Unable to power on virtual machines on ESXi host with the error: "Invalid or unsupported virtual machine configuration."

Problem

You’ve noticed that the Recent Tasks in your vCenter’s task list is displaying the following error when attempting to perform a Power On virtual machine task:

Invalid or unsupported virtual machine configuration.

Reviewing the detail of the task displays the following Task Details:

Name: Power On virtual machine

Status: Invalid or unsupported virtual machine configuration.

Error Stack:

An error was received from the ESX host while powering on VM <vmName>.

Transport (VMDB) error -45: Failed to connect to peer process.

Failed to power on’/vmfs/volumes/<GUID>/<vmName>/<vmName>.vmx’.

The problem appears to be host specific because you are able to power on the virtual machine if you move it to a different host.

Establishing an SSH session to the host and reviewing the logs show the following message constantly logged:

Cannot create file /tmp/.SwapInfoSysSwap.lock.LOCK for process hostd-worker because the inode table of its ramdisk (tmp) is full.

Solution

The environment where I encountered this issue was running HP ProLiant BL660c Gen8 blades which the VMware support engineer told me apparently had a bug that constantly wrote logs to the /tmp/vmware-root folder that eventually filled up the partition. To verify this, navigate to the /tmp/vmware-root folder and use the ls command to list the contents:

Note the amount of vmware-vmx-xxxxxxx.log files in the directory in the screenshot above. To correct the issue, either move the files out of the directory to an external storage device or simply delete them. In this example, I will use the rm vmware-vmx-xxx* command to delete the files. The reason why I am required to narrow down the file to a 3 digit + wildcard is because there are simply too many files in the directory to use vmware-vmx-* (if you try using that, you will get a Argument list too long message).

The problem should go away once the files are removed.