mdadm Cares About Partition Type

mdadm now starts caring for the partition type when creating a raid volume on partitions. It has to be 'fd' (Linux raid auto).

[used fdisk to create sda1, sda2, sdb1, sdb2. 
sda1 and sdb2's type is 82 (linux swap).
sda2 and sdb2's type is 83 (linux)]

~ $ sudo mdadm --create  /dev/md3 -n 2 -l raid1 --name='raid1 volume set' /dev/sda2 /dev/sdb2

mdadm: /dev/sda2 is too small: 0K
mdadm: create aborted



~ $ sudo mdadm --version

mdadm - v2.5.6 - 9 November 2006


[used fdisk to change sda2 and sdb2 to fd.
"Changed system type of partition 2 to fd (Linux raid autodetect)"]


~ $ sudo mdadm --create  /dev/md3 -n 2 -l raid1 --name='raid1 volume set' /dev/sda2 /dev/sdb

mdadm: array /dev/md3 started. 

(originally from http://microjet.ath.cx/WebWiki/2007.03.28_mdadm_Cares_About_Partition_Type.html)