true image restore&synthetic backup

[samkumar]

what is True Image Restore and what is the use of it? what the relation between true image restore and synthetic backup

[revarooo · Accepted solution]

Google search would help you find a definition - this previous forum post has a good summary: https://www-secure.symantec.com/connect/forums/true-image-restores-whats-point

The TIR information is only taken at the start of either Differential or Cumulative backups.

The process involves taking a "snapshot" of which files are where in the volume being backed up. Using this information NetBackup can know which files have been removed (or moved) since the previous backup.

TIR information is used during the restores. If you perform a TIR restore, NetBackup will only restore files that were in the file system at the time of the last TIR backup. If a normal restore is done, all files are restored even if they were deleted between the time of the full and following incrementals.

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For Synthetic Backups, you must have TIR enabled.

See this technote

True image restore and synthesized backups

http://www.veritas.com/docs/000079451

[Nicolai]

Bare Metal Restore uses the TIR information as well.

As a addition to Revaroo fine post - you could say TIR is about tracking changed files - espcially files renamed or deleted - thus not modifying archive bit, where as synthetic is about generating new backup on the backend of a Netbackup Master/media server (creating new backup for files already in the Netbackup enviroment).

Hope this clarify