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
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
Routing code
Descriptor code