Unfortunately, as this strategy implies, the data that has been added or changed during the week remains unprotected. To enable data to be protected and restored between full backup cycles, companies have implemented incremental backup strategies. .
Incremental backups reflect the status of data at specified points in time, usually on a daily basis at times of no user activity. With incremental backups, only new or changed data is duplicated, thereby, more efficiently protecting the data throughout the week. It is recommended that a schedule be put into effect when dealing with both incremental and full backups. Most companies use the daily, weekly, monthly approach. The daily backups are, of course, run daily using a different tape for each day. All seven tapes should be kept no less than one week. At the end of each week, the weekly backups are recorded and all four tapes should be kept for at least one month. In accordance with the previous two backup practices, monthly backups should be performed on the last day of every month and all twelve tapes should be kept up to one year. According to company practices, the weekly and monthly backups can be either full or incremental. However, depending on the company size and the amount of data generated, it is recommended that both the weekly and monthly recordings be done fully.
As mentioned earlier, on-site and off-site backups play an important role in the survival of company data. A philosophy of backup management is to "hope for the best, but plan for the worst" (Nelson). That being said, it is always a good idea to have some type of on-site backup for speedy recovery of data in the case of a computer glitch or failure. However, if a fire or natural disaster destroys the office, all of the equipment and all of the computer files, more than likely, the on-site backup was also destroyed. Although the disaster probably could not have been prevented, the loss of the essential company data could have been.
