Preparing for the Migration
The number of threads to be used for migration should be set before the migration starts. The migration service scheduling or the maximum size of documents migration queue can however be modified in the middle of the migration.
You can adjust different parameters to control when the migration runs, and how much load on PPM Server it might generate.
In addition, you can do the follows.
Estimate the Migration Duration
To help estimate how long the migration may take, you may run some SQLs to count documents and to estimate total size of files in the system:
To count how many documents are in the system, run the following:
SELECT COUNT(*) FROM KNTA_DOCUMENTS
To count how many document versions are in the system, run the following:
SELECT SUM(VERSION_NUMBER) FROM KNTA_DOCUMENTS
To estimate the total size of files in the system, run the following:
SELECT SUM(FILESIZE*VERSION_NUMBER) FROM KNTA_DOCUMENTS
Note: Normally 1 GB of data (around 3000 documents with the average document size of 333 KB) can be migrated in less than 10 minutes.
Configure the Migration Background Service
To schedule the DMS Migration Engine Service,
Log on to PPM.
On the Open menu, click Administration > Schedule Services.
The Schedule Services page lists all of the available services, and shows the typical load each service manages, whether the service is enabled, the type of expression used to schedule the service, and the current run schedule.
Locate and click the DMS Migration Engine Service.
From the drop-down list in the Status column, select Enabled.
To select a schedule type, do one of the following:
To use a simple expression such as hours, minutes, or seconds to schedule the service, in the Schedule Type list, leave Simple selected.
To use a cron expression to schedule the service, from the Schedule Type list, select Cron.
Note: For detailed help with scheduling the service, next to the Schedule Type list heading, click the help icon after the Schedule Type column heading.
In the Schedule column, provide the simple or cron value to specify the DMS Migration Engine Service run interval.
In the top right corner of the page, click Save.
All the nodes configured to run PPM heavy services eventually run migration service as scheduled. So migration can eventually run on multiple PPM nodes if more than one node is configured to run heavy services.
The DMS Migration Engine Service is automatically enabled when you click Start Migration in the Administration Console, and disabled when you click Cancel Migration or Commit.
The schedule should be set in accordance with the migration batch size. It can negatively impact the speed of migration if the documents migration queue runs out of documents to migrate before the service is re-invoked.
If the migration service is invoked on a node where the documents migration queue is not empty, it fills the queue so that the total number of documents in the queue matches the migration batch size.
When a migration is in progress, disabling the DMS Migration Engine Service terminates the migration. However, you should use the Pause button if you want to pause the migration. This is more efficient, as simply disabling the service would still need to wait for all documents in the queue to be processed.