Web app performs slowly on IE6 and IE8 on XP against virtualised web server

[jbrazil]

Virtualising a critical web (ASP.NET) app Client PC - physical PC runs XP with IE6 or IE8 Web server - guest VM runs W2K3 R2 with IIS7 ESXi host - Dell E710 runs ESXi 4.1.0 - 2 x Intel 83576 NICs (set to 100 MB Full to match switch speed)

Symptoms

A critical web app function responds v. slowly using XP and IE for the client. Function is AJAX-based. PerfMon shows Send rate from local NIC (various NICs tested) runs v. low when waiting for response then Receive rate spikes when response comes. Using a physical web server backend, this never happens. Equivalent perfmon shows Send spike and immediate Receive spike. Local NIC is throttling back Send speed just for that web function. Can max out Send with a file copy for e.g.

Windows 7 client + IE9 - no issue

Firefox 5 on XP - no issue

Physical web server - no issue

Would like an explanation/fix if possible

[jamesbowling]

We need more information regarding the VM.  How many vCPU, was it a P2V, does it use VMXNET3?  Any information you can provide about the VM will help with possibly seeing if this is VMware related or not.

[jbrazil]

Hi,

Yes the VM was P2V'ed. It has 4 x vCPUs (customer wanted to replicate physical server). 4GB RAM. 2 x vdisks. Storage is local filesystem i.e.no SAN. NIC Driver is E1000 not vmxnet3.

Any other info required?

Thanks,

Padraig.

[jamesbowling]

My first question would be was it performing normal prior to the P2V?

[jbrazil]

Yes it was fine prior to P2V - as noted in the original post, all works fine against equivalent physical web server.

Thanks,

Padraig