Scenario: LAN connected devices only with takeover enabled

 

This scenario describes what happens during an IPL when console takeover is enabled and more than one LAN-connected device is available.

The LAN devices are called LAN1, LAN2, and LAN3. The IPL is being performed in unattended (Normal) mode.

At the point in an IPL when the console device is being determined, it is more or less a race condition if more than one device is connecting at a time. The first device to connect, of the type specified by the console type setting (LAN in our example), becomes the console and will be presented with the usual console screens.

For our example let's say LAN1 is the first device connected. During the IPL this device will show the IPL status changes just like any other console and eventually the i5/OS^® sign on window. LAN2 and LAN3 will show a special DST signon screen with a new line of data stating ATTENTION: This device can become the console. The rest of the window will be the same as any other DST signon window. At LAN2 a user with the user privilege of take over console signs on. This user will now be presented the same Console Information Status screen and the take over the console field will show a YES indicating that takeover is possible. At LAN3 a user without the take over console privilege signs on. The take over the console field will show as NO since the user does not have the correct authority for takeover.

At this point, only one device has met all the conditions for a console takeover. At the bottom of the window is F10 (Take over console connection). Pressing F10 presents the user with the Take over Console Connection From Another User window. This is a confirmation window that gives the user a last chance to cancel the takeover. Selecting 1 and then pressing Enter at this point causes the takeover to occur. Almost immediately, LAN1 gets the special DST sign-on window and LAN2, the device that initiated the takeover, has the exact same window that LAN1 had when the transfer took place. The job, if something was running, does not know that this action took place. In fact, the original console could have been installing Licensed Internal Code or the i5/OS operating system, or it could have been running a complete system save in restricted state and the system does not know it. You can even disconnect the console connection and come back later, reconnect, and you can still get the current job's window data. If a large amount of window data was sent by the job and could not be delivered, the data will be stored until later. When a console is reconnected by an authorized user (has the takeover console privilege) from an eligible device, the user might see fast window refreshes until all the stored data has been delivered. Actually, doing a disconnection and a reconnection is considered a recovery (not a takeover).

The data present at LAN3 will not change after the takeover. Currently, there is no method to automatically refresh the data. However, if the user at LAN3 pressed Enter, a manual refresh of all fields except the Take over the console field would occur. The user would have to exit this screen and sign on again to see the change to that field.

 

Parent topic:

Scenarios: Takeover and recovery