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C Class enclosure interconnect slots

S Petersen
Advisor

C Class enclosure interconnect slots

Greetings,

I found that we have been given some Cisco 9124e switches so I thought I should give them a go. We already have SAN pass through modules in interconnect 3 and 4. I read some vague document that suggested that you could have a mixture of SAN Pass through modules, 9124e switches and Virtual Connect modules and they could all work..

So, I put the 9124e's into interconnect 7 and 8 in one enclosure with little in it and nothing untowards happened. I then found out that the particular enclosure has a network problem and I needed to move the 9124e's to another enclosure in interconnect 7 an 8. As soon as they went in, a 680C complained about a pot mismatch. So I moved them to interconnect 5 and 6 and another server complained about a mismatch.

Some of the system log says.

A port mismatch was found with server blade bay 8 and interconnect bay 6.
...

Blade in bay #8 status changed from OK to Degraded.
Mismatching I/O was detected on Blade 8, Mezz card 2, Port 3.

Once I withdrew the two 9124e's all seems to be ok again. The actual servers did not notice anything that I can see.

The dumb thing about this is that Mezz card 2 does not have anything in it. However, looking at the Graphical View, there is a tick in the Mezz slot 2. The ports that are not even there in my opinion say they are using the bays 5, 6, 7 and 8.

The other blade in another slot did the same thing. It complained about a mezz card that is not there.

What could be the problem? Is the solution just unticking a box in Port Mapping?

Regards

Stephen
12 REPLIES
JKytsi
Honored Contributor

Re: C Class enclosure interconnect slots

Do You know the c-class port mapping basics ?

What mezzazine cards You have in the server and in which slots ?
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S Petersen
Advisor

Re: C Class enclosure interconnect slots

---- Do You know the c-class port mapping basics ?

I expect that by that you mean that the onboard nic's go to interconnect bays 1 and 2.

Mezz card 1 goes t interconnect 3 and 4. That leaves mezz card 2 going to 5 and 6 adn 7 and 8.

---- What mezzazine cards You have in the server and in which slots ?

All our servers have mezz cards in slot 1. Generally for normal usage, we only have interconnect bays 1, 2, 3 and 4 in use.

I had a look at another of the blades in the enclosure that did not complain. In OA, it clearly states that Mezz slot 2 has no card present. The two blades that complained look different in OA. The Mezz Slot 2 "tick Box" is ticked and the grayed out ports are mapped to the right bays. What I did not realise is that two of the blades actually have cards there. Table view shows very clearly that Mezz slot 2 has some quad port 1 Gb NICs.

This changes my plans a lot. The servers that complained are Hyper V and obviously need these extra NICs.

Thanks for making me look in the right spot.

Stephen
Adrian Clint
Honored Contributor

Re: C Class enclosure interconnect slots

The 9124 SAN switches in a c7000 enclosure in interconnects 7&8 will only connect to full height blades if you have a HBA in mezz3 and a 2 port NIC in mezz2.

They will not connect to half height blades at all.
S Petersen
Advisor

Re: C Class enclosure interconnect slots


--- The 9124 SAN switches in a c7000 enclosure in interconnects 7&8 will only connect to full height blades if you have a HBA in mezz3 and a 2 port NIC in mezz2.

--- They will not connect to half height blades at all.

Going by the diagram for port mapping of the half-height servers, Mezz 2 gives an indication that it can connect to 7/8. The OA admin guide shows that a Mezz 2 that uses a PCIe x8 (interesting) slot can address interconnect 5 and 6 as well as 7 and 8? The full height blades are even more interesting.

My main error was that as there is nothing physically in the interconnect bays 5 and 6, I assumed they were not being used. Someone has put NC326m Dual Port 1 Gb NIC for c-Class Bladesystem cards in some of the servers. They use interconnect 5 and 6 (half height and 7 and 8 full height) even though there is nothing can be seen in the interconnect bays.

Anyway, I have learnt a valuable lesson on this and it changes our architecture design for SAN a lot. VC bandwidth for virtualisation systems just can't offer the bandwidth especially in a full C Class running hot little 490's. This was not so much about the 9124e, it was about using the interconnects.

JKytsi
Honored Contributor

Re: C Class enclosure interconnect slots

We have two enclosures full of 490 servers and we don't see any problems with VC.

You need to have quad-port mezz card to reach interconnect bays 7/8 from half-height machine
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You can find me from Twitter @JKytsi
The Brit
Honored Contributor

Re: C Class enclosure interconnect slots

As Jarkko (and the c7000 wiring diagram indicates),

The only way a halfheight blade can make use of IC Bays 7 and 8, is if there is a quad port NIC in MEZZ 2. In which case NIC port 3 maps to Bay 7 and NIC port 4 maps to Bay 8.

Dave.
S Petersen
Advisor

Re: C Class enclosure interconnect slots

Quad port mezz card?

Are you satisfied with the VC performance with so many systems using it? VC with only 4 x 4 Gpbs is not what I would think enough for heavy usage. I admit that its probably unlikely that all 16 servers would be pushing past 1 Gbps at the same time but I don't want that hassle if I can design something else.

VC looks great and if they could use 8 x 4 Gpbs FC ports (or even 4 x 8 Gpbs), it would sell me. However our network people would rather loose a limb than use VC. I don't know why and it gives me some impression its a loss of "individuality".

S Petersen
Advisor

Re: C Class enclosure interconnect slots

Hi Dave,

--- The only way a halfheight blade can make use of IC Bays 7 and 8, is if there is a quad port NIC in MEZZ 2. In which case NIC port 3 maps to Bay 7 and NIC port 4 maps to Bay 8

Are you saying that in that scenerio, the card in Mezz 1 would see the 9124e in interconnect 5 and 6?

I have a 460 and a 680 in this rack that first identified me of this problem. When I put the 9124e into interconnect 7 and 8, the 680 complained. It has a NC325m Quad port NIC in Mezz slot 2 and it uses interconnects 5,6,7 and 8.

I then put the 9124e into interconnect 5 and 6 and the 460 also complained. It has a NC326 Dual port NIC in Mezz slot 2 and it uses interconnect 5 and 6.

I guess the two systems made for an interesting day. I just don't have a 460 with a Quad port NIC in Mezz slot 2 to see what happens.

I really have to reread those manuals.

Thanks for our help.

Stephen
JKytsi
Honored Contributor

Re: C Class enclosure interconnect slots

well ...we have 8Gb VC FC modules (8Gb FC HBAs and 8Gb director core switches)but so far using only 1 uplink per module and not seeing any performance problems. But that of course depends of usage (we are running ESX vSphere)
Remember to give Kudos to answers! (click the KUDOS star)

You can find me from Twitter @JKytsi
S Petersen
Advisor

Re: C Class enclosure interconnect slots

I see that the 8 Gpbs has recently been released and it's about time. Thanks for your comments.
The Brit
Honored Contributor

Re: C Class enclosure interconnect slots

Hi Stephen,

If you look at the attachment you will see that

a) Mezz1 can only handle dual port cards, (NICs or HBA), and that the two ports map to Interconnect Bays 3 and 4. This mapping is hard and you have no control over that.

b) Mezz slot 2 can take either a dual or a quad card. in either case, then then ports 1 & 2 map to IC Bays 5 & 6. If it is a quad, the ports 3 and 4 map to IC Bays 7 & 8. These mappings are all hard, and beyond your control.

The port mismap that you mentioned in your original post usually happens because you have a Ethernet port on the blade mapped to a FC module on the Interconnect, (or viceversa).

Hope this helps

Dave.
S Petersen
Advisor

Re: C Class enclosure interconnect slots

Thanks Dave. I didn't know about the quad port cards and to tell the truth, I doubt our server operations people did either. I am just a poor SAN guy trying to sort stuff out.. :)

I am not really interested in VC with those 24 port 8 Gpbs cards.