Data Backup Verification

A Backup Article Contributed by Ashley Lister

Data Backup Verification

One of the most vital things that needs to be done with any backup is data verification. It's not enough to simply backup data. To make sure the information you have copied is suitable for a potential restore it must be verified. There is little point in going through the lengthy and costly process of performing a data backup only to find that, when it is eventually needed, the data backup is not useable.

Data Backup Verification is a Relatively Simple Procedure. after a Data Backup Has Been Made, Verification is Run to Check That the Information That Has Been Backed up Matches the Information That is Still on the Machine. This Usually Involves the Computer "Counting" the Binary Information Contained at the Most Basic Level of Each File. in Verification, the Computer Will Count Two Sets of Figures: One from the Original Information and One from the Backup Information. Verification is Considered to Be Confirmed If These Two Totals are an Exact Match.

There are many reasons why verification could fail. Damaged or corrupt storage media could cause enough of a problem for the verification procedure to return an erroneous figure. Similarly, an error in verification could indicate that there is a problem with damaged, corrupt or bad sectors on the hard drive.

None of These are Particularly Pleasant Scenarios but, If Data Verification is Run Alongside Each Backup, This Process Itself Could Help to Indicate the First Stages of a Hard Drive Problem. Because These Problems Can Quickly Grow from a Minor Nuisance to a Major Disaster, It is Worth Considering There Value As a Potential Tool for Diagnosing a Problem before It Proves Injurious to Valuable Information.

There are Two Types of Data Backup Verification: Full System Verification and Sampling Verification.

As the names imply, full system verification checks everything that has been backed up and then compares it against everything that was specified in the original information. Sampling verification tests a small range of data information from the backup and, although this is not as comprehensive a test as the full system verification, it is not such a time consuming a process. Sampling verification does falls short of supplying a complete picture and this style of verification is not available with every data backup software solution.

The types of verification available will always depend on the data backup software you use. Not all backup softwares offer both types of verification and there are some that don't offer any opportunity for verification.

In the cases of those softwares that don't offer any option for backup verification the only way that data integrity can be measured is through the use of a system restore. However, unless a user has a spare machine available, onto which they can make a "test" restore, this is likely to be too great an infringement on resources.

More sensible,for those who do want the facility to verify data integrity, is to consider changing backup utilities to a software that provides this option.