is Virtual Connect stacking required?

[Dave Arkfeld]

This is a new install for Internal use. I have just 2 adjacent VC FlexFabric 10GB/24-port modules, how do I enable the internal stacking option? I need to use ports x1 and X2 for San, and port X5,X6,X7,X8 for 1GB ethernet. I am getting this indication:

Connection Status: Failed

Redundancy Status: No Redundancy

[JKytsi]

X7 and X8 are shared ports. If You use them to connect network, You will lose the internal x-links.

So remove networks and connections from those ports.

[The Brit]

is there a reason you are not using ports X3 and X4.     If you used X3, X4, X5, and X6 for your 1G Ethernet uplinks, you would not need to use X7 and X8.

The explanation of your error messages (my interpretation):    X0 provides a default horizontal stacking link between Bay 1 and Bay 2, however this is a single path and provides no redundance.     I think VC considers redundancy to be 'necessary' and therefore reports the stacking links as "Failed".

I would agree with the earlier poster that removing connections and references to X7 and X8 will probably get rid of your "Failed" indicators.

Note however, X0 is a hard connection which probably doesn't need redundancy, and if it showed up as truly "Failed" then you probably have bigger backplane issues.

[Dave Arkfeld]

I am not using X3 and X4 because  x1 - x4 only support 10gb ethernet only.

[The Brit]

OK. Wasn't aware of that, (I do not use FlexFabric, only Flex10 and older).

[Dave Arkfeld]

How can I check if x0 is the issue. In the documentation I found this reference "The ISL ports provide stacking links between adjacent modules." So is x7 and x8 considered the "ISL ports" and I can't used those for my 1GB Ethernet connectivity?

[The Brit]

I have never used this option, however there is a VC CLI command, "show stackinglink". Based on the documentation, it is supposed to: "Display a summary listing of all stacking links and status"

[Bob_Vance]

It appears to me that the X0 port is not a port, per se, but is essentially represents the horizontal backplane physical connection. My conjecture is that it is not used for anything unless at least one of X7 or X8 is unpopulated in each horizontal pair, in which case, it "makes the connection" between the X7 (X8) ports. So, it's more like a cable.
Note that the reference to X0 has been removed from the VC 4.20 Setup and Installation Guide 2014-04-18.

So, the X0 "port" is not bad; VC just wants a horizontal stack link.

I would bet (a Diet Coke) that if you were to remove the 2 X7 SFPs, the "FAILED" would go away, but "No Redundasncy" would stay.

The work-around for the stack-link error when X7 & X8 are both in use is to use one or both of X3,X4 for horizontal stacking links via a 10G DAC.

See:
http://hpblogs.lithium.com/t5/Eye-on-Blades-Blog-Trends-in/Can-you-use-the-Virtual-Connect-stacking-links-as-pure-uplinks/ba-p/99055#.U77HUpRdXp0

Note that this page also addresses some points relevant to my original question (the topic of this thread).
Apparently, BOTH the OA and the stacking links can be used for VC management, with the stack link being default.
So, the answer is that the stack link is not *required* in my scenario, but it is not *suppported* by HP.

bv