Migrate a RAID 1+0 array to RAID 0

[David Bartley]

Hi, my development department want to utilise the space currently used by the RAID 1+0 mirror on their server.

My question is would this migration be data destructive?
We have full backups of the data, but I would prefere to do this overnight and have the data and space available early morning rather than have to restore when I get in!

[Bernhard Mueller]

David,

though you do not specify which type of array you have, basically *any* true hardware RAID system has LUNs that are either fixed (RAID-1, RAID-5, or other) or internally managed (HP AutoRaid 12H or VA 7xxx family).

So to move across RAID levels you would need to rebuild the LUNs, which is a destructive action.

Only if you have space left on your array you could e.g.
create a RAID-0 LUN
use software (LVM) mirroring to mirror a RAID-1 LUN to the new RAID-0 LUN
remove mirror from RAID-1 LUN
destroy RAID-1 LUN to build new LUN for next "mirror and destroy" step.

Regards,
Bernhard

[Bernhard Mueller]

David,

of course you could also do software mirroring to any other disk (not on the array) to perform the task.

Prerequisites would be MirrorDisk license for HP-UX, or similar for other OS, plus at least the amount of disk space that one of your LUN holds. If they vary considerably in size and your free disk space is limited you would have to make a detailed plan what could be mirrored where at which time.

Regards
Bernhard