Does anyone know where I can find information on how domino clustering works with SAN. Our data directory for each server is located on SAN. I may just be making it more difficult than it is. With SAN, I would assume that if one server goes down, the failover can point to the SAN??
Subject: Clustering and SAN
When you’re using Domino clustering, keep in kind that it is much different from service level clusteringlike Microsoft Cluster Service or HACMP. Domino clustering is handled at the application level and each Domino cluster node needs it’s own copy of the clustered data.
There’s an older Redbook which is still a good resource for Domino clustering. It was written for R5 but the fundamentals still apply to R6 and R7. Here’s a link to that:
Subject: Clustering and SAN
Remember that Domino knows nothing about a SAN. It is just a drive letter or mount point offered to Domino by the operating system.
So yes, you can cluster on a SAN and said cluster can failover on a SAN. We have may customers who do this.
The main issue with SAN is often performance due to configuration or capacity issues, nothing related to Domino, and an entirely different discussion.
Subject: RE: Clustering and SAN
I think the question that Mr. T really has is the same one we are facing at the planning stage : We have two clustered Domino servers for mail. Each has half the users’ mail files. When server A fails, it fails-over to Server B, and the A users get their mail on B instead. To do this, we actually have all the mail files replicated to both server A and B.
What we want to do is to remove the mail files from the directly-attached storage on the servers. We want to place only a single replica of the mail files onto a new SAN. So after a failover event, we want Server A’s users’ mail files to be accessible from its clustermate Server B. We want to avoid keeping two replicas, since the “main SAN” itself is highly available, and there is a second “mirror SAN” for disaster recovery. (We do not want to fail over to the mirror SAN though)
Can we support failover without keeping two copies on the main SAN?
Subject: Clustering and SAN
Thank you for your response. I will review the documentation. As I briefly mentioned I’m looking for detail on how clustering ‘attaches’ the SAN and if replication is still involved.
Subject: Clustering and SAN
not sure what you mean “the failover can point to the SAN”. Presumably each server has it’s own “disk” allocated on the SAN.
Subject: RE: Clustering and SAN
that is correct - each server has it’s own disk allocated on the SAN
Subject: RE: Clustering and SAN
so then I don’t understand what your concern is? Ataching to the SAN has nothing to do with clustering (from a Domino perspective). You cluster Domino servers, not the SAN disk.