You want to troubleshoot or monitor an index upgrade task.
The Upgrade wizard lets you upgrade 32-bit index volumes to 64-bit.
The Upgrade starts by putting the original volume(s) into read-only mode. A new, hidden, volume is then created and items start to be added to it. During that time, progress of the upgrade and details of any failed items will be recorded in the report.
The old index volume(s) remain searchable during the upgrade to avoid impact on users.
If indexing is distributed across a group of servers, the Upgrade task will run on the server that’s been chosen to host the new index volume.
Once the upgrade has completed successfully, the old index volume will be replaced with the new volume, which at that point becomes searchable. The old volume(s) will be deleted.
To troubleshoot or monitor the progress of a running Upgrade, use Dtrace to monitor the following processes: