VMware: Unable to migrate VM, missing snapshot file and out of space Error

The error in the headline is right out of snapshot hell. If you have virtual machines (VMs) with large memory requirements, you probably know that you need extra space on the datastore to store the Memory Swap file (.vswp).

When datastore housing the VM runs out of diskspace, you will not be able to create new VMs, power on existing VMs, and may notice performance issues with the VMs that are running.

Here is how to fix the error and successfully vMotion the VM:

Turning OFF or reducing the memory size on VM will reduce the amount of space required for memory swap file and that will free up disk space on the datastore (housing other VMs).

Using VMware converter to copy the VM to another host or datastore, the new VM will not have a snapshot.

For Future or NEW VMs, you also have an option to store the swap files with the VM or another datastore on non-replicated LUN. In vCenter, click on a HOST, go to CONFIGURATION tab and then “Swap file location” then click on EDIT for list of options.

In order to avoid dealing with .vswp file (allocating extra space for those files), you may make reservation for the virtual machine that is equal to amount of RAM assigned to it. For example, if you have a VM with 4GB RAM assigned, you can edit the VM settings > Resource tab to get to the reservation settings for memory, CPU of a VM.

I hope above helps you avoid future out of space or missing snapshot errors. If you have questions or comments or another virtualization support issue, please post in our discussion forums.