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To easily revert the VM to an earlier state
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To shut down the server
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As a backup tool for your VMs
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To create albums
EXPLANATION
Snapshots provide a fast and easy way to revert the virtual
machine to a previous state. For this reason, virtual machine snapshots
are intended mainly for use in development and test environments. Having
an easy way to revert a virtual machine can be very useful if you need
to recreate a specific state or condition so that you can troubleshoot a
problem.
There are certain circumstances in which it may make sense to use
snapshots in a production environment. For example, you can use
snapshots to provide a way to revert a potentially risky operation in a
production environment, such as applying an update to the software
running in the virtual machine.
Many backup products use snapshots in a production environment. They
create a snapshot and then processing continues from the snapshot,
meanwhile they have an unchanging original to back up. Once the backup
is completed the snapshot is merged back into the live environment. This
allows a machine to be backed up with very little affect for the users
and for them remains up 24/7.
NB: Hyper-V snapshots do not replace backups. Backup usually
involves some form of duplication (so two copies of the protected data
exist) but in snapshots... there is no duplication whatsoever. All data
is in VHD(X) file and changes in AVHD(X) file and if the VHD(X) file is
damaged/lost, the data is pretty much gone. Also with most backups you
can restore a single file to an earlier state, but with Snapshots, it's
all or nothing (meaning if an user wants a file from last week, you'd
have to bring the whole system back a week). There are other concerns as
well (there might be performance issues with multiple snapshots,
snapshots usually lose value as they age and there are issues with disk
space)
SOURCE
https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1015180