Virtual Connect links between enclosures

chuckk281 — Wed, 18 Jul 2012 14:57:52 GMT

A question from Barry:

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Is it possible to link 2 enclosures, that are each in a separate VC domain? So that traffic that is on the same vlan ID (and vc network name) goes through that link and not an uplink to a core switch??

The customer doesn’t want to go down the multi-enclosure VC domain.

I’ve got 2 connected together now, but I’m not seeing any indication that they are seeing each other. I’m only using 1Gb SFP. The customer is going to 10Gb once they settle on a switch…. Usual story.

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Input from Dan:

You can do a “back to back” connection between 2 Enclosures (or really any 2 domains if you have MES in one/both of them) but there are 2 things to consider.

1) You have to turn the Failover Mode from Auto to Manual and then make sure both sides have the same link as Primary. An auto failover will only occur if the link is disconnected or the VC module on either side fails causing the other side to go Link Down.

2) Whatever Networks/VLANs/SUSs you associate with this back2back connection will ONLY exist within both VC Domains and CANNOT leave either enclosure through a normal SUS uplink to a Core Switch. This is because we do not allow traffic to come in through an uplink (what the back2back is considered) and then leave another uplink. And any 1 Network/VLAN can only be associated with 1 uplink.

So for a RAC Cluster, MSCS Cluster or vMotion network that will only exist between the 2 enclosures, this is probably ok. But you will not be able to ping anything on that network from outside.

Just imagine you took 2 DL380s and ran a crossover cable between the 2 machines, as that’s effectively what you are building.

And some input from Anton:

Think this scenario is described here(connecting VC modules in different domains) : p. 26/27 in http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c01732252/c01732252.pdf

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Other comments or suggestions?

topic Virtual Connect links between enclosures in BladeSystem - General

Virtual Connect links between enclosures