Re: mdadm and UUIDs for its component drives
On Sun, Jun 26, 2011 at 11:29 AM, William Hopkins <we.hopkins@gmail.com> wrote:
>
> It seems to me that you'd be well served by simply using the UUID (by-uuid, not
> by-id) in all things, including mounting and managing. Then you would never
> need to figure out which disk sda was, you could just figure out which disk the
> UUID was (and you'd only have to learn it once).
There are UUIDs and UUIDs.
For an array md0 with sda1 and sdb1 as its components.
"blkid /dev/md0" returns the filesystem UUID.
"mdadm --detail /dev/md0" returns the mdadm UUID of the array.
"blkid /dev/sda1" returns the mdadm UUID of the array.
"mdadm --examine /dev/sda1" returns mdadm UUIDs of the array and the
partition. (I've never seen the mdadm UUID of a partition be used for
anything. Can an array be assembled by referring to an mdadm UUID of a
partition to add a partition? Would it make any sense?!)
The "/dev/disk/by-id/" symlinks are the most stable ones (for a
specific disk) should anyone want to use them because they're hardware
IDs. I don't have an mdadm'd box at hand to check but I think that
md0's entry in this directory includes the mdadm array UUID of md0
because md0 doesn't have a "real" hardware ID. So, for md0,
"/dev/disk/by-id" and "/dev/disk/by-uuid" are equivalent.
Reply to: