HPE EVA Storage

SAN rules re: Storage & HBA ports & Quads

 
Paul_637
Regular Advisor

SAN rules re: Storage & HBA ports & Quads

I've gone through the SAN Design guide and can't find any guidance specific to my scenario.

Given the following environment, what would be the best-practice way of cabling up a fabric?

HP c-Class Blade with 2 x 20-port VC-FC modules
2 x Storageworks 8/40 SAN switches (24 ports enabled)
2 x MSA2000fc (dual controllers - possibly expanding to 4 x MSA later)
4 x DL380s (dual port FC - possibly expanding to 8 x DLs later)

Specifically I'm looking to ensure I'm following sensible guidelines as to which devices get connected to which quads on the switches.

I've seen some references saying to avoid configuring hosts & targets on the same quad, and others (although specifically referring to EVA connections to be fair) saying to avoid EVA connections to the same quad.

So, should I try to spread out the load (across the 6 available quads) or perhaps designate storage quads & host quads?

Target O/S's are windows & VMware boxes, no other O/S planned.

Any suggestions appreciated.

Paul
5 REPLIES 5
Martin Smoral
Trusted Contributor

Re: SAN rules re: Storage & HBA ports & Quads

I would reccomend taking 2 adjacent uplink ports from the VC FC module in slot 3 and connect them to 2 adjacent ports in the same Quad port group on your SAN 8/40 Switch in order to create a Trunk. then repeat with VC FC slot 4 and the other SAN Switch. Then as you stated spread out the MSA connections on seperate Quads and plug the DL's in anywhere.
Paul_637
Regular Advisor

Re: SAN rules re: Storage & HBA ports & Quads

Ah, that's interesting. Is there such a thing as a "trunk" from a VC-FC module to a SAN switch?

As it happens I'm planning on connecting all for of each VC-FC module (20-port model) so that it's "set & forget" configured rather than someone having to come back later to change things but I've always been led to believe that each VC-FC uplink is independant of the others (and, in fact, serves distinct server bays in the enclosure).
Martin Smoral
Trusted Contributor

Re: SAN rules re: Storage & HBA ports & Quads

By default the uplinks ports from the VC-FC module to the SAN use Dymanic login Distribution, which is kinda like a trunk: Here is the details: Dynamic Login Distribution allows for login balancing and auto failover of the VC-FC uplink ports for host connectivity in the enclosure. Because there is no physical mapping of the host to the VC-FC uplink ports, the physical server blade placement in the enclosure does not need to be planned. Host login connections
to the VC-FC uplink ports are handled dynamically, and the load is balanced across all available ports in the group.
Paul_637
Regular Advisor

Re: SAN rules re: Storage & HBA ports & Quads

This thread gets more interesting as it goes along :)

Although it's been a while since I installed my last cClass, I do recall info at the time (with the original 4Gb VC-FC) relating to physical port-mappings. A quick google lead me to a site I remember finding very useful info at http://vinf.net/2008/04/09/how-does-an-hp-fibre-channel-virtual-connect-module-work/ (specifically the section titled "Which VC-FC Port does my blade's HBA map to?".

Has this config changed in the newer modules? ISTR seeing HP documentation somewhere supporting the above info but, again, that was some time ago now.

If it no longer works this way then that is indeed a step in the right direction!
Martin Smoral
Trusted Contributor

Re: SAN rules re: Storage & HBA ports & Quads

Paul,
this is from the latest version of the VC for Dummies book.

Fibre Channel (FC)login distribution and
failover features The Virtual Connect Fibre Channel connection provides login distribution and failover on FC uplinks to the SAN. A failure in your server connectivity with the SAN is a major problem. So HP has designed Virtual Connect Fibre Channel with built-in functionality that can automatically login to another active Fibre Channel port if a Fibre Channel connection fails. In other words, Virtual Connect provides Fibre Channel (FC)
login distribution and failover features, which means that the SAN administrator can automatically distribute server HBA
fabric logins across all Virtual Connect Fiber Channel (VC-FC) uplink ports on the same VC-FC module. Should a port fail or
lose the link, the VC-FC module bautomatically relogs the WWN into the fabric on another active VC-FC uplink port from the nsame VC-FC module.