max vnics on C460-M2, managed by UCS

[Walter Dey]

Is there a max limit on the number of vnics, that a C460-M2, managed by UCSM supports ?

UCS V2.1.2a, C460-M2 connected to FI, 2 x VIC-1225, SP defined with 8 vnics.

On association, customer sees error message

failed

connection-placement

there are not enough resources overall

not enough vnics available

[Walter Dey]

I found the answer, see Table 2 and 3 in

http://www.cisco.com/en/US/docs/unified_computing/ucs/c-series_integration/ucsm2.1/b_UCSM2-1_C-Integration.pdf

[Keny Perez]

wdey,

You are right again, the same logic applies to B series where the max amount of vnics depends also on the amount of links between the IOMs and the Fabric Interconnects; that is where you begin to think about how many links you need from the IOM to the FI and what should be the CDP (Chassis Discovery Policy) you use.

CDP will determine the minimum amount of links (per FEX) needed to discover the chassis, but it is important to understand that if you set CDP to 1-link, the system will initially just discover/use that one link; even if you have 4/8 cables plugged in, and to make all links usable, a chassis reack is needed, just keep that in mind always.

-Kenny

[Walter Dey]

Important caveat, if you use a port-channel between IOM (only 22xx) and FI (only 62xx)

In port-channel mode, when you cable between FEX and the FI, the available virtual interface (VIF) namespace

varies, depending on where the uplinks are connected to the FI ports:

•

When port-channel uplinks from the FEX are connected only within a set of eight ports managed by a

single chip, Cisco UCS Manager maximizes the number of VIFs used in service profiles deployed on

the servers.

•

If uplink connections are distributed across ports managed by separate chips, the VIF count is decreased.

For example (see Figure), if you connect seven members of the port channel to ports 1

member to port 9, this port channel can only support VIFs as though it had one member.

– 7, but the eighth