If I have RAID 5 on my P4500 nodes, how is RAID 10 applied to the array's volume?

[Threxx]

I'm trying to get a better understanding of how my P4500 SAN is handling data.

I have two P4500 nodes with twelve HDDs each.
As I understand it, each of the two controllers within each node has its own RAID 5 set. So I have two RAID 5 sets per node or four RAID 5 sets within the SAN array.

So I see that as
A1 A2 A3 A4 A5 P1 A6 A7 A8 A9 A10 A11 P2
P1 B1 B2 B3 B4 B5 B6 P2 B7 B8 B9 B10 B11

etc...

Where I'm confused is when I select RAID 10 for my volume (which spans both nodes, of course). I understand that this is some unique form of RAID that HP calls network RAID. But I still don't understand how it behaves.

It seems like RAID 10 by definition would create data mirroring within each node, and then would stripe across the array. But that would mean if I lost one node, I'd lose half my data. So I'm assuming that the data is, instead, striped within each node and then mirrored between the nodes. But then isn't that by definition RAID 0+1?

P.S. This thread has been moevd from Storage Area Networks (SAN) (Enterprise) to HP StoreVirtual Storage / LeftHand. - Hp Forum Moderator

[Uwe Zessin]

When you configure a Network RAID 10 with two storage nodes, I would assume that it creates a logical mirror (just a simple RAID-1) between the nodes. If one node goes down, there is still a good copy on the remaining one.

It becomes 'interesting' with more storage nodes, because their position in the cluster defines what data is placed on it.