RAID setup - change which disks are part of a unit

[stephenbrayshaw]

I have a set of Itanium i6 machines and they have come with RAID 1 out of the box.

Unlike the previous machines the RAID unit which has the OS on it has come configured as disks 1 & 8 instead of 1 & 2.

I want to change it to be 1 & 2 but without loss of data.

It is OpenVMS V8.4-2L1 & I do have the physical install media.

I did think of using msa$util with the following command but it warns about possible data corruption if the disks are mounted.

MSA> set unit 0 /expand/disk=(1,2)

Would that work if I could run msa$util from the OS Install DVD?

If not then how can I change it to be 1 & 2 without loss of data?