This was likely a problem with the speed setting and not the mixing of ESH2 and ESH4. I've run loops with ESH2 and ESH4 together without problems. The speed settings need to be the same, though. Also, Netapp recommends that the ESH4 boards be on the "outside" of the loop (the way you are planning on adding them, actually).

If you are putting together a long or full loop, make sure you are on the latest versions of the ESH4 firmware. One of them had a serious issue which made long loops time out.

Fred

From: Steve Losen <scl@sasha.acc.virginia.edu>
To: toasters@mathworks.com
Sent: Thu, June 24, 2010 7:48:16 AM
Subject: DS14MK2 and DS14MK4 shelves on same chain?

Hello Toasters,

We had a downtime on a FAS6040 clustered pair to add Ethernet
cards and add two new shelves of FC disks.  I had to rearrange
the cabling of the shelf chains because the new shelves could
not be installed next to the "tail" shelves on the chains.

The 6040s would not boot up because the aggr containing the
root volume was incomplete.  The shelf lights indicated a
problem with the chains I had worked on.

While inspecting my cabling, I noticed (for the first time) that
the new shelves are ESH4 while the old selves are all ESH2.  I also
noticed that the ESH4 shelves are set to 4Gbit speed while the ESH2s
are 2Gbit.

Not knowing if I can mix ESH2 and ESH4, I disconnected the new shelves
in such a way that they can be "hot added" later to the tails of
the chains.  Then the filers booted up fine.

Question:

Can I hot add the ESH4 shelves to the ESH2
 chains if I set the speed
to 2Gbit?  Or must ESH4 shelves be on a separate chain?  All disks
are FC, I am not trying to mix SATA and FC shelves.

Steve Losen   scl@virginia.edu    phone: 434-924-0640

University of Virginia               ITC Unix Support