Which of the following is NOT a valid backup command for a Security Management Server?

'save backup' is not a valid Gaia OS CLI command - the correct syntax for creating a system backup is 'add backup', not 'save backup'. Check Point Gaia uses the 'add' verb for creating backups and snapshots, so 'save backup' would return a command not found error in the Gaia CLI.

'add backup' is a valid Gaia CLI command that creates a compressed backup of the system configuration and can be stored locally or on a remote server.

'add snapshot' is a valid Gaia CLI command that creates a full system snapshot capturing the entire OS state and can be used for system restore.

'migrate export' is a valid Check Point command used to export the Security Management Server database for migration or backup purposes.