HBA Configuration on ESXi 5 Host

[snowmizer]

I am setting up UCS blades for our ESXi 5.0 hosts. I currently have 4 ports plugged in to the UCS from our VNX (2 from SPA and 2 from SPB). I have defined the service profile on the blade to allow for 4 vHBAs. This gives me 8 paths to each LUNs. When I look at the paths available I see all 8 but only 4 are "Active (I/O)" (going to 2 specific ports on the VNX) and the rest are just "Active" (going to the remaining 2 ports on my VNX). If not all the ports to the VNX are going to be used would I be better off just configuring 2 vHBAs? I'm thinking that if I do then I'll have 4 paths but only 2 will show "Active (I/O)". This isn't what I want. I'm thinking that my current configuration will give me the best redundancy in case of any failure. Am I off base?

Thanks.

[ShadyMalatawey]

Change the policy at which the hosts connecting to the storage (Multipathing policy)

Right click on the datastore on that storage-> properties -> Manage Paths
U have three options: 1- Round Robin: which will randomize connections to each one of the 8 paths (one a time and hence u'll see the 8 are active)
2-) Fixed: which will make the paths to the datastore fixed till one is down, it'll be replaced.
3-) Last recently used: From its name, it'll use last one used to connect to the datastore.

Check this link for further explanation:

VMware KB: Multipathing policies in ESXi 5.x and ESXi/ESX 4.x

VMware KB: Modifying path information for ESXi/ESX hosts

Hope it really helps..

[ShadyMalatawey]

Anther thing..according to ur configuration, imho, it's good to have redundancy as much as possible as long as the HBAs and the SPs are there
What u did, it'll give u redundancy when u select Round Robin, will give u failover (Active-Passive with Failback) when using Fixed or failover (Active- passwive without Failback) using Most Recently Used.

[snowmizer]

Yeah I already had Round Robin selected on every path. I figured that the redundancy would be a good thing. I guess what I'd really like to do is be able to switch which paths show "Active (I/O)" while leaving the remaining paths "Active". Even though we aren't having performance problems on our VNX I'd like to try to distribute traffic to the 2 remaining ports on the VNX so that traffic is going down all 4. Unfortunately it looks like I can only enable or disable the paths not control which ones have IO on them.

Thanks.

[ShadyMalatawey]

If u select it Round Robin, all of the pathes will be active and connections will be rounded between them..

it shows only (Active I/O) in case of Most recently used or fixed..
Wish it helps

[snowmizer]

So it's deceiving. In reality traffic is going to all 8 ports.....sweet. I suppose the best way to verify that is to pull statistics from the VNX since I don't know of any way to verify the traffic on all 8 paths from VMware.

[ShadyMalatawey]

In Round Robin: First session to Storage is goind through first path seen by the system, the second session to the second path, etc...

So it's some sort os sessions distribution through all of ur pathes to ur storage
Hope it helps and plz dnt forget point if u wanna