Console planning considerations

The following information applies to all servers:

• Unlike previous versions of i5/OS™, this release and subsequent releases will support only the console type that is currently configured. If no console type is specified, such as when a new logical partition is being created, the supporting hardware IOP specified during the creation process takes precedence. If the supporting hardware contains more than one console type, then the first console workstation to connect will be configured to become the console.
• There is also a special set of console options called Allow console to be taken over by another console. This set of functions allows Operations Console to take control from another console device. The default value of this console option is disabled.
  • When the option is enabled:

    The first Operations Console device connected becomes the console. Additional LAN-connected Operations Console devices will have a special DST signon.

    All other 5250-based connections will have the new Console Information Status window.

    Console recovery without the loss of the job is available.

  • When the option is disabled:

    All 5250-based connections will be presented the new Console Information Status window.

    Console recovery without the loss of the job is not available.

• Operations Console, both direct attached and network (LAN), and twinaxial workstations, can coexist as console devices if you remember these rules:
  • Only one device can be active at a time.
  • A twinaxial workstation on any twinaxial workstation controller adapter with port 0 (addressed either 0 or 1) or port 1 (addressed either 0 or 1) can become a console device if twinaxial console is the console type selected. If twinaxial console is selected as the console mode then Operations Console devices may not be started.
• Operations Console allows multiple LAN connections to a single server or logical partition, but only one 5250 session can have control of an server at a time. An active console is the command interface to a server through 5250 emulation or IBM^® Personal Communications that is currently interacting with the server. More than one Operations Console device may have data on the screen but only one is truly active.
• The client PC also allows multiple local console connections but allows only one local console directly attached to the server configuration (or local console directly attached to the server with remote access allowed) for a single PC.
• There is a maximum of 26 Operations Console emulator sessions available per Operations Console PC client.
• IBM recommends that you do not put your Operations Console on the same IOP as storage devices.
  • There may be configurations when this cannot be avoided.
  • During very heavy usage of storage devices the console may appear to stop working temporarily but should resume operation shortly. If the console is placed on the same IOP as storage devices it is highly recommended that you enable the new console option, Allow console to be taken over by another console.

The following information pertains to console takeover and recovery:

In V5R4 and later releases, there is a special set of functions known as console take over and recovery, that allows a LAN-connected Operations Console to take control from another console device. Use the following information to help determine what console devices are best for your work environment and how to deploy these devices to take advantage of the new functions.

• Takeover is the process used for a LAN-connected console device to take control from the current console device. The user signed on to the PC that wishes to take control requires special authority and is initiating the takeover from a new menu. This takeover function is not used for directly attached consoles.
• Recovery is the process of regaining control of the job running on the console after a problem with the console was encountered. The recovery process may be to the same console device or a different console device and may be facilitated by additional work to enable a device using a different connectivity. The exception is twinaxial console which does not use the same type of 5250 emulation and thus cannot recover the console without data loss.

When the takeover option is enabled and the device is properly connected, each console capable device running 5250 emulation, regardless of connectivity, will be presented a screen of data regardless of whether or not it is the active console. In V5R3 and later releases, more than one device will have data on the screen after the console has been established. There will be no more blank console screens showing Disconnected when initially connecting a device. The new function now allows the job at the console to be transferred to another device without causing loss of data.

This function is accomplished by suspending the data stream to a console that loses a connection or is being taken over, save further data and then send that data to the next device to become the console, even if the device is the same former console. Recoverability is essentially taking over the console from the same or different qualified device regardless of what the former console was doing.

The following information pertains to independent and primary partitions:

• Console supporting hardware may be required to be located in specific slot locations, based on model.
• Multiple IOPs capable of supporting a console workstation can interfere with the selection of the desired LAN adapter. Consider the following:
  • Having a second IOP on the bus before your intended console adapter card, when the first IOP contains a twinaxial adapter card, may fail to provide a LAN-connected console. For example, a model 890 uses eligible card locations C04, and C06 through C10 and if an IOP were placed in C08 and a twinaxial adapter preceded this IOP on the bus then the LAN adapter card located at C09 or C10 will fail to provide a LAN-connected console. The LAN adapter card must be in a location preceding the second IOP, such as C06 or C07.
  • Typically, the card location used for Operations Console directly attached configurations, commonly referred to as the Electronic Customer Support (ECS) slot, is located close to the beginning of the bus. When the card location is a low number, for example C02, then C03 is further from the beginning of the bus than C02. When the card location is a high number, for example C07, then C06 is further from the beginning of the bus than C07. There may be exceptions to this numbering scheme based on specific models and expansion units. Contact your service representative if you have questions about the placement of the ECS.

The following information pertains to a multi-partitioned environment:

• If you plan to use Operations Console as your primary console or as a backup console, you must tag the IOP to support the primary console and Electronic Customer Support (slot), even if you do not plan to use Electronic Customer Support. For example, if you are planning to use Operations Console on a direct connection, you must tag an IOP with the console tag and the ECS tag. These steps are also necessary if you are planning to use Operations Console with a LAN connection.
• When more than one console adapter is available for a single IOP, the adapter with the lowest bus address will be chosen for use by Operations Console. For example, you tag an IOP that has two LAN adapters installed. The system will use the first adapter found on the bus. However, during an IPL the first adapter may not be ready in time and the system could select the second adapter. This could prevent the console from starting immediately or you might not be able to use that resource for your intended purposes. IBM recommends that you install only one console-capable adapter that matches your configurations for a single IOP. This situation also will affect asynchronous adapters used by a local console directly attached to the system.
• The term alternate console is referring to a twinaxial console type located in another IOP tagged as the alternate console. Operations Console and HMC type consoles do not use resources tagged as the alternate console.
  Note: Tagging the same IOP as both the primary console and the alternate console may result in the inability to select a console. If you have a twinaxial adapter in the same IOP as your primary console's adapter, consider the twinaxial adapter to be a backup console, not an alternate console. You only have to change the console mode to take advantage of the twinaxial adapter for the console.