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Tape Backups: First Line of Defense
If you’re like most businesses, you’re using some form of data protection today—probably tape-based backup. Periodically, someone shuts applications down to perform a backup to tape. Depending on the volume of data that is being copied, this may take several hours and requires manual intervention to set up the backup job, run it, confirm that it occurred, and then return the application to operation.
The backup copy may be kept locally in case data needs to be recovered in the near term, and eventually it may be moved to an off-site location for archival storage purposes. The reason to make and keep copies of your data is so that, in the event of some sort of event or catastrophe that deletes or destroys data, you have a clean copy safely tucked away to use for recovery purposes.
The two most important metrics for determining the optimal capabilities of any data protection strategy are the recovery point objective (RPO) and recovery time objective (RTO).
Recovery Time Objective (RTO). RTO defines how quickly you need to restore data and applications and have them fully functional again. The faster your RTO requirement, the closer you move to zero interruption in uptime and the highest level of data protection.
Recovery Point Objective (RPO). RPO defines the point at which the business absolutely cannot afford to lose data. It points to a place in each data stream where information must be available to put the data back in operation. Again, the closer you come to zero data loss and real-time access, the more continuous protection of data will be required.
Tape is used for backup and archive because it is very inexpensive, but it is an old technology that has been available almost since the dawn of computing. There are several issues with tape-based backup:
- Tape-based backup is a time-intensive process that is potentially disruptive to your applications; this issue is commonly referred to as the backup window problem.
- Because of its impact on applications and resources, tape-based backups are usually not performed more than once a day, and often only once every several days, meaning that there are very few tape-based recovery points available for use over the course of a week.
- Because your data is changing very frequently (on the order of seconds or minutes), fewer recovery points mean you are risking the loss of large amounts of current data for a given recovery.
- Once it is clear that a recovery needs to occur, it takes time to perform recovery tasks including locating the correct tape, transporting it (if it’s off-site), restoring it to disk and restarting the application with the recovered data.
- As storage media for backup data, tape is not entirely reliable; in fact, leading analyst groups such as the Gartner Group, the Enterprise Strategy Group and the Taneja Group state that as many as 1 in 4 backup tapes suffer from some sort of problem that precludes performing a recovery.
Transporting tapes to offsite facilities for archival purposes also has inherent risks. Recently publicized tape losses during physical transport (by truck) have hit large companies like Bank of America, Citigroup Inc., ChoicePoint Inc. and LexisNexis in the U.S. and resulted in the loss of hundreds of thousands of company records.
Replication of data across secure IP-based networks is a much faster, easier and safer way to transport data to off-site locations for archival storage purposes. If you are driven by either business or regulatory requirements to deploy a disaster recovery solution, a pure tape-based strategy can subject you to undue risk.
As all of these issues illustrate, tape-only backups are no longer a feasible data protection strategy in business environments that require frequent access and updates to critical business data.
Pinpoint the Most Valuable Data for Your Business
It has been proven over time that most data recovery requests are for relatively recent data, and that there is a direct correlation between the age of data and the possibility that it would be required for restore purposes. Most restore requests are driven by issues such as an inadvertently deleted file or data corruption that is introduced by a virus or a hacker.
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