The scanning of SharePoint directories is very slow.

Question / Problem

The scanning of SharePoint directories is very slow.

Answer / Solution

This problem is unfortunately caused by SharePoint itself.

SharePoint throttles the number of user actions for very large requests. This leads to the fact that TreeSize has to pause the scan after a certain number of calls for a short time (40 to 300 seconds) until new user requests are released.
If SharePoint interrupts the active scan due to too many calls, a message is written in the Windows Event Viewer that refers to the throttling.

To speed up or not unnecessarily slow down a scan, unused statistics (esp. the statistics on file owners and the option to 'Track advanced file system features') should be deactivated.

As an alternative, SpaceObServer may be interesting for you, as it also supports SharePoint scans. Due to the database used to persist the scan results, the data collecting process, and the reporting/analysis can be split up into two independed steps. Let the scan-service wait, instead of waiting yourself.