Recovering ASR Disks

Problem

I have some disks that used to be attached to a quasi-raid (for example: a I2O RAID Controller) that I now want to use as regular disks.

The CentOS installer sees it as a "BIOS Raid" disk, and offers to use it as /dev/mapper/asr_ something, even though there is no raid hardware or configuration.

Solution

There is a metainfo sector on the disk which has a flag that tells the OS that there's a quasi-raid going on. To get rid of this information:

# dmraid -r /dev/sda -E