What is a disk safe?

Data on the backup server is stored in Disk Safe storage format. This on-disk format enables the backup server to archive point-in-time recovery images for long periods of time using as little disk space as possible. The backup server then periodically connects to the backup Agent program (buagent) on the server/host being backed up and synchronizes changed disk sectors to the backup server.The point-in-time backup images are called Recovery Points and are stored in a Disk Safe.

More information on DiskSafes:

You cannot backup a Host/server until it has at least one DiskSafe.

New backups can only be stored in the most recent DiskSafe.

You can restore from any available Incremental backup image in any DiskSafe.