VMware Workstation Error: Cannot find a valid peer process

Question

I am running VMware Workstation 6.1.5 (build-126130) on CentOS 5.3 (Final).

One of the guest machines is reporting an error when I try to power on the most recent snapshot. Snapshots further back in the timeline will power on without any problem.

Error: Unable to change virtual machine power state: Cannot find a valid peer process to connect to.

Others have been reporting this problem since at least early 2005. The forums say to delete unused lock files and restart any hung VMware processes (or restart the host machine), which I have done.

Still no luck. Any other ideas?

Solution

I tried to clone the snapshot before making more changes, just to have a backup, and that failed too.

Cloning failed: reached the host's limit for open files.

Thinking the errors are related, I looked into how many files are actually part of this VM. The list was HUGE.

I have 13 snapshots before the one giving me trouble, so I tried deleting a few of them to reduce the number of files VMware would need to open. This fixed everything. I could have increased the max number of open files, but many of those snapshots were not needed any longer.