Validating a backup set
The validation process verifies the restorability of online data. To avoid transmitting large amounts of data, DS-Client sends the encryption keys (private key and account key) to DS-System where it performs the data validation. Although the keys are sent in encrypted format to DS-System and immediately discarded once validation is complete, you must accept, acknowledge, and agree to send the encryption keys.
NOTE: You must be a DS-Client administrator to schedule validation or perform it on demand.
For each file generation, DS‑System:
1. Checks the file header, delta linking, and library linking.
2. Tries to validate the data by performing a virtual restore. The data is decrypted and decompressed to generate the original file signature. If it fails due to a decryption or decompression problem, the validation fails.
3. Compares the validation signature with the original one. If they do not match, the validation fails.
For validation failures:
• If a file originally did not have a signature that is needed for validation, a warning appears.
• If the validation fails due to networking issues, validation will skip the file and report the corresponding errors in both the DS-System and DS-Client event logs.
• If a file corruption is detected (including if the digital signatures do not match), the file and all files that depend on it are moved to the DS-System trash. DS-System marks the corresponding backup set as "out of sync" and a corresponding error appears in both the DS-System and DS-Client event logs.
The validation process is disk I/O intensive on the DS-System side because the digital signature of each file must be checked. The process is almost the same as an actual restore, except the data is deleted after comparing the signatures. It is recommended that you schedule the validation process at less resource-intensive times.
The scheduled validation also has the option to resume from the point of interruption of the previous scheduled validation process. To determine the interruption point, the files are processed in sequence based the share ID, directory ID, file ID and generation. On demand validations do not have the resume mechanism.
NOTE: Validation is not available for statistical backup sets, since there is no data on DS-System to validate.
To perform validation on demand:
1. Browse the Backup Sets tree and select the backup set you want to validate.
2. On the Restore menu, click Validation. The Validation Wizard appears.
3. On the Set validation settings page, type the DS-Client encryption keys.
4. In the Selections section, choose the type of validation you want to perform:
• All online data — This option validates all generations of all data in this backup set.
• Selective — This option allows you to specify the files to validate.
5. Click Next:.
6. In the Select directories/files to validate page, select the items you want.
NOTE: All items are selected if All online data was selected in the previous page.
7. Click Finish to start the validation.