Be especially diligent with snapshot use on high-transaction virtual machines such as email and database servers.Take the snapshot, make the changes to the virtual machine, and delete/commit the snapshot as soon as you have verified the proper working state of the virtual machine.

This prevents snapshots from growing so large as to cause issues when deleting/committing them to the original virtual machine disks.

Use no single snapshot for more than 24-72 hours.

Here is the important bullet point from that KB: From VMware KB 1025279 The title of the KB is “Best practices for virtual machine snapshots in the VMware environment”. Personally, I think the real fix to this issue is to follow best practices. The example in the KB shows you how to change it from the default value of 15 minutes to 3 hours, probably an over kill but then you make sure the corner case of long snapshot consolidation timing out won’t happen again.

This example uses 10800 seconds, or 3 hours. Note: The value 10800 can be changed based on your requirements. To increase the timeout values for the virtual machine migration task, add the following timeout parameter in the vpxd.cfg file: In the same KB it talks about increasing the timeout, from the KB: It is updated every minute which means the delta files are being committed to the. Note: In the case of snapshot consolidation, even though the VI Client timeout occurs, the operation on the ESX host is still running. VCenter has a default 15 minute timeout for any task.

The task timing out from the vShpere Client is actually expected. When you run the command it will basically execute ‘ls’ with the above parameters every 2 seconds and any changes that occur with updated time or size differences will be highlighted. l shows a long listing which displays additional information regarding the files themselves. d highlights the differences between successive updates The above command is described in VMware KB 1007566, from that KB: vmfs/volumes/datastore1/VM-1 # watch -d 'ls -lut | grep -E 'delta|flat''

Snapshot consolidation