DESTAGE

Read syntax diagramSkip visual syntax diagram DESTAGE SUBSYStem rdevrdev1-rdev2

Authorization

Privilege Class: B

Purpose

Use DESTAGE to force the transfer of modified data in a direct access subsystem cache or nonvolatile storage (NVS) to the backing storage device. This command is valid for cache storage subsystems that support the cache fast write or DASD fast write functions.

The DESTAGE command can be used as part of a shutdown process.

Operands

SUBSYStem
specifies that data for the entire storage subsystem is to be destaged, regardless of which device within the subsystem receives the destage order. This is the default (and only) value.
rdev
rdev1-rdev2
is the real device number, a list of real device numbers, or a range of real device numbers, of devices to which the destage order is to be sent.

Usage Notes

  1. This command may produce delayed responses. For more information, see Delayed Responses to CP Commands.
  2. The DESTAGE command is only valid for cache storage subsystems that support cache fastwrite or DASD fastwrite functions. An error message is generated if the subsystem containing the specified device does not support any of these functions.

Responses

Response 1:

Immediate Response: If the transfer of subsystem data occurs immediately, the following response is issued to the originator of the command. This response is repeated for each unique subsystem identified by the devices specified on the command line.
rdev Subsystem data has been destaged.
rdev
is the real device number of one of the specified devices in a subsystem being destaged.

Response 2:

Delayed Response: If the transfer of subsystem data does not occur immediately, the following response is issued:
Command started:  DESTAGE rdev.
When the transfer of subsystem data completes, the following responses are issued:
rdev Subsystem data has been destaged.
Under certain circumstances, it is possible that a cache storage subsystem will not notify CP when it has completed the transfer of the subsystem data. When this occurs, the appropriate command response cannot be generated. Under these circumstances, command processing is ended after generating the following response:
Command results lost:  DESTAGE rdev.
If errors occur during the asynchronous processing of the command that prevent the successful completion of the command, the following response is displayed:
Command failed:  DESTAGE rdev.
rdev
is the real device number of one of the specified devices in a subsystem being destaged.

Response 3:

Response to System Operator: If the originator of the command is not the system operator, the following response is issued to the system operator when the transfer of subsystem data completes. This response is also repeated for each unique subsystem identified by the devices specified on the command line.
rdev Subsystem data was destaged by userid.
rdev
is the real device number of one of the specified devices in a subsystem being destaged.
userid
is the ID of the user who issued the command.

Messages

  • HCP006E Invalid device type - {rdev|vdev|ldev}
  • HCP009E Invalid range - range
  • HCP021E A real device number was not supplied or it is invalid.
  • HCP026E Operand missing or invalid
  • HCP040E Device {rdev|vdev|ldev} does not exist
  • HCP046E type rdev offline
  • HCP319E Error processing subsystem command - cmd for DASD rdev
  • HCP332E Invalid control unit type - rdev
  • HCP1109E The command command cannot be processed for device rdev because the device is the secondary in a duplex pair.