Deferred Import
The deferred
import is a process of historical data transfer after the successful upgrade or
migration of a
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 or
upgrade 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 upgrade or migration. The historical
data transfer and deferred import of historical data are disabled by default.
You can enable and configure the historical data transfer by using the API,
,
installer, or CLI installer. A
super
administrator can run and control the migration, upgrade, 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 upgrade or
migration and when the
instance is running. You can pause the historical data import and resume it
later.
For information about how to
configure and run the migration, upgrade, 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
Class Diagrams and Workflows for Deferred Import
and 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 upgrade or 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
root
credentials. If you send requests to the
reverse proxy port, you must authenticate with
credentials.
The following HTTP requests show
the syntax that you can use to perform the available user operations.
https://<IP_of_upgraded_or_migrated_instance>:5480/rest/vcenter/deployment/history?action=pause
https://<IP_of_upgraded_or_migrated_instance>:5480/rest/vcenter/deployment/history?action=cancel
https://<IP_of_upgraded_or_migrated_instance>:5480/rest/vcenter/deployment/history?action=resume
https://<IP_of_upgraded_or_migrated_instance>:5480/rest/vcenter/deployment/history
https://<IP_of_upgraded_or_migrated_instance>/rest/vcenter/deployment/history?action=pause
https://<IP_of_upgraded_or_migrated_instance>/rest/vcenter/deployment/history?action=cancel
https://<IP_of_upgraded_or_migrated_instance>/rest/vcenter/deployment/history?action=resume
https://<IP_of_upgraded_or_migrated_instance>/rest/vcenter/deployment/history
For information about the status
codes and historical data transfer errors, see
HTTP Status Codes
and
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 upgrade or migration process.