HP serviceguard t2808-90006 manual Adding a Mirror Component Device

Managing an MD Device

Removing and Adding an MD Mirror Component Disk

Example A-3 Removing a failed MD component disk from /dev/md0 array

To remove a failed MD component disk from /dev/md0, run the following command:

# mdadm –-remove /dev/md0 /dev/hpdev/sde

Following is an example of the status message that is displayed when a failed component is removed from the MD array:

[root@dlhct1 dev]# cat /proc/mdstat Personalities : [raid1]

md0 : active raid1 sdf[0] 9766784 blocks [2/1] [U_] unused devices: <none>

Adding a Mirror Component Device

As mentioned earlier, in certain failure scenarios, you need to remove a failed mirror disk component, repair it and then add it back into an MD array. Run the following command to add a mirror component back into the MD array:

# mdadm - -add <md device name>

<md_mirror_component_persistent_name>

Example A-4 Adding a new disk as an MD component to /dev/md0 array To add a new disk to the /dev/md0 array, run the following command:

# mdadm - -add /dev/md0 /dev/hpdev/sde

Following is an example of the status message displayed in the /proc/mdstat file once the disk is added:

Personalities : [raid1]

md0 : active raid1 sde[2] sdf[0] 9766784 blocks [2/1] [U_]

[=>	] recovery = 8.9% (871232/9766784) finish=2.7min
speed=54452K/sec
unused devices: <none>

102 Appendix A