IOS427A
dev, chp, xxxxxx FAILURE, REPLY: WITH UR BOX OR NOOP.

Explanation

During I/O processing, a device failed.

In the message text:
dev
The device number.
chp
The identifier (CHPID) of the channel path through which the system was accessing the device. If the system could not determine the channel path, asterisks appear in this field.
xxxxxx
One of the following:
CHANNEL PATH
The failure occurred in the channel path.
CONTROL UNIT
This value appears for any failure other than a failing channel path. An inoperative control unit, a missing interrupt, or no operational paths are possible failures.

System action

The system holds all requests to the device until the operator responds to this message.

If CONTROL UNIT is in the message text, the system does not proceed with unconditional reserve processing because ownership of the device is unknown. Depending on the operator reply, the system does the following:
Operator Reply
System Action
UR
The system does the following:
  • For dynamic pathing devices, if the device is reserved to another stopped system, the system issues message IOS430I. The system that is holding the reserve detects any remaining hardware problem and performs recovery.
  • If the UR command is successful, the system issues message IOS428I
  • If the UR command is unsuccessful, the system issues messages IOS429I and IOS104I.
  • The system allows any previously held requests to start.
BOX
The system does the following:
  • Concludes any previously held I/O requests in permanent error
  • Concludes any new I/O requests in permanent error
  • Prevents any new allocations to the device
  • Marks the device pending offline, if the device is online
  • Issues messages IOS429I and IOS1051
  • Takes the device offline if the device is no longer allocated to a job
NOOP
If the failure recurs, the system issues message IOS427A again.

Operator response

Do one of the following:
  • Verify that the device is not reserved to another system
  • Stop all affected systems or vary the device offline on all sharing systems.
  • Reply NOOP to allow previously held requests to start.
  • Reply UR to recover access to device dev. But first, to prevent the loss of data set integrity, prevent normal activity to the device with one of the following methods:
    • Enter the IOACTION STOP command for the device on each system that shares device dev. Wait for a successful response from the command before proceeding.
    • Cancel all jobs allocated to the device on each of the sharing systems and vary device dev offline on all sharing systems.
    • If the device is a dynamic pathing device, then stop the sharing system to stop I/O activity to the device.
      Note: Stopping sharing processors to ensure data integrity during recovery of non-dynamic pathing devices will not work.

    Then enter UR to recover access to device dev through an alternate channel path. If no alternate path exists or the UR command fails on all alternate paths, the command is entered on the failing channel path.

  • Reply BOX to box device dev.
  • If the error persists, take the path or the device offline. Contact hardware support.

When this message is issued before the MVS™ Console becomes active, IT IS EXTREMELY IMPORTANT to respond promptly. This message is issued as a synchronous WTOR during early IPL processing, which will prevent the system from updating its status on the sysplex couple data set. This, in turn, could lead to Sysplex Failure Management (SFM) deciding that the system is not responding normally, and removing it from the sysplex.

Note: If you do not respond within the maximum response time of two minutes, the master console might not accept the reply. Go to the system or service console and respond from there.

Source

Input/output supervisor (IOS)

Module

IOSVURDT

Routing code

1,4,10

Descriptor code

2

Parent topic: IOS messages