Explanation
During VARY ONLINE command processing,
the device service exit determined that the device was not allowed
to be online for the specified reason. 
During IPL,
the device number is reported as part of the message text "(dev)"
because there are no additional messages that provide this information.
The number of IEA434I messages is limited to 32 during IPL/NIP. An
IEA444I message will be reported one time during IPL/NIP to indicate
additional IEA434I messages have been suppressed.
In the message
text:
During IPL,
the device number is reported as part of the message text "(dev)"
because there are no additional messages that provide this information.
The number of IEA434I messages is limited to 32 during IPL/NIP. An
IEA444I message will be reported one time during IPL/NIP to indicate
additional IEA434I messages have been suppressed. In the message
text: - dev
- The number of failing DASD device.
- reason
- One of the following reasons:
- PPRC SECONDARY
- SPARE DEVICE
- DUAL COPY SECONDARY
- SW FUNCTION REQUESTED OFFLINE
- devcyls CYL (MAX IS maxcyls)
Where devcyls is the size of the target device in cylinders, and maxcyls is the maximum number of cylinders supported by the installed version of z/OS®. For non-EAV, maxcyls is 65520.
- SSCB TABLE ENTRIES EXCEEDED
- INVALID DSE-1 INVOCATION
- INVALID SENSE-ID DEVICE TYPE
- SSCT ENTRY COUNT INVALID
- RCD DATA IS FOR ALIAS DEVICE
- NUMBER OF SSSCB EXCEEDS MAX
- DUPLEX PAIR NOT CONNECTED
- INVALID CONTROL UNIT MODEL
- A device was attached to a controller that is no longer supported.
- SOFT FENCED
System action
The device remains offline.
Operator response
Device is in a soft fenced state which prevents unintended
access (reads and writes) to the volume. Refer to Device Support
Facilities (ICKDSF) User's Guide and Reference, V1R7 for how
to use the ICKDSF CONTROL with the CLEARFENCE parameter to reset the
soft fencing setting.
System programmer response
Check the system configuration to determine if the device number is correct.
Source
DFSMSdfp
Module
IECDINIT