The console takeover and recovery function supports Operations Console workstations and the 5250 emulator on the Hardware Management Console (HMC) Console. Takeover is also supported in a D-mode IPL. Two devices can be connected, with data, at the same time during a D-mode IPL, but only one device can be the console at one time.
The takeover function is the process used for a LAN-connected, console-capable device to take control from the current LAN-connected console device. Because there can be only one local console that is directly attached and the HMC 5250 emulation console can be shared, the takeover function cannot be used with the local console that is directly attached. However, any 5250 emulation-based device can be used to recover a loss of the console by changing the console type. The twinaxial console uses a special form of 5250 emulation and does not qualify as a console type to switch to or from without loss of data. This might require a reallocation of hardware to support the new console.
The recovery function is accomplished by suspending the data stream to the console that either loses its connection or is in the process of being taken over. Then it saves the data to be delivered when the next device becomes the console. This process takes place even if the newly established console is the same as the former console.
Console recovery uses part of the takeover function. Recovery can be from the same device or another 5250-based device. For example, if you are using a local console on a network (LAN) and have multiple PCs set up to be the console, and the existing console fails, you can use the takeover function from the same PC (after correcting the reason for the failure) or from another PC. Regardless of what the former console was doing, the new console is in the same job, at the same step, as the original console. The job continues even though the original console is not operational.
The current console type is still the only console allowed when takeover is enabled. However, each console-capable workstation is presented either a DST Sign-on window or the Console Information Status window. If the console is set to Operations Console (LAN), for example, a local console that is directly attached is presented the Console Information Status window without displaying the DST Sign-on window. The Take over the console field displays NO to indicate it cannot take over the existing console. However, it can be used for a recovery action. When the console type is not set to be the HMC (4), the HMC 5250 emulator posts a Connection refused - partition not configured for HMC console message.
Every console-capable device that can support 5250 emulation is presented with a window of data regardless of its specific connectivity and regardless of whether it is the console at the time it connects successfully to the server. This means that more than one device has data on the screen after the console is established. A console-capable device no longer displays a blank screen and a Disconnected state when another device is the active console. Instead, the device displays an error message (HMC) or the Console Information Status window. The key feature of this function is that it allows the job running at the console to be "transferred" to another device without loss of data.
Consider the following restrictions before enabling the console takeover and recovery function.
The default setting for the console takeover and recovery function is disabled. If this function is disabled, all console-capable devices display the Console Information Status window whenever they are not the active console. When the console is set to a 4 (HMC), a local console directly attached device does not automatically connect. An Operations Console LAN-connected device only starts if the network adapter has a valid configuration, such as that provided after configuring the service tools server for iSeries™ Navigator.