The Grandfather-Father-Son Tape Rotation
The Grandfather-Father-Son scheme tape rotation is an industry-standard. It's appropriate for most small businesses.
The benefit is a compromise of protection, convenience and performance.
NUMBER OF TAPES REQUIRED
You have first to decide on the desired 'restore window'.
A typical business with a five-day work week will use a 20-tape rotation that will give them a one-year restore window.
Many, if not most businesses will also keep yearly tapes which can come in handy for tax reporting purposes.
For a five-day work week you will need a total of 20 tapes but if you back up 6 days a week you will need 22.
This will allow you to restore files as recent as yesterday and as old as one year.
A six-month restore window requires 14 tapes.
TAPE LABELS
Daily Tapes (Also called "Son tapes")
Four tapes will be used every Monday through Thursday. These tapes will be used every week and will see the most wear and tear. It is recommended the daily tapes be shifted to the monthly group once in a while so they don't wear out prematurely...like rotating the tires on your car.
- Monday (Day 1)
- Tuesday (Day 2)
- Wednesday (Day 3)
- Thursday (Day 4)
Weekly Tapes (Also called "Father tapes")
Four more of your tapes will be used once a month on Fridays. (or Saturdays, depending on whether or not you are backing up a six-day workweek). Whenever it appears you need a Friday Week 5 tape, you can probably just use the EOM tape.
- Friday Week 1
- Friday Week 2
- Friday Week 3
- Friday Week 4
Monthly Tapes (Also called "Grandfather tapes")
Twelve of your tapes will be used on the last business day of each month.
- January EOM
- February EOM
- March EOM
- April EOM
- May EOM
- June EOM
- July EOM
- August EOM
- September EOM
- October EOM
- November EOM
- December EOM
OFF-SITE STORAGE
You’ve been diligent in your backup practices, performing a perfect tape rotation and keeping your tapes readily available on a shelf in your server room. What’s wrong with this picture?
OK, your data is protected against a server failure. At most, it will take a few hours to recover your server.
Are you aware that your data is not protected against natural disaster. What if a fire broke out in your server room from a wiring fault?
Your precious backup tapes just got melted down along with the server, and all data is lost.
In this case, a wise investment for the server room is a heavy duty fireproof safe for storing tapes. That way, if you have a fire, your tapes should be able to survive. But what if you have flooding? Even if you don’t live in a flood plain, stranger things have happened than one of the restrooms on the floor above you having a busted pipe that causes water to rain down through the ceiling tiles. Fireproof safes aren’t waterproof, and while your server shorts out and crashes your tapes are going under water.
What if your building is hit by a tornado?
The only way to really ensure that your data is protected is to store copies offsite. In the GFS tape rotation the monthly backups, or Grandfathers, are taken offsite for storage.
If you have a natural disaster that strikes the office building and server room and wipes out you data, you have the ace in the hole so to speak and can probably recover enough of the company data to at least be able to carry on with business.
In addition to protecting against natural disaster, storing tapes offsite also protects against the possibility of losing all corporate data to theft or vandalism.
Offsite tape vaulting is an option that any company should not but MUST consider.
RELIABILITY
Please note that any backup system absolutely depends on daily attention and periodic maintenance.
Every backup system requires a "backup administrator" to change the tapes every day, to store them in the proper location and to monitor the backup logs for any errors.
Periodically, every backup system needs to be tested in order to be sure data is actually being backed up and can be restored when needed. Tape drives also need to be periodically cleaned. With most tape drives, this generally means occasionally inserting a cleaning tape.
CLEANING TAPES
Cleaning Tapes should be kept on hand at all times! Use the cleaning tape every month before inserting your Monthly EOM tape, or whenever the 'status' light flashes on the front of the tape drive. Whichever comes first!
Cleaning tapes don't last forever! Get a new one every year or according to the instructions on the cleaning tape itself or at least don't use a cleaning tape more than 20 times.
Examples of Schedule
5-day Backup Schedule
Ex: Month of November 2011| Monday | Tuesday | Wednesday | Thursday | Friday | Saturday | Sunday |
|---|---|---|---|---|---|---|
| 1 Backup : Diff Tape : Day 1 | 2 Backup : Diff Tape : Day 2 | 3 Backup : Diff Tape : Day 3 | 4 Backup : Full Tape : Week 1 | 5 None | 6 None | |
| 7 Backup : Diff Tape : Day 1 | 8 Backup : Diff Tape : Day 2 | 9 Backup : Diff Tape : Day 3 | 10 Backup : Diff Tape : Day 4 | 11 Backup : Full Tape : Week 2 | 12 None | 13 None |
| 14 Backup : Diff Tape : Day 1 | 15 Backup : Diff Tape : Day 2 | 16 Backup : Diff Tape : Day 3 | 17 Backup : Diff Tape : Day 4 | 18 Backup : Full Tape : Week 3 | 19 None | 20 None |
| 21 Backup : Diff Tape : Day 1 | 22 Backup : Diff Tape : Day 2 | 23 Backup : Diff Tape : Day 3 | 24 Backup : Diff Tape : Day 4 | 25 Backup : Full Tape : November EOM | 26 None | 27 None |
| 28 Backup : Diff Tape : Day 1 | 29 Backup : Diff Tape : Day 2 | 30 Backup : Diff Tape : Day 3 |
7-day Backup Schedule
Ex: Month of November 2011| Monday | Tuesday | Wednesday | Thursday | Friday | Saturday | Sunday |
|---|---|---|---|---|---|---|
| 1 Backup : Diff Tape : Day 1 | 2 Backup : Diff Tape : Day 2 | 3 Backup : Diff Tape : Day 3 | 4 Backup : Diff Tape : Day 4 | 5 Backup : Diff Tape : Day 5 | 6 Backup : Diff Tape : Day 6 | |
| 7 Backup : Full Tape : Week 1 | 8 Backup : Diff Tape : Day 1 | 9 Backup : Diff Tape : Day 2 | 10 Backup : Diff Tape : Day 3 | 11 Backup : Diff Tape : Day 4 | 12 Backup : Diff Tape : Day 5 | 13 Backup : Diff Tape : Day 6 |
| 14 Backup : Full Tape : Week 1 | 15 Backup : Diff Tape : Day 1 | 16 Backup : Diff Tape : Day 2 | 17 Backup : Diff Tape : Day 3 | 18 Backup : Diff Tape : Day 4 | 19 Backup : Diff Tape : Day 5 | 20 Backup : Diff Tape : Day 6 |
| 21 Backup : Full Tape : Week 1 | 22 Backup : Diff Tape : Day 1 | 23 Backup : Diff Tape : Day 2 | 24 Backup : Diff Tape : Day 3 | 25 Backup : Diff Tape : Day 4 | 26 Backup : Diff Tape : Day 5 | 27 Backup : Diff Tape : Day 6 |
| 28 Backup : Full Tape : Week 1 | 29 Backup : Diff Tape : Day 1 | 30 Backup : Diff Tape : Day 2 |
