This article explains a situation which can occur when performing a migration to PST using the Native Format Import Module with Archive Shuttle and using one or more mappings with multiple filters against the same containers.
Sometimes when processing a large archive, and directing the migration to the Native Format Module to create PSTs that large archive (container) is mapped multiple times with different filters. This requires a file name policy to be chosen as part of the mapping.
A common file name policy which is chosen is:
This will lead to a problem because the uniqueness (pstnumber) is only PER MAPPING, not across all mappings. Errors such as this will be logged in the Native Format Import module log file, and eventually, the migration will stop.
A better mapping to choose is one which involves pstid. eg: