Network Load Balancing (WLBS) and virtual machines
We where having trouble configuring a new network load balancing (WLBS) cluster. We have several host machines that each run a guest where all guests should be part of one cluster.
We started by preparing the first guest:
- Created diskimages
- Installed the os
- Installed software
- Updated all software
- Shutdown
We now have a virtual machine and then
- Copied it to all host machines
- Started all guest
- Add all guest to a domain
This is where weird behavior started to occur as some guest could not communicate and worst of all we could not create a network load balancing cluster with the network load balancing manager.
Turns out that all guests shared the same SID and NIC id's. We forgot to
- Run SysInternal's NewSid tool on each guest to reset the SID
- Remove the virtual NIC's and re-adding them to reset the NIC id's.
A bit of information can be found at the following knowledge base article:
Network Load Balancing Manager does not work with imaged servers
No interfaces are available for installing a new cluster
http://support.microsoft.com/kb/828258
So what is the lesson learned? That after copying a virtual machine to remove all NIC's at first startup, rebooting AND then running NewSid BEFORE adding the guest to a domain. I knew about the SID issues as I experienced similar behavior in the old days when you created Ghost images and restored them on several machines but what is new for me is the NIC stuff.