In addition to BRU Server’s Auto Balancing™ of the drive selection being automated, BRU Server also handles tape media differently than most backup applications to provide the longest possible life for your media. With most backup applications, when a backup operation is set to overwrite a series of tapes, the backup will automatically reset the first tape for use to the first slot in the assigned tape pool. This can result in some tapes in a pool being used excessively while others may never be used.
BRU Server’s tape use algorithm is designed to ensure that tapes within a defined destination are used equally. Therefore, overwrite jobs will always start with the least used tape in a destination. For example, if you have a destination with 8 defined slots and the first backup used tapes 1-4, when you next run an overwrite job to that destination, the backup will start on the tape in slot 5 rather than restart with the tape in slot 1.
This means that when handling the media for removal and rotation, you should always remove ALL tapes assigned to a destination, not just the ones that you think were written to in the last backup operation.
When a job is set to append, please be aware that the append operation only applies to the first tape used if the appended archive uses more than one tape. If you are using a standalone tape device, please be certain that the additional tapes provided can be safely overwritten as no checks will be made to prevent their full use. When using a library, the append method will always start the append from the last used tape in a destination, so the following tapes will not be part of the previous backups sent to that destination. However, to be safe, please be sure that any rotation methods remove and replace ALL tapes in a destination as outlined above.
Additionally, if you have tapes that you wish to protect from future overwriting, you can mark the tape as “Unwritable” in the Tapes panel of the Data Manager tab. Refer to chapter 6 - “Data Manager” for specific information.