I'm building a small server for applications and made an error when I began.
I started out with (2) 10K RPM WD Raptor drives configured as a single
RAID 0 volume.
Subsequently, I added (2) 1.5 TB drives which I wanted to use part of
each drive in a RAID 10 (not sure what RAID 0+1 is) array, using the
newly added 1.5 TB drives as mirrors of the existing RAID 0 volume.
The problem is that I've already configured a lot of software on the
system and do not want to have to go through that all over again,
but I cannot seem to find a way to add 2 drives to an existing RAID 0
configuration to effectively migrate it from RAID 0 to RAID 10.
I'm scraching my head here trying to understand why this should
not be easy to do. Can someone explain?
From your question, it sounds like what you want to do is to Migrate from a two drive RAID 0 to a RAID 4 drive RAID 10. RAID level Migration and virtual drive capacity expansion depend on what RAID stack / solution you are using. Before attempting to make any changes in your RAID configuration, you should backup all critical data.
If you are using Intel ESRTII Embedded RAID on and Intel Server Board, you have several migration options. If you are using Matrix RAID or OS level RAID, there are likely no options other than to backup your data and start over. My expertise is in regard to ESRTII Embedded RAID so I will direct my comments to that RAID solution.
If you are using Embedded RAID on an Intel Server Board, you can migrate from a two drive RAID 0 to a three or four drive RAID 5. There is not an option to migrate to a RAID 10 because of the way RAID 10 drives are designed (two RAID 1 mirrors with a RAID 0 striped across them). In order to migrate to a RAID 5, you must purchase and install the RAID 5 enablement key (AXXSRAK5). Instructions for migrating raid levels is available in the RAID SW Guide at: http://download.intel.com/support/motherboards/server/sb/d29305008_raid_swg.pdf http://download.intel.com/support/motherboards/server/sb/d29305008_raid_swg.pdf.
These operations can be performed in either the BIOS Utiity or in the OS RAID Web Console 2 Utility.