Verification during Backup

When performing offline backups using the JADE Database utility (jdbutil), you can select or deselect the Verify Files and Verify Checksums check boxes on the Backup Database dialog, and your selections are retained across work sessions. The Verify Files option, when true (that is, checked), enables index block‑to‑target (object, subobject, and so on) verification, ensuring that index entries resolve to the correct records in the file. The Verify Checksums option, when true (that is, checked) means that file‑level MD5 checksum verification is to be performed on each file after being copied.

The backup commands provided by the offline batch JADE Database utility (jdbutilb) and the online JADE Database Administration utility (jdbadmin) support the verify argument, which enables file‑level checksum verification. Similarly, the verifyFiles parameter in the JadeDatabaseAdmin class backup methods enables file‑level checksum verification.

By default, offline backups and online quiesced backups perform index block‑to‑target (object, subobject, and so on) verification. An online updating (non-quiesced) backup does not perform the same checks, as it cannot do so when files are being updated. As part of your recovery strategy, non‑quiesced (that is, online updating) backups should be recovered to a temporary location where separate utility certification is performed to verify the backup contents.

Offline backup and online quiesced backup verification can be strengthened by setting the BackupOrphanCheckDisabled parameter in the [PersistentDb] section of the JADE initialization file to false. This causes target‑to‑index verification to occur.

Conversely, to make the verification weaker, set the value of the BackupIndexCrosscheckDisabled parameter in the [PersistentDb] section of the JADE initialization file to true, to disable the index‑to‑target verification. Where it is desirable to have an efficient backup process that fits comfortably in the processing window, you can set this parameter to true and then perform the JADE Database utility certify action after the backup, to certify the database using a temporary relocated (and checksum‑verified) copy of the backup. Offline backup processing overheads are lower when no cross‑checks are enabled, as data is not read into disk cache for use in verification.