Information
If Virtual disk shrinking is done repeatedly it will cause the virtual disk to become unavailable resulting in a denial of service. You can prevent virtual disk shrinking by disabling it.
Rationale:
Shrinking a virtual disk reclaims unused space in it. If there is empty space in the disk, this process reduces the amount of space the virtual disk occupies on the host drive. Normal users and processes-that is, users and processes without root or administrator privileges-within virtual machines have the capability to invoke this procedure. However, if this is done repeatedly, the virtual disk can become unavailable while this shrinking is being performed, effectively causing a denial of service. In most datacenter environments, disk shrinking is not done, so you should disable this feature. Repeated disk shrinking can make a virtual disk unavailable. This capability is available to nonadministrative users in the guest.
Impact:
Inability to shrink virtual machine disks in the event that a datastore runs out of space.
Solution
To implement the recommended configuration state, run the following PowerCLI command:
# Add the setting to all VMs
Get-VM | New-AdvancedSetting -Name 'isolation.tools.diskShrink.disable' -value $true
Default Value:
The prescribed state is not the default state.