[Sunhelp] SSA 112

[Magnus Abrante]

+---+
|   | <--- supposed to be a disk
+---+


If you have RAID 0+1 you create some RAID 0 volumes and then mirror between
them:

+---+                +---+
|   |                |   |
+---+                +---+
|   | <-- RAID 1 --> |   |
+---+                +---+
|   |                |   |
+---+                +---+
RAID 0               RAID 0

--

In RAID 1+0 however, you mirror on disk level instead of volume level, and
then RAID 0 the mirrors(well, kind of).

+---+                +---+
|   | <-- RAID 1 --> |   |
+---+                +---+
|   | <-- RAID 1 --> |   |
+---+                +---+
|   | <-- RAID 1 --> |   |
+---+                +---+
RAID 0               RAID 0

Basicly RAID 1+0 is more secure, since you dont loose an entire RAID 0
in case of a disk failure, you really want this if you are mirroring
big RAID 0's with many disks.

Disksuite and Veritas Volumemanager 3.x can handle RAID 1+0.

Humm, hope that was clear.

	//Magnus


> Hi All
> 
> Could someone please explain the difference between RAID0+1 and RAID1+0
> or is there an info I could read up about his.