Validating a backup
The validation process verifies the restorability of online data. To avoid transmitting large amounts of data, DS-Client sends the encryption keys to DS-System where it performs the data validation. Although the keys are sent in encrypted format to the DS-System and immediately discarded once the validation is complete, you must accept, acknowledge, and agree to send the encryption keys.
NOTE: You must be a DS-Client administrator to schedule or perform validation.
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 the process 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 skips the file and reports the 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. The DS-System marks the corresponding backup 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 similar to a 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 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 on 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 backups, since there is no data on the DS-System to validate.
To validate a backup:
1. Click the Backup Sets tab.
2. Select the backup you want to validate.
3. On the Restore menu, click Validation.
4. Do the following:
a) In the Private Key box, type the private key for the DS-Client.
b) In the Account Key box, type the account key for the DS-Client.
c) Under Selections, select the type of validation you want to perform. The options are as follows:
• All online data – Validates all generations of files in the backup.
• Selective – Allows you to specify the files to validate.
d) Click Next:.
5. Select the directories you want to validate, and then click Finish.