Please explain effect of more nodes and ports

[slink]

We have a very small deployment going on, 4 servers with 2 x 8Gb FC ports in each and the supplier has specced out a 4 node 7400 with the optional 4-port HBAs in amounting to 16 FC ports in total. The servers will be virtualisation hosts with VMs running all sorts of workloads.

I am thinking this is massive overkill and to just stick with the 8 onboard FC ports but supplier says for the price might as well get the extra HBAs and cable it all up once, which I guess might have some merit but even if this deployment expands it's likely to only be a couple of extra hosts.

Would you recommend getting the 16 total array ports and zoning up each host to 4 array ports, i.e., each host HBA port to a port from each node pair? Is there any immediate benefit to this or is it just a case of might as well?

[hdtvguy]

I agree, this is overkill. I did add the expansion ports for a small 7200 that was going with 2 hosts because we were doing direct connects and wanted over-kill on the redundancy for paths since there were no FC switches in play. Now if you never plan on growing then you could skip FC switches and go direct, the concern there is you probably want 4 HBA ports in the host so that one port hits each controller. If you have FC switches then I would run one port on the host so noes 0 and 1 and the other to 2 and 3 and you really only need 1 front end port per controller. zoned in for your size.

[slink]

OK thanks. I'm interested in the direct connects option. I am looking at a DR deployment with a 7200 2-node and just 2 host servers, unlikely to grow to any more. I was looking at using spare ports on another SAN switch to connect the fabric but if I can connect directly even better. I thought it was just for HP Virtual Connect in the Blade system? Can't find any more info about direct connect to a rack server. They would be DL360p Gen8 servers,

[slink]

ah I've just discovered point-to-point (I'm new to FC). So looks like I can just connect up the host HBAs direct to the 7200 and make sure the ports are configured for a point-to-point host connection and that should be it.

[hdtvguy]

We actually do a DR setup as well. We have 2 7200s in a remote plant, one in the main computer room the other in a building across campus. We have 2 host direct to the main 7200 and run vmware. that 7200 replicates to the other 7200 over a 1gb network and there is a single DR host attached to that 7200. We actually set up dedicated vcenters for them and implemented SRM.

The entire setup is very much overkill for them.