Using the recover mirrored load source function

The recover mirrored load source function is used after a local load source failure to recover both the system and user data from the remote load source and to copy the data to the new local load source.

Recover mirrored load source assumes that the load source used for the initial program load (IPL) is new and has just been installed. This should be true whether recovering after a site disaster or after a local load source failure. After the new load source is installed and the system IPLs to dedicated service tools (DST), recover mirrored load source finds the remote load source and then synchronizes the new load source from the remote load source. When the synchronization is complete, the system re-IPLs automatically, because the Licensed Internal Code that was copied onto the IPL load source during synchronization might be different from the code used to IPL to DST.

Recover mirrored load source requires the following conditions:

  • The current load source must have just been installed.
  • The system must be able to find a valid configuration on the other disk units that are attached to the system.
  • In the recovered configuration, remote load source mirroring must have been enabled.
  • In the recovered configuration, the system ASP and the load source must have been mirrored.
  • The remote load source must be attached to the system, it must be functional, and its mirrored unit state must be active; that is, it must contain current data.

To use the recover mirrored load source function, follow these steps:

  1. From the Dedicated Service Tools (DST) Main Menu, selection option 4, Work with disk units.
  2. From the Work with disk units menu, select option 2, Work with disk unit recovery.
  3. From the Work with disk units recovery menu, select option 16, Recover mirrored load source.

    The system checks to see if it is possible to recover the mirrored load source. If recovery is possible, the system finds the best recovered configuration, finds the remote load source to use for recovery, and verifies that the remote load source and other disk units of the configuration are functional.

    • If the mirrored load source can be recovered, the system will show a confirmation display that indicates the configuration that will be recovered.
    • If the mirrored load source cannot be recovered, the system will display an error message. Follow the recovery actions that are listed for the error, and resolve the problem, if possible. If it is not possible to recover the mirrored load source, the data in the system auxiliary storage pool (ASP) will be lost. If other ASPs in the system are intact, you can use the Recover Configuration function to recover the system configuration and the data in the complete ASPs.
    • If the mirrored load source can be recovered, but there is not an active, usable disk unit present for each configured logical unit of the system (at least one active unit of each mirrored pair present and all device parity and unprotected units present), then all data will be lost in ASPs that have missing units.

    The system will display a warning message for the ASPs that will lose data. Follow the recovery actions and try to resolve the missing unit situations if possible before continuing. If you cannot make the missing units present and active, then you can still continue, but all data will be lost in the ASPs where units are missing.

  4. Press Enter on the confirmation display to begin to recover the mirrored load source.
    The recovery will use the configuration and remote load source that are found, verified, and displayed on the confirmation display. During recovery, the following actions occur:
    • The system copies the recovered load source onto the load source used for the IPL. All data on the disk , including Licensed Internal Code, system data, and user data, are copied, except for the few pages that uniquely identify each individual disk unit and help distinguish between the two disk units of a mirrored pair. Those pages are built separately for the recovered load source.

      During the recovery the system displays the System Reference Code C6 XX 4205 in the control panel on the system or logical partition. The percent complete, in decimal, is displayed in the third and fourth digits of the reference code (the XX).

    • When the recovery of the load source data is complete, the system performs a directed IPL, using the load source attached to the input/output processor (IOP) that controls the load source, which now contains the recovered data.
  5. If any errors (for example, I/O errors or hardware failures) occur after the copy phase of recovery has begun, you must start the recovery process over again, beginning with the Licensed Internal Code install of the new load source.