Limitation of Snapshot
Snapshot can affect VM performance and do not support some disk type. Snapshots are useful as short term solutions for capturing point in time VM’s state’s and are not appropriate for long term VM backups.
1. VMware does not support snapshots of raw disks, RDM physical mode disks or OS that use an iSCSI initiate in the guest.
2. VM’s with independent disk must be powered off before you take a snapshot. Snapshots of powered ON or suspended VM’s with independent disk are not supported.
3. Snapshots are not supported with PCI vSphere direct path I/O devices.
4. VMware does not support snapshots of VM’s configured for bus sharing. The alternative solution is to consider running backup software in your guest OS. If your VM currently has snapshots that prevent you from configuring bus sharing, delete or consolidate the snapshots.
5. Snapshots supports or provide point in time image of a disk that backup solutions can use but snapshot is not meant to be a method of backup and recovery. If the files containing a VM are lost, its snapshot files are also lost. Large numbers of snapshots are difficult to manage, consume large amount of disk space and are not protected in case of hardware failure.
6. It can negatively affect the performance of a VM. Performance degradation is based on how long a snapshot or snapshot tree is in place, the depth of a tree and how much the virtual machine and it’s guest OS have changed from the time you took the snapshot. It might have a delay in the amount of time It takes the VM to power ON.
Note: Do not run production VM’s from snapshots on a permanent basis.