The vCenter Server Appliance instance requires a database to store and organize server data. Ensure your source vCenter Server database is prepared for migration to the target vCenter Server Appliance.
Each vCenter Server Appliance instance must have its own database. The bundled PostgreSQL database that is included in the vCenter Server Appliance supports up to 2,000 hosts and 35,000 virtual machines.
To ensure your database is prepared for migration:
Verify that passwords are current and not set to expire soon.
Reduce the database size. For more information, see http://kb.vmware.com/kb/2110031.
For vCenter Server 5.5, run the cleanup scripts to remove any unnecessary data in the vCenter Server database using the steps for your database. For details see:
Verify that you have backed up your database. See your database documentation.
Verify that vCenter Server can communicate with the local database. See Verify That vCenter Server Can Communicate with the Local Database.
During the migration of vCenter Server to vCenter Server Appliance, the installer:
Exports the vCenter Server database.
Deploys the target vCenter Server Appliance in an unconfigured state.
Copies exported data to the target vCenter Server Appliance.
Starts the PostgreSQL service to import the source database data.
Upgrades the database schema to be compatible with the target vCenter Server Appliance.
Starts the target vCenter Server Appliance services.
When you configure the target vCenter Server Appliance, you initialize and configure using the imported database with the old schema. You have a choice of migration options:
Inventory tables with events and tasks
All database data