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Backup tips
The most important thing that you can do to insure the long term success of your computer installation is to maintain a regimen of normal, periodic backups. Accurate backup is just as important as accurate data entry.
Tape backup is currently my preferred medium. It is fast, reliable, able to handle large volumes and transportable.
| Medium | R e l i a b l e |
F a s t |
C a p a c i t y |
R e m o v a b l e |
T r a n s p o r t a b l e |
H a r d w a r e $ |
M e d i a $ |
R e c o m m e n d e d |
Comment |
|---|---|---|---|---|---|---|---|---|---|
| USB drive | 3 | 2 | 2 | Yes | Yes | 1 | 1 | Yes | The best overall solution. These highly reliable, high capacity drives are the recommended backup medium for consumers and small businesses. |
| Removable hard drive | 3 | 3 | 3 | Yes | Yes | 2 | 3 | Yes | The fastest, reliable and most expensive form of backup. |
| Tape | 3 | 3 | 3 | Yes | No | 3 | 2 | Yes | Store entire contents of a system on a single tape. Multiple tape styles and formats. |
| Internet | 3 | 1 | 3 | Yes | Yes | 1 | 2 | Yes | Backup your critical files on the internet. Viability of provider must be taken into consideration. |
| DVD-ROM | 2 | 2 | 3 | Yes | Yes | 2 | 1 | Maybe | Excellent for images. Larger capacity and more reliable than CD-ROM |
| CD-ROM | 2 | 2 | 2 | Yes | Yes | 1 | 1 | No | Excellent for images Not recommended for databases. |
| X drive | 3 | 3 | 3 | No | No | 1 | 1 | No | Backup your information on another disk drive on the same computer. Only should be use to backup temporary files. |
| Network Drive | 3 | 3 | 3 | No | No | 1 | 1 | No | Backup your information to another computer in your network. Only when your primary backup device in down. |
| Dead & Dying Technology | |||||||||
| Floppy | 1 | 1 | 1 | Yes | Yes | 1 | 1 | No | Media is not always readable between computers. Very limited capacity. |
| Zip Disk | 2 | 2 | 2 | Yes | No | 2 | 2 | No | Medium tends to be unreliable. |
Why do I need to backup?
You need to backup the information on your computer system because things go wrong. Having adequate backup will insure that the lost or corrupt information can be replaced immediately.
Losing your entire computer system (through hardware failure, fire, theft, lightening strike, etc.) is actually not the worst thing that can happen. When those events occur, you simply replace the lost or damaged equipment and reload from backup! It usually only takes a few hours to fully restore a system.
Programs such as spreadsheets and word processors seem to corrupt files continuously. (I write all of my accounting programs using Microsoft Word 6.0 for Unix. This obsolete program allows me to write up to 200 lines of programs per hour, but the hidden cost is an average 3-5 corrupt program files per week!)
An operator can inadvertently delete or rename files.
The index to a database file can become corrupt and perform incorrect updates, often destroying an entire database days before the program itself actually crashes.
Backup a much information as you are willing to lose.
Backup frequency varies by installation. A company with 20 operators on two shifts must backup every day. A one person office probably needs to backup once a week or less.
Rotate your backup tapes.
The biggest mistake regarding backup that I see is failure to rotate your backup tapes. (See backup rotation schedule). It is not unusual to discover a corrupt file days or weeks after it became unusable. Yesterdays' backup will not solve the problem. You need last Thursdays' or maybe even a backup from October.
The best backup rotation schedule.
This backup technique requires 10 tapes and will insure that a data file can be recovered even if it was corrupted up to 3 months ago. Create the following labels and attach them to the backup tape:
Monday
Tuesday
Wednesday
Thursday
Friday 1-7: January, April, July, October
Friday 1-7: February, May, August, November
Friday 1-7: March, June, September, December
Friday 8-14
Friday 15-21
Friday 22-31
Leave the Monday through Thursday tapes at the office. Take all of the Friday tapes home. Use the tape that matches the day to be backed up.
Additional safety measure.
Make a full system backup at fiscal year and store the tape as long as you store your written accounting records.
Put label on the tape.
The date label should be attached to the tape itself, not the tape box. This will eliminate the problem of mixing up tapes that are out of their respective boxes.
Keep your backup tapes off site.
If your office is hit by fire, flood or theft, there is an excellent chance that you will not only lose your computer system, but all of your backup tapes. Your computer is insured. Your backup tapes are insured. The data on the tapes is not insured. Keep your weekly/monthly/annual tape backups at home. Only bring in the tape that is needed that day.
Backup your entire file system.
A backup tape should contain every piece of information that your computers' hard drive contains. If any component of your system becomes lost or corrupt, it can easily be reloaded.
Verify your backup.
Most backup routines offer a verify option that compares the information on the tape to the information on the disk. This will detect disk drive, tape drive and tape media errors before they become catastrophic.
Clean your tape drive on a regular basis.
Tape drive manufacturers recommend cleaning on a weekly basis. A clean drive will result in less data read / write errors.
Use automatic backup processes whenever possible.
Most operating systems include an automatic backup option. Their use will allow unattended backups to occur during the late night/early morning hours when the chance for operator activity is less likely.
Read your mail.
Most automatic backup routines will mail the results to you. Read the mail. Did the backup complete successfully? Where there any read or verify errors?
What makes me an expert.
I have been selling, installing and supporting multiple user accounting systems since 1978, 3 years before the IBM PC was released! I have had to deal with hundreds of cases of lost or missing files, file corruption, system crashes and outright hardware failures. Clients that follow my advise HAVE NEVER lost ANY information.