[CentOS] Migrating to RAID

Thu Dec 10 23:44:40 UTC 2009
Les Mikesell <lesmikesell at gmail.com>

Matt wrote:
>>> I have CentOS 4.x installed on a single 500GB SATA drive.  Drive is
>>> about 10 percent used.  I would like to migrate to software RAID 5
>>> without reinstalling the OS.  Was thinking 3 500GB drives.  Is that
>>> possible or must I reinstall?
>> Moving to RAID-1 is going to be fairly easy.  Moving to RAID-5 or RAID-6
>> will be a good bit trickier.
> The more I hear I am thinking moving to RAID-1 would be fine.  Is
> there a basic howto somewhere for that?

I've seen a howto about converting an existing disk, but I'd do it by creating 
matching RAID1 partitions with one of the devices 'missing', then copying the 
existing data over, installing grub on the new disk, then swapping drives.  Once 
you are sure the new copy is good you can add the old partitions to the raid 
devices and let them sync up.  If your grub install turns out wrong you can 
always boot the install disk in rescue mode to fix it.

On a second thought, I'd probably install Centos 5.x on the new disk, then copy 
the old stuff back.  It's pretty late in the cycle to spend much time fixing a 
4.x system.

   Les Mikesell
    lesmikesell at gmail.com