f a VM file has three snapshots, deleting all will cause the changes from the third delta file to be copied to the second file. Data from the second delta file will be copied to the first and from the first to the original VM. The delta files are deleted only after the commit process is complete.
If each delta file size is 50 GB, an additional 150 GB storage space would be required to accommodate the growing size of delta files. The commit process for a 100 GB snapshot typically takes three to five hours. This process will therefore put an additional performance overhead on the original VMs and the virtual server infrastructure. A degraded system and application performance, especially in a production environment would be unacceptable.
Virtual Machine Snapshot Files
Virtual machine snapshot consists of multiple files. Virtual Machine snapshot mainly includes the following:
Settings state : Virtual machine’s settings (.nvram & .vmx) and power state
Disk State: state of the virtual machine’s associated disks
Memory state: Contents of virtual machine’s memory (Only if memory snapshot is selected)
Below are the some of the files which comprise of snapshot:
VM_name.vmsd
VM_name-snasphot#.vmsn
VM_name-00000#.vmdk
VM_name-00000#-delta.vmdk
VM_name-snapshot#.vmem
Below is the comparison of Virtual machine files in the virtual machine directory before and after creating the first snapshot of the virtual machine.
