Virtual Machines on same ESXi 5 host: what kind of throughput should I expect

I had this same issue, but only for our replicated LUNs in the cluster. We were migrating from 4.0u1 to 4.1u1. The solution was simply to log into each host and run the command:

# esxcfg-volume -l  to view the datastores
# esxcfg-volume -m "vmfs_label_name"

Then go back to the VI client and refresh Storage - the datastore should be in the inventory.

I'm similarly not entirely comfortable with the solution, kinda weird, but thought I'd share.

There are reasons that you'd want to spread your uplinks from a vSwitch out between multiple physical switches -- but mostly for redundancy purposes, not for decreasing the length of the path that the traffic will need to take for communication between a client and a virtual machine.

How exactly this behaves depends on the configuration of your vSwitch -- in the NIC teaming tab, the settings that dictate how the NICs will be used are the Load Balancing drop-down, as well as the active/standby state of the adapters.

The Port ID and MAC hash configurations will both effectively assign each VM's traffic to a specific physical NIC - so traffic outbound from that VM (and inbound to the VM, due to the switches' MAC address table) will be stuck to the same physical NIC until something changes (like the NIC topology changing due to one going down, for instance).

The other load balancing option is IP hash, but you don't want that when uplinking to multiple switches; you'll get all kinds of MAC address flapping.

In general, layer 2 switching is not capable of taking the shortest physical path to something; there's just one working path, at least until TRILL starts taking off.

You can potentially manually control which switch a specific VM tends to be pointed at; would that be helpful?