What is controller takeover? When does it occur?
Controller takeover takes place if one controller unexpectedly fails. The other controller will automatically take over all of the tasks of the failed controller to ensure uninterrupted services.
Depending on the traffic at the time of takeover, controller takeover may take between 30-60 seconds. During this time, data access will be momentarily paused, but not interrupted. Users should be able to continue using the system without realizing that takeover is in progress.
Controller takeover will take place automatically under the following 2 circumstances:
- If one controller fails and does not respond.
- When the user manually activates takeover on the management interface.
Controller takeover can be activated under the following 2 circumstances (the default setting is “disabled”, but the options can be customized):
- The network connection on one controller is interrupted.
- The JBOD connection is interrupted on one controller.
Controller takeover will not be executed under the following 4 circumstances:
- BBU failure.
- PSU failure on one controller.
- Fan failure.
- Drive failure.
Users can manually activate takeover on the management interface.
