Logic when storing directory structure information in the database

migRaven is optimized for traceability of structural changes. The directory name is the most volatile value in the directory structure.

In the migRaven "managed folders" should be clearly recognizable in order to be able to clearly assign all changes.

Managed folders by migRaven are:

• Directories that have been assigned a data owner (more info)
• Directories over migRaven were generated (more info)
• Directories whose permissions over migRaven were managed (more info)
• Directories that have been assigned tasks (more info)
• Directories that have been archived via an AdHoc archiving job (see one-time data retention)
• Directories that are handled via a regular archiving job (see regular data retention)
• Directories that have been deleted. (more info)

Therefore, during the file server scan:

• renamed directories on the same volume are recognized
• moved directories on the same volume are recognized
• managed folders by migRaven reliably identified when they are moved to other SDD and thereby the Directory ID and Volume Serial changes. 

The primary key for directory identification is a combination of the following three values:

1. Directory ID of the SDD
2. Volume Serial of the SDD
3. directory name

The following logic applies when saving directories:

1. Combo of [Directory ID + Volume Serial] + Directory Path
2. if a managed folder from the database with the combination of step 1 appears during the scan, then this directory is moved to a special archive area of ​​the database.
3. In the aftermath of each FS scan, the nodes from the archive are compared with the new directory node in the DB
4. If a match is found based only on the [Directory ID + Volume Serial] combination, the values ​​are reassigned to the new node in the DB
5. If a match is found in the directory path with a different volume serial at the same time, the values ​​are also adopted.
   This step covers the following scenarios:
   • The volume on which the data was previously located is replaced. Normal migration case: old server -> new server
   • Certain constellation when using DFS with several configured namespace servers. This is a normal situation. migRaven can be scanned through namespace server A or any other. In each of these cases, the [Directory ID + Volume Serial] alternate.