faeky
Why do some systems only have md1 and md2 and others have md0, md1 and md2? How do you tell what raid partition is being used for what?
Was your system originally a sme 6.x or earlier ? If so that's why you have 3 partitions on each drive.
With a fresh install of sme7.x, the system was changed to only create 2 partitions (and that is what current wiki articles are referring to ie 2 partition arrangements).
There are a few advantages with the 2 partition sme 7.x method, so you should ideally create a full backup, install a fresh OS of sme7.5.1 and then restore form the full backup.
It's advisable to test first.
That way you will only have 2 partitions, and be able to have the advantages of sme7 eg auto rebuild of arrays under certain circumstances.
Then you can proceed to increase your hard disk size as per wiki instructions.