Well, maybe i didn't phrase that clearly enough: that depends. It depends on a lot of things i don't know because i do not know your environment and - with all due respect - you don't seem to know either, so you can't tell me what i would need to know to explain it to you.

SDDPCM and MPIO are two different multipathing drivers, both for AIX. SDDPCM is a bit older than MPIO. You cannot just switch between them because you will need to meet certain requirements to use either of them. But this would be better discussed with someone knowing your complete setup: fabric, storage boxes, zoning, FC-switches, virtualiser, .... I would be of limited help in this capacity (and everybody else here too) because we will not have the intimate knowledge that would be required. My suggestion: go to the storage people and ask one of them to explain storage basics and their application in your specific surroundings to you.

I am terribly sorry but this is something i cannot tell you over the net with just a few forum posts. The matter is just too complex (and the single pieces too interdependent) for that.

IBM SAN Volume Controller is a storage virtualiser. It is similar in scope to i.e. EMCs VPlex product. The DS8K is a (high-end) storage box itself, which is probably managed (or maybe not - i don't know your environment) by the SVC. In principle the SVC sits between (all) the storage boxes on one side and (all) the systems using their LUNs on the other side. So, the answer to your question wether you can move the LUN from one to the other: maybe. It depends on wether the DS8k is configured to let the SVC manage the LUNs it exports or not and, again, it depends on the layout of your FC fabric and it depends on your FC switches and how they are connected and zoned and, .... You see the problem?

I hope this helps.

bakunin