Where do I start… We’re finally getting budget to gear up on hardware. We have about 1400 users, 700’ish concurrent. Mainly a mail server for this hardware.
1.) Will beefy new Intel hardware (multiple p4’s and mega memory) handle Domino clustering with completely replicated mail databases? Basically, a complete failover server.
2.) If not, should any clustering, either MS or domino be used? Would it be easier to have a duplicate server that could be used to failover on either a SAN or DAS? By moving or re-mapping the storage…
Basically, I’m unclear what the preferred method of high-availability is for 1500 users with 2 physical servers. Either DAS on each server or a SAN with a shared (not at the same time) partition.
I’ve done a lot of searching, but nothing very new has shown up.
Subject: SAN & MS or Domino Clustering
Don’t go for MS clustering, use Domino clustering instead. Domino clustering will work great, but to reach optimal performance, you may need more than 2 Domino servers.Don’t worry, if you have 2 powerful servers (with at least 2 CPU’s), you can run more Domino servers on 1 box using partitioned servers (install option), or using a virtual server technology (like VMWARE)
And if you use a SAN, you can’t share the notesdata directories (well, you can using OS level clustering, but I just advised against that 
), so you do need a lot of diskspace.
So basically :
-
run 2 domino servers per intel box (with 2cpu’s)
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cluster them 1-on-1 (mail01 on first physical machine clusterd with mail02 on second physical machine,…)
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split your users between these 2 clusters.
cheers,
Tom
Subject: RE: SAN & MS or Domino Clustering
Thanks for the reply!
However, the entire point of this migration is to ensure a 24x7 operation. Wouldn’t doubling up on hardware mean introducing more possible points of failure?
Two more clarifications so I can sleep at night…
1.) If I run just 2 lotus servers, each on a quad-p4, can I use domino clustering and have one server be a primary and one have replica’s of every server on the primary? 1000 or so active mail files…
2.) Would having three beefy domino servers clustered… one as a ‘primary’ and two with half of the primary’s replica’s on it, work better?
Subject: RE: SAN & MS or Domino Clustering
Go with option 1. And if you’re going to bother clustering them, you might as well let them load balance.
Quad P4s is probably overkill, by the way.
Subject: RE: SAN & MS or Domino Clustering
You don’t double your points of failure, you reduce the risk of failure :- 1 server domino : 1 failure = 100% down
- 2 clustered domino servers : 1 failure = 50% down, but because of domino cluster, 0% downtime (well, actually users will experience a little downtime)
So you need 2 failures to reach 100% downtime (both machines at once) instead of 1 failure, that’s a reduction of 50% in chance of that happening. Which still doesn’t mean you are 100% save
Use partinioned Domino servers , to better use the hardware. You won’t have as good a performance running 1 domino server on a 4cpu box, then by running 2 or even 4 domino servers on the same box. As the other poster already mentioned, 2 x 4cpu box is probably overkill.
cheers,
Tom