how to browse a backup file?

the .vma file inside of a .vma.lzo or .vma.gz archive. I want to inspect the contained files.
 
i see. if I extract it there is a .raw file that I can´t handle either. So the only way to look on the files is to restore the backup?
 
I have to add a question related to this topic: the reason I wanted to know the initial question is because I have a VM with a mounted ecryptfs-folder and I wanted to know if a backup with mode "Snapshot" contains any data that could help an attacker in possession of a Snapshot-file to decrypt the files.