Is it safe to use Timeshift in Whonix?
Why not use VM snapshots?
You can use SubVersioN which is recommended over snapshots for VM backups.
SubVersioN (SVN) Backup Tool
SubVersioN is considered the best alternative tool for backing up VM operating environments. It is similar to VirtualBox’s snapshot feature, but is much more reliable and efficient. Prior to using it, familiarize yourself with the tool’s documentation and design. SVN clients are available for various platforms.
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