Troubleshooting Validation Issues
Categories: Error Codes, Troubleshooting, Backup Jobs, ADS, Alike v4
This article applies to the following errors:
Validation of VM [your VM name] completed due an issue with your network or storage. Please check logs.
BACKUP OF VM [your VM name] CONTAINS CORRUPT OR INVALID DATA! Please check media integrity and re-run backup!
Consolidation of blocks failed with getBlock failed for block 78307bd855803d5a190007bbafcd59c4 with error [x]
Alike validates backups after jobs complete. It does so by checking a list of digital signatures representing data blocks of backup disks against the digital signature of those blocks at the time of validation.
Alike always checks new blocks acquired during the backup to make sure they were stored correctly. It also periodically rechecks older blocks at an interval you can configure under Settings->Backup Settings->”Backup Validation.”
Alike needs to access your Alike Data Store (ADS) location in order to validate your backups. This means Alike will be generating I/O to this storage location (either local storage or network storage) during the validation process.
Because Alike tries to complete this process as quickly as possible, Alike will read and block off the ADS and recalculates the digital signatures, so you will notice a spike in I/O activity. If this process is consuming more I/O resources than you would prefer, you can dial back the re-validate time or disable validation completely.
If Alike is unable to read blocks due to a networking or storage intermittency, you will receive the following error in the Alike UI dashboard and alerts:
- Validation of VM [your VM name] completed due an issue with your network or storage. Please check logs.
The next step in this case is to look at your BackupSCheduler log, located under Tools->Alike Logs, and find errors that occurred during this time. You are likely to find log messages such as:
- Consolidation of blocks failed with getBlock failed for block 78307bd855803d5a190007bbafcd59c4 with error [x]
The error message in the brackets will be a Windows error code and Windows error message indicating the root cause. Typical issues are network disconnections from the CIFS location or Windows OS resource problems. The Windows Event log may have additional information in the case of SAN/iscsi issues connectivity issues.
If you receive this message in the Alike dashboard or alerts section:
- BACKUP OF VM [your VM name] CONTAINS CORRUPT OR INVALID DATA! Please check media integrity and re-run backup!
This likely indicates that one or more blocks associated with your backup have digital signatures that do not match. This can happen if an delayed I/O problem occurred writing the blocks to this ADS during the commit phase of the job.
It can also happen if the contents of the disk change underneath Alike due to either storage problems, virus, or accident. In this case, it is prudent to run hardware and filesystem checks appropriate to your storage configuration to determine the root cause of the issue.
If are still receiving these error codes after troubleshooting, please open a support ticket. See the KB article, “How to Use Quadric Support,” for instructions on how to open a ticket.