Plan for your backup console

Most system plans include a level of redundancy to allow for the event of hardware failures, however many people do not consider the console in their plans. You should plan to back up your console information to recover quickly from an unexpected loss of the console.

Considerations for a backup console:

• The adapter location is fixed or at least limited for independent servers or primary partitions. Based on your server's hardware requirements you may have limited choices of console types. Try to accommodate at least one additional console type, if possible.
• Consider using the take over and recovery option as part of your backup console strategy. However, the hardware used for the new console mode must exist and be available at the time of recovery. For more information about take over and recovery see the section: Take over or recover an Operations Console connection.
• If you are working in a partitioned environment, consider:
  • In an LPAR environment, the term "alternate console" is referring to the twinaxial console type located in another IOP tagged as the alternate console. If a failure of the primary console is detected, the system will automatically try the alternate console's IOP. This function gives you another level of protection. Tagging a single IOP as both the primary console and the alternate console can result in the inability to select a console. Further isolation can be planned by placing the alternate console IOP on a different bus so that failures of the primary console's bus will not prevent a console from being available.
  • Models 270 and 8xx are tagged for a console type only at the IOP level. Placing two like console adapters, for example two 2849s or two 2771s, for the same IOP can sometimes make it difficult to determine, in advance, which adapter will be used for the console. IBM recommends only one console adapter for the IOP tagged as the primary console to support Operations Console. The lowest addressed adapter on the bus will be attempted first but if that adapter is slow reporting to the system another adapter might get selected instead.
  • Consider a shared resource environment in which you can allocate and deallocate a console supporting IOP to a partition on a part-time basis. Many work environments rarely need a console device on a full-time basis and you can reduce your initial cost of dedicated hardware by implementing this concept.
  • If the load source storage device fails and the system recovery will include the use of the IBM^® distribution Licensed Internal Code media instead of a customer backup, and the system is using Operations Console (LAN), you may have to use another console type for the initial portion of the system recovery.

Planning configuration types for backup consoles:

Backup console configuration considerations:

• If you access your server remotely, consider off-site console capability or another connectivity for the console. A local console on a network can be backed up with additional local console on a network PC. If the network adapter were to fail, consider a local console directly attached to the server as a backup. By changing the console type to a local console directly attached to the server with remote access, you can add the ability for a remote PC to become the console.
• In an LPAR or multiple server environment you will most likely be using multiple local console on a network configurations on a single PC as your primary consoles. Consider additional PCs using this same type configuration. Avoid supporting too many consoles on the same PC if possible. The PC resources can be easily overwhelmed when supporting multiple consoles and remote control panels.
• Consider multiple local console on a network configurations in large environments so that each PC has a core set of console responsibilities and the overlap coverage of backup configurations with each other. For example, if you have a PC that supports 10 local consoles on a network configuration and another PC with the same number of primary consoles for another 10 partitions, instead of backing up each PC with the other's configuration, you add a third PC and spread the 20 consoles out so that two PCs back up a portion of each PC's primary console configurations. Another consideration is a dedicated PC to be the backup of a certain number of consoles, but not connected until necessary.
• When using mostly networked consoles, consider setting up a local console directly attached to the server on a PC and place it on a rollaway cart with a console cable. If you have supporting adapters, you can quickly roll the cart with the PC near the server or partition in need of the console. After connecting the cable and changing the console mode value, you have a console to replace the currently failed console. This same concept can be implemented for twinaxial workstations just as easily.

In summary, consider incorporating as much redundancy as possible into your console configuration. If you consider the question, "What happens if this fails?" and you have another method to provide a console in place, and if you make compromises and adjustments for the various hardware requirements necessary to overcome the various levels where a failure might occur, you will reduce your exposure to a catastrophic console failure situation.

For more information on switching between console devices, see: Managing your multiple consoles.