Verify Checksums

Run this utility to perform a checksum analysis of your backed up database files, or your restored system to verify that the files have not been corrupted by a hardware or environmental problem during the backup or restoration process. This utility is specifically related to the backup process.

A verify checksum operation must always be run before a database is restored from backup, or when backup files are moved from one location (or media) to another. When a restore operation is processed using the jdbutil.exe form, a verify checksum operation is incorporated into the process.

Use the jdbutil.exe form to run the verify checksum utility. Select the Verify Checksums option from the Operation menu. You are prompted to enter the directory path of the database you are checking.

The checksums verification operation is driven from the backupinfo file in the directory specified here. This file is created in the Greentree Desktop directory when the original backup is taken (from the Task Scheduler or jdbutil.exe form).

Note: When an online backup is taken using the Task Scheduler, the option to verify checksums is selected. Leave this option selected so that the backup process completes a verify checksum operation when the files have been backed up.

When the utility is activated, each file whose checksum is verified displays in the running report to the form. During the process, Greentree Desktop is comparing each database file with data in the backupinfo file, to check that integrity is in tact. You can abort the run anytime by clicking the Cancel button.

If the operation completes successfully, the progress dialog displays this message:

If the operation does not complete successfully, a message to indicate errors will display, for example:

Errors were found in 2 file(s)

<<Checksum verification complete>>

Checksum error(s) exist

Refer to checksum.log

If errors are found following a verify checksum operation, one or more of the database files is not in the same state as it was when the backup was taken. This does not necessarily mean that the database files are corrupted or that the backup is useless. A verification occurs if there have been any changes to the database. This could include actions such as logging in to the backed up database, performing a compact on backed up files, and the like.

If the verification process fails:

Consider whether any changes have been made to backed up files that would change their state since the backup. If changes have been made, there probably are no problems with the backed up database and the failed verification is the result of those changes.
If you are sure that no changes have been made to backed up files, then a failed verification indicates that the files have become corrupted in some way by a hardware or environmental problem during the backup or restoration process. Always include the verification checksum operation in your test plan, especially if backed up data is being transferred across different media.