This article explains how permissions are migrated when migrating to Google Drive, OneDrive or Sharepoint libraries.
Permissions are preserved during a file migration.
- Each individual entry in the permissions list must exist in the target.
- If the source email is different from the target email, a mapping table must be used and correctly filled.
The mapping table is the migration list itself.
The migration list is used as mapping table to migrate permissions when source and target emails are different.
You can also add entries in it without assigning licenses in order to map groups and users you don’t plan to migrate.
If an entry is missing, (unless source and target emails are identical), the individual permission will not be migrated.
Therefore, the mapping table must be complete from the beginning of the migration (even during the trial if wish to evaluate this functionality)
Permissions are not remigrated when a file is modified.