Here’s a quick SQL query to show the status of currently active mailbox index movement tasks:

select * from TaskStatus
where TaskName = 'IndexMove'
AND ProcessedCount = 0
AND FailedCount = 0

Note that the ProcessedCount will equal 0 for all currently active jobs and previously failed jobs. To list failed mailbox index relocation attempts, set the FailedCount = 1, e.g.,

select * from TaskStatus
where TaskName = 'IndexMove'
AND ProcessedCount = 0
AND FailedCount = 1