Several times while performing a Notes DB scan, Migrator for Notes to SharePoint stops. If the Discovery is restarted most of the time it completes. The Repository has 34k databases 21k unique replicas (the headers are also being scanned).
We recommend that you break up the Discovery to different migration machines based on regional locations. Then try to place migration machines in each region. That may assist to determine if there are particular Notes databases causing the scanning process to fail. Performance of the scanning process is dependent on:
1. Network bandwidth and speed (and reduced hops)
2. Server performance and response time
3. Migration machine CPU and memory capacity
4. Migration machine disk speed
Assigning more migration machines to scan the Notes application environment will complete the process faster. Especially if they are located physically close to the Domino servers.