VerifyData™ Silent Data Corruption Detection

Data errors can go unnoticed, undetected by the host operating system or disk firmware; these errors are known as silent data corruption. With the advent of larger drives and very fast RAID setups, Silent Data Corruption is becoming of increasing concern in the industry.Bacula Enterprise Edition’s VerifyDataTM  directly addresses this issue. In a wider sense, it can be used to increase operational security of your IT environment using its advanced and integrated Intrusion Detection technologies. VerifyDataTM  even provides ways to verify the reliability of existing backed up data.

  • Most backup solutions will claim to be able, in some way, to verify that the data on the backup volumes is actually usable
  • However, Bacula’s VerifyData has additional functionality; working as a file integrity scanner, finding files that have changed unexpectedly
  • Using VerifyData, Bacula Enterprise Edition indicates data security issues


VerifyData is able to efficiently and effectively check data and provide a report on data status.
These checks are able to address two different areas:

Verify Volume Metadata Integrity

Bacula Enterprise Edition has a powerful feature that compares metadata read from the media against that stored in the catalog. Reading the complete stored data can be expensive in terms of network bandwidth, CPU cycles, and storage I/O used. Bacula effectively addresses this issue by using a more effective approach than other solution providers. This is a well balanced approach to ensuring consistency and readability of the backed up data without having to actually read each stored object and processing it on the source system.


Regularly running test restores and comparing the files against their originals is a procedure recommended by Bacula Systems to ensure proper operation of your backup environment. VerifyData should only be used in addition to this approach, not to replace it.

Verify File System Integrity

Different kinds of File System Integrity checks are performed by Bacula VerifyData. In one example, Bacula implements a verification of the actual file system contents against what was last backed up as a ‘DiskToCatalog’ verification. Just the metadata is compared that is stored in the Bacula Catalog; this  keeps the verifications fast and efficient, as the backed up data does not need to be read from the storage media. Using checksums, file contents changes are likely to be detected. In a second approach, Bacula also keeps track of those files by collecting their metadata in its catalog without actually saving the files, and later compares the system’s files against the cataloged information.

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