A Win2k3 SP2 server running MS SQL Server 2k SP4 was converting at about 25Gb/Hr. The system drive is local, and the other drives are on an MSA1000 connected by fiber channel. What might be causing this slow performance? Will old NIC drivers cause slow speeds, or should I be looking elsewhere?
There could be many factors. The speed of your drives,networking or even backups on the network could cause long migration times. Are you doing Volume based or Disk based cloning? Do some trace routes from your target to the source and make sure it not doing something funky. I've had some migrations myself take 15 hours or more. It just depends on the environment and how much data you are trying to copy.
What speed are your nics connecting at?
It turns out that there was not a battery cache on the controller of the ESX box in question. A battery cache was used from another server, and the tranfer rate almost quadrupled. Before doing this, the ESX box had no buffer to write the converted VM.