Create SW RAID from disks which were in HW RAID ARRAY

When i built my new server, i got disks from old server.

In old server was HW RAID array and the new server doesn’t supports HW RAID.

So, i boot sysrescue CD on server and when i built new raid array i saw this message:

mdadm: device /dev/sda not suitable for any style of array

Unfortunately systemrescue want create hw raid, because he see some flags in old disk.

$ dmsetup status

shows some hw arrays.

You can remove all hw raids with

$ dmsetup remove_all

but, after the restart system see only hw raid in degrade mode, because hw raid looks like one disk.

How i can repair it?

You must remove some blocks in the end of partition, where is info about HW RAID.

For example:

1, show your disk capacity in sectors

fdisk -lu /dev/sda

Disk /dev/sda5: 20.3 GB, 20341085184 bytes
255 heads, 63 sectors/track, 2472 cylinders, total 39728682 sectors
Units = sectors of 1 * 512 = 512 bytes

2, and then you can remove last 10MB blocks where are information about HW RAID

$ dd if=/dev/zero of=/dev/sda bs=512 seek=39718442

After build array and reboot system you don’t see any hw raid device in

$ dmsetup status

and then you will see nothing and problem with

mdadm: device /dev/sda not suitable for any style of array

is gone…

That’s all