Typically, data transfer happens as part of the upgrade downtime. However, in some scenarios you can choose to transfer a part of the data after upgrade or migration to minimize the downtime.

Transfer of data after upgrade or migration is supported in the following scenarios:

  • Migrating vCenter Server for Windows to vCenter Server Appliance

  • Upgrading vCenter Server appliance with external database

    Note: You can only transfer data from external database to the embedded PostgreSQL database in the background after upgrade or migration. Transferring data from an embedded PostgreSQL database to another embedded PostgreSQL database after upgrade or migration is not supported.

You can transfer the minimum amount of data necessary to be operational during the upgrade. Later, you can transfer the remaining data from the external database to the embedded PostgreSQL database in the background, preserving your deployment's historical event and performance data.

You can transfer historical data after the upgrade or migration from the following vCenter Server versions using external databases to the embedded PostgreSQL database within the vCenter Server appliance.

Table 1. vCenter Server Database Support for Data Transfer After Upgrade or Migration
vCenter Server Versions Databases Support for Data Transfer After Upgrade or Migration
vCenter Server appliance 6.5 Embedded PostgreSQL database Not Supported
vCenter Server for Windows 6.5 External Oracle or MS SQL database Supported
Embedded PostgreSQL database Not supported
vCenter Server appliance 6.7 Embedded PostgreSQL database Not supported
vCenter Server for Windows 6.7 External Oracle or MS SQL database Supported
Embedded PostgreSQL database Not supported
You can transfer the following types of data from an external database to the embedded PostgreSQL database in use by version 7.0 of the vCenter Server appliance.
Configuration data
The minimum type of data you must transfer from your existing vCenter Server appliance external database to upgrade or migrate to a functioning vCenter Server appliance. This data can be transferred in a reasonably short amount of time, minimizing downtime during the upgrade to vCenter Server 7.0.
Configuration and historical data
In addition to the configuration data, you can choose to transfer historical data such as usage statistics, events, and tasks. The vCenter Server installer gives you the option to copy both the configuration and historical data at one time, or to copy only the configuration data during the upgrade process. You can then choose to copy the historical data in the background after you start your new vCenter Server.
Attention: If you choose to copy all data at one time, you cannot start vCenter Server until all the data has been transferred to the embedded PostgreSQL database within vCenter Server 7.0.
Configuration, historical, and performance metrics data
The largest amount of data you can choose to transfer to vCenter Server. You can copy only the configuration data during the upgrade process, and then copy the historical and performance data in the background after the upgrade or migration to vCenter Server 7.0 finishes.

Monitor and Manage Historical Data Migration

You can monitor and manage the background migration of historical data using the vCenter Server Management Interface. You can perform the following data management tasks:
  • Monitor the progress of the data migration.
  • Pause the data import.
  • Cancel the data import.
    Important: If you cancel the data import, the historical data is not imported to the embedded PostgreSQL database. If you cancel the data import operation, you cannot recover the data. If you do cancel the data import, and want to import the historical data later, you must restart the upgrade or migration process from Stage 1 of the GUI installer.
See Monitor and Manage Historical Data Migration.