UCS Virtual Interface Card Limitation

[warquezho0612]

What is the maximum virtual interface card in the Cisco UCS? I read that this depends on the number of uplinks between the IOM and FI and number of interface in use on other adapters sharing the same uplinks? But how?

[simon.geary]

There are two types of vNIC used with the VIC; Static and Dynamic. A Static vNIC (or vHBA) is a device that is visible to the OS or hypervisor. Dynamic vNICs are used for VM-FEX whereby a VM is connected to a veth port on the Fabric Interconnect.

As there are only a limited number of veth ports on each physical Fabric Interconnect port (128 shared between all blades), the number of Dynamic vNICs available depends on how many uplinks you have, and therefore how many physical Fabric Interconnect ports there are available.

The numbers are:

1 uplink = 13

2 uplinks = 28

4 uplinks = 58

Note that the number of Dynamic vNICs available will decrease for each Static vNIC or vHBA you create. So if you have four uplinks but your service profile has six Static vNICs you will have 52 Dynamic vNICs available.

[warquezho0612]

- Is the 4 uplinks pertains to both I/O module (2 on each I/O) or 4 uplinks to to a single I/O module only?

The numbers are:

1 uplink = 13

2 uplinks = 28

4 uplinks = 58

- Also does the numbers above only applies to Dynamic vNic? If yes then how many are available on a Static vNic?

- Any cisco documents regarding this?

[simon.geary]

The numbers are per FEX module. Both Static vNICs and Dynamic VNICs will consume one of these numbers. The number of Static vNICs you can create will depend on how many PCIe devices the underlying OS or hypervisor can handle. The config limits document gives a summary.

http://www.cisco.com/en/US/docs/unified_computing/ucs/sw/configuration_limits/limits_14/b_UCS_6100_Configuration_Limits_14.html

I noticed that in this doc it gives the maximum Dynamic vNICs as 56 and not 58 but this is because it assumes you will have two Static vNICs for uplinks, which makes sense I suppose.

[warquezho0612]

So just to clarify

1FEX or I/O Module gives me the following

1 uplink = 13

2 uplinks = 28

4 uplinks = 58

2FEX or I/O Module gives me the following

1 uplink = 26

2 uplinks = 56

4 uplinks = 116

Is the numbers above  correct?

Also when you said "The number of Static vNICs you can create will depend on how many PCIe devices the underlying OS or hypervisor can handle". Does it always depends on the OS or hypervisor? How about on the UCS side? How many can UCS handle?

[cweinhold]

The 128 veth's per physical port limit affects the 6120/6140.

How many veths are supported on the new 6248 in static pinning mode and in port-channel mode? Sean McGee's ciscolive preso indicated hosts can now have 126 vnics with the 6248, which suggests that the limit may be 1024 veths.

[Kirupairajah Satheeskumar]

Gents,

It depend on the Model of the Card and Number of FEX uplinks to FI.

http://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/c-series_integration/ucsm2-1/b_UCSM2-1_C-Integration/b_UCSM2-1_C-Integration_chapter_01.html#reference_7F381038303B4825ACD303765905086A