Database Backups 101: Tips on How to Verify Your Backups

Database Backups 101: Tips on How to Verify Your Backups

Sarojini Devi Nagappan
05 March 2020

Everyone knows backups are an important part of recovery to minimize downtime but, having multiple backups with errors will not be of any use for any immediate recovery. 

Backup verification is a process to test the backup for errors or information loss which ideally should be a part of the backup and recovery policy. Having a verified backup gives a better assurance that the data in the backup is valid, readable, and free of errors. 

Many organisations invest in time, space, and cost to take and manage backups but, often neglect testing them. The reason for this is it takes time and requires extra space to restore and verify the completed backup.

Ensuring Timely Backup Verification 

It’s good to have a plan to completely restore the backup to the server and run a quick validity test periodically. Alternatively, if time and space are a constraint then you can opt to do a selective restore on certain files or tables. This, of course, is not comprehensive and would not be able to validate the accuracy of the backup. 

Always Simulate the Recovery Process

Testing a backup means you need to test the entire recovery process to minimize the operational downtime. This includes testing the backup devices on a system or over the network. 

Next, include the people who will be part of the recovery process, get them to pick the backup randomly and then restore some part of the data. This simulation will allow the people in charge to run the recovery process, check the backup validity, and finally check and amend any recovery process documentation.

Restoring Select Files 

A backup can be verified quickly using some of the files from the full backup. A quick way to check for the backup data validity is to restore selected files on an alternative location and check its contents against the original version. This would give a quick snapshot of the data validity. Of course, this is a test with selected files, therefore this does not guarantee the backup was done properly at the beginning or data validity of the entire backup. 

Next is to restore the files from the backup onto a different environment. This test gives the assurance that if the system is down, the backup files can still be accessed in a different environment.

Backup Verification Tools  

You can use backup utility tools or third party backup verification tools to manage the backup verification as it can be a time-consuming task. Different tools, however, can have different verification methods. 

Common verification done by the tools includes content verification, storage media check, read and write error check, and some even do the archive integrity testing. A good backup verification tool should include the following check the points: 

  • Size check: The backup verification tool can be configured to check the size of the file transferred to the backup. A range of size is entered and the file size is checked against this range.
  • File size deviation check: The tool can identify the files which do not meet the file size range and alert the administrator for further action.
  • File integrity check: The backup verification tool should be able to check the integrity of the backup at the destination to ensure the backups are not damaged during the transfer. File integrity should be checked frequently and if there is any violation, the tool should alert the administrator immediately.
  • Archive verification: The tool should be able to check for any file corruption before and during the backup process. It should also prevent the backup from any future file corruption to ensure the backup is always valid for the recovery.

Conclusion

Backups are like insurance during recovery. A valid backup reduces downtime and saves costs during a disaster period. It is essential to have a healthy backup of the configuration files for a quick recovery. 

Without a healthy backup, an organisation would need to invest in people and time to reconfigure the entire environment also this poses a situation to create new errors to restore the backups. This is one important reason to have a valid backup of configuration files. 

It is important to have an error-free data backup, which will help the organisation to restore all important files and folders in place during the recovery phase. Therefore, the key is to have a healthy backup, and backup verification is the best way to always test and validate the backups in the organisation, it may be time-consuming and expensive, but it sure does gives an assurance of being safe during the crisis.