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Created page with "{{WIP box}} Source of this page is the [https://raid.wiki.kernel.org/index.php/Growing raid wiki] ==Adding partitions== {{Note box|due to a bug of kernel 2.6.18 which is the ..."
{{WIP box}}
Source of this page is the [https://raid.wiki.kernel.org/index.php/Growing raid wiki]
==Adding partitions==
{{Note box|due to a bug of kernel 2.6.18 which is the default kernel of Centos5 and SME Server 8.0, you can not grown a RAID6}}
When new disks are added, existing raid partitions can be grown to use the new disks. After the new disk was partitioned, the RAID level 1/4/5 array can be grown. Assuming that before growing it contains four drives in Raid5 and therefore an array of 3 drives and 1 spare drive. See this [[http://wiki.contribs.org/Raid#Hard_Drives_.E2.80.93_Raid|HowTo]] for understanding the automatic raid construction of SME Server
This is how your array looks before.
[root@smeraid5 ~]# cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4] [raid1]
md1 : '''active raid1''' sda1[0] sdb1[1] sdc1[2] sdd1[3]
104320 blocks [4/4] [UUUU]
md2 : '''active raid5''' sdd2[8](S) sdc2[2] sdb2[1] sda2[0]
72644096 blocks level 5, 256k chunk, algorithm 2 [8/8] [UUU]
for example using this command to partition the new drive
sfdisk -d /dev/sda > sfdisk_sda.output
sfdisk -f /dev/sde < sfdisk_sda.output
If you have errors about sfdisk command, you can clean the drive with the dd command. Be aware that dd is called data-destroyer, think about which partition you type.
#dd if=/dev/zero of=/dev/sdX bs=512 count=1
Now we need to add the first partition /dev/sde1 to /dev/md1
[root@smeraid5 ~]# mdadm --add /dev/md1 /dev/sde1
mdadm: added /dev/sde1
[root@smeraid5 ~]# mdadm --grow --raid-devices='''5''' /dev/md1
you can see how the array is
[root@smeraid5 ~]# mdadm --detail /dev/md1
/dev/md1:
Version : 0.90
Creation Time : Tue Oct 29 21:04:15 2013
Raid Level : raid1
Array Size : 104320 (101.89 MiB 106.82 MB)
Used Dev Size : 104320 (101.89 MiB 106.82 MB)
Raid Devices : 5
Total Devices : 5
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Tue Oct 29 21:39:00 2013
State : clean
Active Devices : 5
Working Devices : 5
Failed Devices : 0
Spare Devices : 0
UUID : 15eb70b1:3d0293bb:f3c49d70:6fc5aa4d
Events : 0.4
Number Major Minor RaidDevice State
0 8 1 0 active sync /dev/sda1
1 8 17 1 active sync /dev/sdb1
2 8 33 2 active sync /dev/sdc1
3 8 49 3 active sync /dev/sdd1
4 8 65 4 active sync /dev/sde1
After that we have to do the same thing with the md2 which is a raid5 array.
[root@smeraid5 ~]# mdadm --add /dev/md2 /dev/sdj2
mdadm: added /dev/sdj2
[root@smeraid5 ~]# mdadm --grow --raid-devices='''4''' /dev/md2
mdadm: Need to backup 14336K of critical section..
mdadm: ... critical section passed.
{{Tip box| For md2 you have to keep --raid-devices='''4''' if you want to have an array of 4 drives+1spare, if you want no spare set --raid-devices='''5'''}}
Source of this page is the [https://raid.wiki.kernel.org/index.php/Growing raid wiki]
==Adding partitions==
{{Note box|due to a bug of kernel 2.6.18 which is the default kernel of Centos5 and SME Server 8.0, you can not grown a RAID6}}
When new disks are added, existing raid partitions can be grown to use the new disks. After the new disk was partitioned, the RAID level 1/4/5 array can be grown. Assuming that before growing it contains four drives in Raid5 and therefore an array of 3 drives and 1 spare drive. See this [[http://wiki.contribs.org/Raid#Hard_Drives_.E2.80.93_Raid|HowTo]] for understanding the automatic raid construction of SME Server
This is how your array looks before.
[root@smeraid5 ~]# cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4] [raid1]
md1 : '''active raid1''' sda1[0] sdb1[1] sdc1[2] sdd1[3]
104320 blocks [4/4] [UUUU]
md2 : '''active raid5''' sdd2[8](S) sdc2[2] sdb2[1] sda2[0]
72644096 blocks level 5, 256k chunk, algorithm 2 [8/8] [UUU]
for example using this command to partition the new drive
sfdisk -d /dev/sda > sfdisk_sda.output
sfdisk -f /dev/sde < sfdisk_sda.output
If you have errors about sfdisk command, you can clean the drive with the dd command. Be aware that dd is called data-destroyer, think about which partition you type.
#dd if=/dev/zero of=/dev/sdX bs=512 count=1
Now we need to add the first partition /dev/sde1 to /dev/md1
[root@smeraid5 ~]# mdadm --add /dev/md1 /dev/sde1
mdadm: added /dev/sde1
[root@smeraid5 ~]# mdadm --grow --raid-devices='''5''' /dev/md1
you can see how the array is
[root@smeraid5 ~]# mdadm --detail /dev/md1
/dev/md1:
Version : 0.90
Creation Time : Tue Oct 29 21:04:15 2013
Raid Level : raid1
Array Size : 104320 (101.89 MiB 106.82 MB)
Used Dev Size : 104320 (101.89 MiB 106.82 MB)
Raid Devices : 5
Total Devices : 5
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Tue Oct 29 21:39:00 2013
State : clean
Active Devices : 5
Working Devices : 5
Failed Devices : 0
Spare Devices : 0
UUID : 15eb70b1:3d0293bb:f3c49d70:6fc5aa4d
Events : 0.4
Number Major Minor RaidDevice State
0 8 1 0 active sync /dev/sda1
1 8 17 1 active sync /dev/sdb1
2 8 33 2 active sync /dev/sdc1
3 8 49 3 active sync /dev/sdd1
4 8 65 4 active sync /dev/sde1
After that we have to do the same thing with the md2 which is a raid5 array.
[root@smeraid5 ~]# mdadm --add /dev/md2 /dev/sdj2
mdadm: added /dev/sdj2
[root@smeraid5 ~]# mdadm --grow --raid-devices='''4''' /dev/md2
mdadm: Need to backup 14336K of critical section..
mdadm: ... critical section passed.
{{Tip box| For md2 you have to keep --raid-devices='''4''' if you want to have an array of 4 drives+1spare, if you want no spare set --raid-devices='''5'''}}