maxRetentionDays

This is the setting that specifies the maximum retention period that the vault retains its recovery points. If this parameter is not specified, Backup does not enforce a maximum retention period on the recovery points in the vault (allowing indefinite storage).

If specified, any backup or copy job to the vault must have a lifecycle policy with a retention period equal to or shorter than the maximum retention period. If the job retention period is longer than that maximum retention period, then the vault fails the backup or copy job, and you should either modify your lifecycle settings or use a different vault.