Data Backup: Developing an Effective Data Retention Policy
(The first in a three part series. Jump to Part Two: What do you HAVE to back up?)
Archiving one’s data is a challenge for every business, whether the business is a billion dollar enterprise or a SOHO.
Data loss can be devastating to the profitability of any enterprise, and data recovery can be a nightmare if not planned for correctly. Developing and committing to an effective data retention policy is something that each business owner wrestles with, and correct implementation can mean life or death of a company in a disaster situation. Understanding how your data is retained is the foundation of any effective data retention policy.
Data retention is no new concept, but the method has certainly evolved. The early days of data retention policies were historically done in a classic “son – father – grandfather” routine where “son” is most current data backup, “father” is a previous older version of the data backup, “grandfather” is oldest version of the data backup in the rotation. In the old days, you might have had 5 daily backup tapes, each of which were considered the “sons.” Then you would save all your data every Friday for 4 to 5 weeks and those were the “father.” On the 5th Friday, you took the oldest Friday out of the rotation and saved that into the “grandfather” batch. And viola, that was the extent of your data retention policy. It was a gigantic storage capacity hog, and it was time intensive.
Sometimes the time required for each data backup was so many hours that starting a backup at the close of business did not always guarantee that it would be done by the start of the next day. This period is called the Backup Window. In order to try to shorten the Backup Window, a technique called Incremental Backup was introduced. An Incremental Backup only includes files that were changed since the last Full Backup. Incremental Backup adds a layer of complexity and attendant risk into the data backup process. (more…)