6 #1 Thu Jun 3 14:12:01 BST 2004 i686 GNU/Linux mdadm - v1.5.0 - 22 Jan 2004 Thanks David - 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
