Deferred Import
The deferred import is a process of
historical data transfer after the successful migration of a
vCenter Server
instance
with an external database. The historical data includes statistics, events, and tasks. By using the deferred import feature, you can postpone
the historical data transfer after the migration process completes, so that you manage
the downtime of your environment. You can select whether all historical data, or only
events and tasks, will be migrated with the core data during the migration. The
historical data transfer and deferred import of historical data are deactivated by
default. You can enable and configure the historical data transfer by using the API,
,
vCenter Server
installer, or CLI installer. A vCenter Server
super administrator can run and control the migration and
deferred import processes. If you use the deferred import feature, the historical
data is migrated with the core data and the historical data import process starts
automatically after a successful migration and when the
vCenter Server
instance is running. You can pause the historical data import and resume it later. For information about how to configure and run the
migration and deferred import processes by using the , see the
vCenter Server Upgrade
documentation. By using the API, you can configure, control, and
monitor the data transfer process. If you use the API to enable the deferred import
feature, you must create a history migration spec and set
defer_import
to true
. For information about
how to configure the deferred import by using the API, see the API reference
. The data import process has five states that you can
check. If the historical data migration and the deferred import are configured, the
historical data import starts automatically after a successful migration.
Deferred Import State
Diagram
Operation
| Description
|
|---|---|
Pause
| You can pause the running data transfer
process. If the data transfer is paused, you can resume or cancel it.
|
Cancel
| You can cancel the data transfer process if it
is in a
RUNNING or
BLOCKED state.
If you cancel the
data transfer, the process enters in a final
FAILED state and you
cannot resume the transfer.
|
Resume
| You can resume the stopped data transfer.
|
Get status
| You can retrieve the
status of the data transfer process. There are five states.
|
You can run the deferred import
operations by using the API or sending an HTTP request.
When you send the
requests, you must use an authentication.
If you send requests to port
5480
, you must authenticate
with vCenter Server
root
credentials.
If you send requests to the vCenter Server
reverse proxy port, you must authenticate with vCenter
Single Sign-On
credentials. The following HTTP requests show
the syntax that you can use to perform the available user operations.
https://<IP_of_migrated_instance>:5480/rest/vcenter/deployment/history?action=pause
https://<IP_of_migrated_instance>:5480/rest/vcenter/deployment/history?action=cancel
https://<IP_of_migrated_instance>:5480/rest/vcenter/deployment/history?action=resume
https://<IP_of_migrated_instance>:5480/rest/vcenter/deployment/history
https://<IP_of_migrated_instance>/api/vcenter/deployment/history?action=pause
https://<IP_of_migrated_instance>/api/vcenter/deployment/history?action=cancel
https://<IP_of_migrated_instance>/api/vcenter/deployment/history?action=resume
https://<IP_of_migrated_instance>/api/vcenter/deployment/history
For information about
the historical data transfer errors, see Historical Data Import Errors.
If you pause the data transfer
by using the API or an HTTP request, you can resume or cancel the process by
using the API or the
.
If you cancel the transfer
process, and want to transfer the historical data later, you must restart the migration
process.