You need more NICs (we hit this issue all the time).

Basically, set both filers up on both networks as if they were separate filers.  Given them separate IP addresses.  If one head dies, the other head will takeover all connections and assume the "personality" of the dead filers.  So the IPs and the disks of the dead filer will all be visile on the live one.

The heads have an internal interconenct that makes this possible.

And everything Adam said about the disks.

Peta

2009/6/2 Fox, Adam <Adam.Fox@netapp.com>
You are correct that clustering is treated as two separate controllers
which can take over for each other.  You cannot vif across NICs on
different controllers.

If you want to do the closest thing to active/passive would be to
allocate at least 2 (possible 3 if you want a spare) disks to the
"passive" controller and the rest to the active one.  I'd set up a raid4
trad vol or aggregate for it since you only are going to use 2 disks,
you don't need raid_dp.  Definitely use raid_dp on the active
controller.

Under this scenario, you can lose either controller head and still be
running.

-- Adam Fox
Systems Engineer
adamfox@netapp.com

-----Original Message-----
From: Ray Van Dolson [mailto:rvandolson@esri.com]
Sent: Tuesday, June 02, 2009 11:44 AM
To: toasters@mathworks.com
Subject: FAS2050C questions (clustering)

I'm the proud new owner of an IBM N3600 A20 (rebranded FAS2050C) with
20x30GB SAS disks.

I'm trying to determine the best way to get this thing set up, and
realized I have only a bit of a fuzzy understanding as to how the
clustering or failover filer head should work.

My initial thoughts were to aim for the following setup:

 - Set up all 20 disks in a RAID-DP aggregate with one spare (17 data,
   2 parity and one spare, or maybe two spares).
 - Bond a NIC from the first controller with a NIC from the second
   controller to give us a 2Gbps connection to our "storage network".
 - Third and fourth NIC's would go to our regular network.

My hope was that I could lose one filer head and the other would take
over seamlessly.  We'd lose half of our network bandwidth but still be
up and running.

However, it sounds like my understanding of how the clustering works
might have been a bit flawed and that I actually need to treat the
filer heads as two separate filers.  So I may be forced to do something
like the following:

 - Split my disks up between the two filers (7 data, 2 parity, one
   spare -- or maybe I can have one spare available to both heads).
 - Probably can't team NIC's from multiple filer heads meaning if I
   team the two NIC's on the filer I can no longer connect to my
   management network.  I probably need to order more NIC's :(
 - If I lose one head, I lose one aggregate unless manual intervention
   is taken.
 - Each filer has a different hostname/IP for network access.

This maybe gives me better performance, but at the expense of total
disk space and flexibility if my understanding is correct.

Maybe someone could help clear this up.  It doesn't appear IBM has a
RedBook on clustering... I'm searching around in NOW and have come
across the Data ONTAP 7.3 Active/Active Configuration Guide which I am
now reading.

Is there something similar for Active/Passive setups (which seems to be
more what I am after) or other documents that would be recommended
reading?  Any advice or best practices?

This filer will be serving NFS to a pair of ESX servers.  We plan to
add a second shelf of disks later this year.

Thanks in advance.  No sales inquiries please.

Ray