UltraBac will utilize an autoloader tape drive in sequential mode of operation by simply adding it to the "Use Devices in this Order:" list box. Multiple tape cartridges in the loader will be sequentially used automatically as they fill up during a backup. Restoring files from an autoloader in sequential mode is reasonably fast; each tape takes less than one minute to process until the required restore tape is located.
The BEI Medium Changer driver offers random access mode of operation – an optional cost module.
To install the new device driver, run Windows NT Setup and click on "Options". Use "Add/Remove Tape Devices" and click on the "Add" option and scroll through the list box and highlight and click on "Other". Key in the path name (e.g. C:\UltraBac\DRIVERS) and click on OK. Highlight and click on "BEI Medium Changer Driver" and click on OK. This will initiate the installation of the driver "MedChg". After installation is complete, restart Windows NT to activate the new autoloader driver, which will automatically start as a "System" device. As a note, when using the "Tools" option to view tape information, it will indicate the BEI medium changer (as opposed to medium changer) after installing BEI's driver.
After installing the BEI medium changer driver, the "Autoloader" option field becomes activated. Any value entered into this field before installing the BEI driver is ignored. The autoloader option is for entering the tape address number for a scheduled backup or a "Run Now" operation.
Each time UltraBac is run, the default tape is always cassette number one unless a tape is already loaded into the drive or a starting slot number is specified by a scheduled backup. When running an interactive backup via the "Backup" menu bar option, the default tape will always be cassette number one from the magazine unless there is already a tape loaded into the drive. Interactive backups always rewind a tape leaving it in the drive. Unattended backups have the option to either rewind the tape or eject it after the backup completes.
Random Access Backups
To start a backup to a specific tape in an autoloader magazine, access the Autoloader Options screen using the option path ("Scheduler"/"Scheduled Backups"/(highlight a group)/"Options"/"Autoloader Options").
Figure 57: Autoloader Options
Select "Start with Current Media" if the backup should start with the media currently loaded into the drive.
Selecting "If wrong media, start with slot 1" will cause the backup to begin with slot 1 if the wrong media is in the specified starting slot.
UltraBac will start the backup at the "Starting Autoloader Slot". Leaving this field blank will always start the backup from the first tape in the magazine. If the backup exceeds the capacity of the tape in the designated slot, the backup will automatically continue using the next sequential tape in the magazine. LIMITATIONS: A backup cannot span multiple magazines. Slot number validation is not performed and an unattended backup directed to an invalid slot number will fail with an error entry written to the application event log.
If the "Ending Autoloader Slot" number is reached, UltraBac will prompt the user to insert the next storage media. UltraBac will continue to prompt the user for every media change until the end of the current backup.
Backups, each accessing a separate tape device within an autoloader library, may simultaneously request tape changes. Only 1 instance of UltraBac can control the robotics at any one time. The other instances will simply wait for the loader to become available. The maximum wait is 10 minutes.
Random Access Restores
Random access restores are automatically performed when the BEI medium changer driver is installed. Both the online disk and tape-based indexes contain the autoloader slot number of each file in the backup to enable fast restores. Restoring from an online disk index would be the preferable method when available. If an online index does not exist to retrieve a file from a tape located in an autoloader magazine, the software would have to read each backup tape in the magazine to first locate the indexes.