I got caught out when enabling the Document ID service for SharePoint 2010 trying to understand why instantly after enabling the feature my documents did not have unique ID's so I thought I'd write a quick blog on how to do this.
Navigate to the site collection that you require the Document ID Service to run on and activate the Site Collection Feature as shown below.
Again from Site Collection Administration navigate to Document ID settings as highlighted in red below:
From this section you can provide a predefined document ID naming prefix to suit.
If you have existing documents in the documents in the site collection there is also the option to reset all the document ID's with the new naming prefix.
So at this stage you would assume that the document ID's are there when you visit a document center after enabling the
settings above? Wrong! Although this feature has been activated the process of assigning the ID's to documents has not yet been run and this is carried out via a SharePoint Timer Job.
Navigate from Central Admin to monitoring then click Review Job Definitions.
From the list here make sure the correct web application is selected in the top right.
Then run the Document ID enable/disable job. This basically propagates changes to content types across all sites after the Document ID feature has been reconfigured.
Once this Timer Job has run (depending on how many content types you have created should not take long) you then need to run the Document ID assignment job which will assign document ID's to all items in that specific Site Collections.