VXA Autoloader Technology                                                                                                         August, 2004 Page 3 of 8                                                                                              The Manual Backup Process Considering the number of times that human intervention is required in a single tape drive backup process, it is not surprising that backup reliability is negatively impacted.  Figure 1 illustrates that a backup operator handles tapes 20 times in ten individual sessions over a two-week period.  The number increases if a restore operation is required, with a greater potential for error considering that the restore operator is likely different than the employee tasked with inserting the nightly backup tape. Each time human intervention is required, one of the following may occur: 1)    The proper tape is inserted, and the ejected tape is correctly filed. 2)    The proper tape is inserted, and the ejected tape is miss- filed, which will impact future backup or restore operations. 3)    The wrong tape is inserted, preventing the current day’s backup from occurring.  In the worst case, the backup software is configured to write over existing data on the tape. 4)    The employee is absent or neglects to change the tape, preventing the current day’s backup from occurring. 5)    The tape drive detects a mechanical anomaly while mounting the newly inserted tape, and ejects.  A stand-alone tape drive unit cannot reinsert and retry the tape without operator intervention. The backup process is generally reliable in its first month or two.   Habits are formed, and a few restores are performed to verify the process.  However, as weeks turn into months, the task of swapping tapes loses its aura of importance, particularly after a few months pass without the need to restore data.  Once the backup process begins to erode, months or years may pass before a problem is revealed, and often at the worst possible moment.   Labor costs of the manual backup process seem deceptively minimal yet accumulate significantly over time.  In the best case, adding a tape interchange task to an employee’s workload results in a disruption of at least fifteen minutes a day, the equivalent of over one work week per year.   Any media or tape loading error requires additional hours per event to recover, often requiring attendance outside normal business hours. Finally, the manual backup process becomes impractical once the volume of data exceeds the capacity of a single tape.  As such, a backup operator is required to mount subsequent tapes within an already tight event window hours after backup initiation.   At this point, backup operations suffer from either neglect or sporadic performance, or the investment in the inadequate backup tape drive is abandoned for a new, larger device. Figure 1 – Illustration of 20 tape movements over a two-week backup cycle. p1   p2   p3   p4   p5   p6   p7   p8