How to create degraded raid6 array using megacli

There is a server with few disks. And - a new server with PERC controller.

I would like to migrate existing data into a new server to raid6 which uses 6 disks(4+2).

Unfortunly - i don't have enought free disks to create a "target" raid6 array. I would like to create a degraded raid6 array using 4 disks (which will work like a 4 disks raid0), and then after migrating data - add 2 last disks from old server into it and rebuild array.

Is that possible using megacli? I tried it using -Force option to -CfgLdAdd and pointing missing slots - but it didn't work. Is there any other way to do that job?

Solution 1:

You cannot create a new RAID in a degraded state with PERC controllers. You'll need to use drives that are "unconfigured good" and presently in the system.

I would recommend simply creating a RAID6 with the four drives that you have, then expanding with two added drives when you have them.

If you really need the full four drives of capacity to start with, you'll be stuck having to create a true RAID0. You can simply reconstruct as RAID6 while adding the two new drives in one single operation:

MegaCli64 -LDRecon -Start -r6 –Add PhysDrv[E0:S4,E0:S5] -L0 -a0

(-Lx = virtual drive number, -aN = controller number)