We’ve had two customers impacted by this problem, so please take notice prior to upgrading or installing Vsphere 4.1 with Flex-10. Read links below for more specifics.
http://communities.vmware.com/message/1589996
Keep in mind this is written by a Cisco employee but it’s a good explanation of some of the differences between Cisco UCS networking and HP Blades Virtual Connect technology.
http://bradhedlund.com/2010/08/16/cisco-ucs-qos-vs-hp-virtual-connect-rate-limiting/
Great article pointing out the VMware networking differences between Flex-10 and UCS QoS. Of course HP is getting ready to make some more changes to their Flex-10 (Flex Fabric I think it is called) so stay tuned.
http://blog.aarondelp.com/2010/03/cisco-ucs-qos-vs-hp-flex-10-vnics-in.html