Adding hard disk to Software RAID after crash

rajesh.bahl · 01-02-2009, 07:39 AM

Dear All,

Hello ! My system is running on CentOS 5.2. There were two hard disks running on software RAID level 1. One of the hard disks (IDE) crashed. The system is still running.I have added a new hard disk in the system.

How can I configure it in software RAID so that it becomes exact mirror of the existing disk ?

Thanks In Advance

avijitp · 01-02-2009, 08:28 AM

Check your current /etc/raidtab

Code:

cat /etc/raidtab

       raiddev /dev/md0
           raid-level              1
           nr-raid-disks           2
           persistent-superblock   0
           chunk-size              8

           device                  /dev/hda1
           raid-disk               0
           device                  /dev/hdb1
           raid-disk               1

You should be able to see your current raid configuration and the device. If the replaced hard drive has been detected as the same device, just the 'raidhostadd'

Code:

raidhotadd /dev/md0 /dev/hdb1

I assumed that /dev/hdb1 is your newly added disk partition.

Then use 'watch cat /proc/mdstat' to view the re-mirroring process.

Before this make sure that you have re-partioned your new hard disk same as earlier.