I spent a bit of today RAIDing through the internets and digging for RAID info.
Specifically what I want to do is upgrade the physical disks on my RAID array.
Unfortunately, I can only have 2 physical disks, and both are used by my RAID setup, which mirrors data.
So I sorted through some Google posts on RAID. RAIDing through all the various RAID information, I found a post that was concentrating on a larger array, and one which wasn’t a system drive.
But it was in some sense, useful. The suggestions they had were, adding the larger drives, and letting them rebuild, do it for set A, then set B.
Once you have that rebuild, keep the process moving with other disks.
That doesn’t work 100%, because when you have a RAID disk, the RAID controller configures the logical drive sizing.
In the case of non system drives, you would upgrade the drive to the larger disk, the RAID controller should hopefully already use the full extent of the Physical drive, and extend the logical drive (or do this yourself), then, you would just use your operating system to extend the partition to span the full drive.
In the case of system drives though, that are hosting the OS as well.
You are essentially required to reinstall.
At least, I thought so.
I imagine you could instead, do a GHOST between drives. Split your RAID out of mirroring, go into single mode.
Once in single mode, add your second SCSI disk.
With the SCSI disk in place, ghost the partition over.
Use partition tools to resize the partition outside of the operating system.
Viola, one parent drive done.
Plug that in, remove the other drive.
Add your second mirror drive.
Configure your controller to enter into mirroring mode again.
Start a rebuild of the second drive in your array.
And that should be it.
Keep the other two drives as backups of the data at that point.
All sounds good in theory right? Low downtime (the copy operation might take a bit), and safe enough to avoid any reinstall issues.