By Rick Cook
A full backup every evening is expensive, time consuming and often unnecessary. However the schedule of backups depends in large part on how busy the server is that's been scheduled for backup.
At its website, Hewlett Packard suggest three schedules for single-server backup in a small business or workgroup environment: Using 3, 6 or 10 tapes. (Assuming a complete backup fits on a single tape, as it should.)
The three-tape system works best when there is very little change in the data on the server in the course of any given week. It involves doing a total backup on the first Monday night, and modified backups the rest of the week using the second tape each time. On the following Monday, make a full backup to the third tape and take the first tape off-site. The second tape is erased and re-used for daily-modified backups.
The six-tape schedule assumes a moderate amount of change in the data and perhaps heavier data volumes than the three-tape system. The six-tape system involves doing a total backup on the first Monday, partial backups on separate tapes during the week (assuming the business only operates Monday through Friday) and another total backup on Friday evening. The total backup tape goes offsite immediately and the process is repeated the following week.
The ten-tape schedule is the six-tape schedule with some modifications. Like the six-tape schedule, a full backup is performed on Monday, modified backups are done through the week and a total backup is done for off-site storage at the end of the week. The difference between the six- and ten-tape schedule is that the full backups from previous weeks are also kept and retained for a month's worth of data when you use all ten tapes.
More information on backup schedules and other matters related to tape backup for single servers and small businesses can be found at Hewlett Packard's Web site devoted to its Colorado line of small tape drives, at http://www.hp.com/tape/colorado/basics.html
About the author: Rick Cook has been writing about mass storage since the days when the term meant an 80K floppy disk. The computers he learned on used ferrite cores and magnetic drums. For the last twenty years he has been a freelance writer specializing in storage and other computer issues.