Recently we deployed some Windows Server 2008 R2 RDS virtual servers to a customer. All was working well until a number of users were deployed to the servers. The servers would freeze for the users on the server when another user logged in. It would freeze at the preparing local session manager stage
After opening a support call with Microsoft we were instructed to rebuild the server on a physical server. On a physical box the problem went away.
Eventually it was found that adding another CPU to the VM resolved the issue. Vmware were also able to recreate the issue and an official bug has been logged for their product.
Its usual practice to RDP to a Virtualcenter box and then access the Console of Virtual Machines. However today I had a customer where when they went to the console screen of the VMs it just was black. No image was drawn at all.
Restarting the Virtualcenter server and the ESX servers did not resolve the matter.
The solution in the end was to increase the colour depth of the RDP session. With 256 Colours the Console screen is not drawn. Never knew that.
I had an error message come up about a VM:
The redolog of xxxxx.xx.vmdk has been detected to be corrupt. The virtual machine needs to be powered on. If the problem still persists, you need to discard the redolog.
I couldn’t power off the VM and it was stuck in an endless loop prompting me to click okay.
Found a good guide on how to kill the VM without having to power cycle the host.
Read more…
If you have been unfortunate enough to find yourself with loads of snapshots in ESX and have snapshots with file sizes bigger than a couple of GB. Then you might be scared to commit them in case of data loss.
You can easily get rid of all the snapshots without any data loss. Using the VMKFS tools you can clone out the hard drives in their current state including snapshots to 1 VMDK. To do this run the following when SSH’d in.
vmkfstools -i harddrivename-000001.vmdk /vmfs/volumes/datastore/ new foldername/new_harddrivename.vmdk
Then it will clone the drive. This may take a couple of hours depending on the size of your drive. Then you just attach the new drive to a newly created VM.
VMware Knowledgebase : 1002458
Found out a nifty command which allows you to find out what VM’s have Delta / Snapshot files. Run this when SSH’d in.
find /vmfs/volumes/ -name "*delta*" -type f -print0 | xargs -0 du --human-readable --total