Jeff Kennedy asked:

A quick question regarding NetApp filer clustering.

How well does it work?

Would you spend the money again?

Problems you've encountered that make it of questionable value.

The website I admin has a clustered pair of 760's. The site has had to run production on one filer head only once that I can recall, when a shelf controller in one fibre loop failed. No performance difference was noticeable; all mac address/ip failovers have worked correctly under the revs of OnTap that've been on those boxes.

One nice thing is that if you need to reboot a filer to clear a hung ndmp process or release a busy snapshot, you just fail over and then 'give back'. Downtime for the filer entity that's moving is somewhere under 15 seconds, I think, mounts hang briefly and then come right back. (All nfs mounts are either hard or under automountd control, solaris 2.6/8)

I can't speak for CIFS problems, the windows guys here are all emc fans. But I've been pushing for clustering on the 740's forever: The extra level of redundancy is worth the $ for peace of mind.

The only cluster-related problem I've had to deal with was before I learned about the contents of etc/disk_fw. A disk with no corresponding up-to-date bin file caused both fibre loops to time out and halt their heads. Seems fair, it's a hardware thing, and both filers _are_ directly connected to both sets of disk shelves.

Dave Toal unix person Thomson & Thomson

"Link, Bill (OTS-EDH)" wrote:

We run an 840c cluster with 3TB of storage as part of an AIX HACMP cluster. Prior to that the filer heads were 760's. Although we have had no failures to speak of, during testing we deliberately failed everything from the host rs6000 systems to the filer heads including all network hardware without a problem. (Well, we did have a problem with nfs timeouts during cluster failover because the application couldn't handle the error but we fixed that by making the nfs mounts hard.)

Bill Link System Administrator DST Output inc. bill_link@billing.com

-----Original Message----- From: Jeff Kennedy [mailto:jlkennedy@amcc.com] Sent: Monday, March 04, 2002 7:05 AM To: NDMP List Subject: clustering filers

A quick question regarding NetApp filer clutering.

How well does it work?

Would you spend the money again?

Problems you've encountered that make it of questionable value.

We are putting more and more applications on the filer that are considered 24X7 when the filer itself is not. Granted, they are extremely reliable but the fact is that they have several single points of failure. I am looking at clustering filers as a way of fixing that. The other possibility is Veritas ServPoint HA on SAN.

Thanks.

===================== Jeff Kennedy Unix Administrator AMCC jlkennedy@amcc.com

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