Work with disk unit recovery

Options are available to save and restore disk units, find and assign disk units that are missing from the configuration, replace disk units, reclaim IOA cache storage, and recover the system configuration if it is lost, destroyed, or changed.

Select the Work with Disk Unit Recovery display from the Work with disk units option on the Use Dedicated Service Tools (DST) display.

Save disk unit data

Run this option when the disk unit reference code (URC) indicates that a disk enclosure should be exchanged.

Before removing the disk enclosure and installing a new disk enclosure, save the data from the disk units in the disk enclosure to removable media.

When the system has saved all of the disk unit data to removable media, a menu appears on the display with the status information.

Notes:

This procedure does not save the Licensed Internal Code on the load-source disk unit.
The option is not available for disk units that have device parity protection or mirror protection (with both units in an active state).

Restore disk unit data: This option reads the data (recorded using the Save disk unit option) from the removable medium and writes the data on the disk unit. The data can be restored to a disk unit of the same type or to a different type of disk unit that has the same or larger storage capacity. When all data is restored to the disk unit, a menu appears on the display with the status information. If the replaced disk is load source, the system will perform an IPL to DST from the new disk. For the others, the system will not perform a re-IPL.; For systems with multiple partitions, the partition configuration will have to be restored first.

Replace disk unit: This option is part of the disk unit recovery procedure. The recovery procedure consists in exchanging a configured disk unit for a non-configured unit. Use the Delete ASP data option to clear the system ASP before replacing the disk unit only if the disk is not under mirror or device parity protection. You can make the protection active again after replacing the failed disk by following the Disk Unit Recovery Procedure.

Assign missing units: This option reports any missing units (units that were part of the system during the last IPL that have been disconnected accidentally or configured differently). When you select to assign a unit, the system attempts to find one or more valid non-configured disk units. If no valid non-configured disk units are found, use the Replace disk unit function.

Recover disk configuration: This option recovers the correct system configuration in cases where the load source was damaged and the device configuration table on the installation device was lost.

Disk unit problem recovery procedures: For details about this option, see the main heading Disk unit problem recovery procedures.

Suspend mirrored protection: Select this option when you want to stop mirrored protection for a unit in a mirrored auxiliary storage pool.

Resume mirrored protection: Select this option when you want to restart mirrored protection for a unit in a mirrored auxiliary storage pool.

Copy disk unit data: Copy all the data from a configured disk to a non-configured disk unit. This action can take the place of save disk unit data to tape and a restore disk unit data. After the operation is complete, the target disk unit (the one copied to) takes the place of the original disk unit in the system configuration. The original disk cannot be used in the system configuration without data loss.

Delete disk unit data: Deletes all the data from a non-configured disk unit.
Note: This option is only permitted for non-configured disk units.

Upgrade load-source utility: Migrates the disk unit configuration to a system with new hardware.

Rebuild disk unit data: When a failed disk unit is repaired, use this option to rebuild the data. Use the redundancy feature of device parity protection to rebuild data to a disk unit.
Attention: If there are several disk unit incompatibilities, make certain that the correct units are installed.

Reclaim IOA cache storage: When the IOA cache memory fails and needs to be replaced, you can remove and destroy the damaged data in the IOA cache.; Data can remain in the IOA cache when failures occur. Occasionally, a situation is so severe that the system perceives missing units. This prevents the system from performing an IPL. At other times, a reduction in the amount of usable cache storage occurs. This situation presents itself only as a warning during a manual mode IPL.

Correct device parity protection mismatch: You can accept the situation where configured disk units are expected to have device parity protection enabled but currently have device-parity protection disabled. The configuration no longer expects these disk units to be device parity protected.

Recover unknown load source: You can recover from an unknown load-source error where the mate of the load source in the mirrored pair is missing and the system does not currently recognize the load source.

Recover from start compression failure: Use this option in a recovery from a start compression operation that failed.

Migrate load-source disk unit data: During migration, this option copies data from an original load-source disk unit onto the load-source disk unit of a new system.