The CA documentation mentions using the vbr utility to remove old backups:
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CA Performance Management - 3.5
file is required to remove a backup or restore from an older series of backups.
7. (Optional) Remove older backup sequences as required with the vbr utility with the remove task using the configuration that was used to create it.
/opt/vertica/bin/vbr.py --task remove --archive=[<date>_<time>|"all"] --config- file configuration_directory_path_filename
The remove command is destructive and removes the data and free space on the disk. The archive must be specified to remove a single restore point, a comma separated list, or "all". To display the list of backups, run --task listbackup.
Is this really necessary if you want to remove an entire set of snapshots? Or can you just delete them using the O/S without any issues being created for the vertica DB?
There is data stored in the database itself regarding snapshots using the vbr utilities will keep this data consistent/up to date.The listbackup task is actually reading this information from the Vertica database.