[CentOS] Migrating to RAID

[Matt]

>>>> 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.

I am thinking that way too.  Even though everything is running
perfectly fine on 32bit 4.x right now moving too 64bit 5.x would be
much better.  Was thinking upgrading to RAID1 would let me wait and do
that at my leisure though.  Reinstalling and moving all this too 5.x
is no small task though.  Yuk.

Matt