VM snapshots are one of the best virtualization features ever. But…have you ever had a VMware vSphere or Hyper-V snapshot grow out of control and fill the datastore the VM resides on? You know what happens… The VM crashes and goes into a suspended state until free space is added to the datastore. Even the best VM admins out there seem to get burned once when they create a snapshot for some routine maintenance and just forget about it afterwards.
Sometimes this task is harder than it sounds. If your SAN is out of space, or the SAN management tools are out of your control, you could be stuck.
We just added a how-to guide to show you how to create a failsafe placeholder in each datastore that you can delete to buy yourself some time in the event that a rogue snapshot or other operation is about to fill up a VM’s datastore.