Hi,
The Nexus 1000V document on scalability-limits provides information in this regard. Here is the link below:
http://www.cisco.com/en/US/docs/switches/datacenter/nexus1000/sw/4_0/release/notes/N1000V_RN.html#wp56977
A bit more information in addition to the document link:
1) Data Center is a vCenter concept, and under a Data Center multiple vDS (distributed virtual switch) could be created.
Nexus 1000V VSM instance maps directly to a vDS instance, and a user can create multiple N1K vDS switches as
well under a data center in the vCenter.
2) on a vCenter, multiple Data Centers could be created. However, I beleive VMware does put a limit of 16 vDS per vCenter
and across Data-Centers.
3) One instance of VSM in the current release supports upto 2K Virtual Interfaces, which maps to the Virtual Machine
interfaces (VNICs), and also to the VM kernel nics (e.g. vmknic0, vswif0, ..). So the scalability limit is wrt the number
VNIC ports, and not with the VM count. For e.g. if a VM uses 2 VNICs on average, ~1K VMs could be enabled.
I hope this help answer your queries. Please let us know if any additional information needed.
Regards,
Munish.