I've recently loaded ESX4 Update2 on two whitebox servers that I'm using for data backup and DR purposes. Both have 64-bit Quad-Core Intel E5405 CPUs, plenty of RAM, supported SATA controllers, and on-board supported Intel NICs.
I did a P2V migration for the OS that originally was the base OS (Windows Server 2008 SP1) on Server A, and it is now a VM on that server. It was also running on Server B. That OS is running a network monitoring tool (PRTG) that I use to keep an eye on my network, including latency within my network, and to my remote sites.
What I've noticed is that, when the Windows VM is running on both Server A and Server B, I see surprisingly variable ping latency to both the service console on both servers, as well as from the VM out to the various hosts on the network. I thought initially that it was a WAN issue, until I realized that the latency was being experienced from the VM even within the LAN, and even from the VM to the IP address of the service console for its host ESX hypervisor.
Other pings between hosts on the LAN show <1ms latency with little variability, so the issue seems isolated to the ESX environment.
What could be causing this, and what can I do about it? I don't see evidence of poor networking performance either in the service console environment or the VM environment -- file transfers are speedy enough, both when moving the VM between servers last night and copying files via Windows networking.
PRTG supports having remote probes, so I could move the probe portion of my network monitoring to another non-VMWare server, but I'd like to understand this issue before I resort to that. I've seen some discussion related to network latency in older versions of VMWare, but nothing with 3.5 of 4.0.
