Reindexing and Fast Archive Scanning in Nx Witness

What is an archive index and what does reindexing do?

Nx Server creates a database that stores an index that maps the relationship between archive filenames and the physical location of the archive on the storage drive. Reindexing restores the relationship between the database and storage drive. This process can take up to several hours, depending on the size of the archive. 

The Nx Witness system can still be used during this process and will continue recording while the archive is reindexed as long as the storage drive has enough capacity to do both simultaneously (performance may be affected).

When should I reindex an archive?

Reindexing should be performed when the index is broken, which can occur when

• a camera is deleted; or
• a storage device is moved, renamed, or deleted; or
• an archive file is removed, renamed, has an incorrect timestamp, or is otherwise corrupted.

When an archive is damaged, administrators will receive a notification when attempting to view that archive. The notification indicates the storage path where the problem was detected.

When a camera is deleted, its archive remains, but access to the footage is lost. After reindexing, Nx Desktop will display the deleted camera in the Resource Tree as an offline device so that it is possible to navigate through its archive.

What happens during a fast archive scan?

A fast archive scan checks to see that the database is intact and matches the archive. This process usually only takes a few seconds and occurs automatically when Nx Server is initially started or restarted at any point afterward, an archive file closed improperly, or the index files cannot be read.

During a fast archive scan, recording will be put on hold and resume after the process is complete. There are a few situations where a fast archive scan may take much longer than anticipated, such as when there is an extremely large archive, the server database was moved while the server was offline, or an archive from another server was transferred over to this server prior to its initial launch.

To reindex an archive

1. Right-click on a server in the Resource Tree and choose Server Settings. Go to the Storage Management tab.
2. Perform one of the following actions:
• Click Reindex Archive to restore the index for all Main storage locations.
• Click Reindex Backup to restore the index for all Backup storage locations.
3. A message will open with the warning "Hard disk load will increase significantly". Click OK to continue. 
4. When the window closes, reindexing will run in the background. A progress bar will indicate its status, and you will see a message when reindexing either completes successfully or has been canceled:
• If the archive reindex is canceled before it completes, Nx Server will show a system-generated event in the Notification Panel called "Rebuilding archive index is canceled by user". The archive index can be canceled at any point, and an incompletely indexed archive may be partially or entirely inaccessible. It is strongly recommended that the reindexing process is allowed to be completed. 
• If the archive reindex completes successfully, Nx Server will show a system-generated event in the Notification Panel called "Rebuilding archive index is complete".

Questions

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