The wish to perform a migration project from single-master to multi-master mode might arise when a CoreMedia CMS system is extended to host an intranet application besides an existing Internet web server. It is also possible that multiple sites that were previously hosted on different servers are about to be unified on a single system.

In multi-master mode, all content that belongs to a publication target should reside below a single top-level folder. Therefore, the main target of the migration is to modify the repository structure to reflect this requirement.

Before the migration, the repository might look like this:

/
+--Articles
+--Home
+--Inbox
+--News
+--Pictures

Afterwards one more folder has been introduced that hosts most of the repository’s content.

/
+--Home
+--Live
   +--Articles
   +--Inbox
   +--News
   +--Pictures

After determining the new repository structure, the main step of the migration is handled by the cm multisiteconverter tool, which updates the database. Still, care has to be taken, because the Content Management Server has to be down while doing the conversion. For typical CoreMedia CMS installations a considerable number of servers, CAEs, and importers is deployed and an extended downtime that is noticeable to the content consumers is not acceptable. A migration path will be shown, that keeps the visible downtime low.

There will be certain aspects of the process described in the following sections that are not directly applicable to your installation. It is therefore important to spend enough time on finding a process that meets your needs, before starting the actual migration project.

For a start, assume that you are migrating to the CoreMedia Multi-Master Management without changing migrating to a different release at the same time. If you want to do so to avoid multiple downtimes, see Section 3.10.4.4, “Updating Simultaneously”. Furthermore, assume that the content that is currently stored in the existing Content Management Server should go to a single Master Live Server, so that you are free to add further Master Live Servers later on. If you want to distribute the existing content over multiple Master Live Servers, see Section 3.10.4.5, “Splitting Content to Multiple Targets” for details.