A SVC dump is a core dump initiated by the operating system generally
when a programming exception occurs. SVC dump processing stores data in dump
data sets that you pre-allocate, or that the system allocates automatically
as needed.
Alternatively, you can initiate an SVC dump through the MVS™ console, to
gather diagnostic data for a 'hang' condition, for example. SVC dumps that
you initiate this way are called console dumps.
One example of an abend that could occur is the EC3 abend. WebSphere
® Application
Server for z/OS
® requests
an SVC dump when a controller terminates a servant (region) with an EC3 abend
when timeout conditions occur.
- Your installation can set parmlib options that determine what to dump,
eliminate duplicate dumps, and so on. WebSphere Application Server for z/OS provides
a dump parmlib sample in
SBBOJCL(BBODMCCB)
.
- The standard SDATA expected in a SVC dump:
SDATA=(ALLNUC,CSA,GRSQ,LPA,LSQA,PSA,RGN,SQA,SUM,SWA,TRT),end
- If you cannot find an SVC dump for a specific abend, your installation
might be using Dump analysis and elimination (DAE) to suppress the dump. If
this is the case, you can change DAE to let the dump be taken or set a SLIP
on the specific abend for a particular job name if the timeout is consistently
happening. For further information, see:
- When you initiate a console dump:
- When you want an SVC dump of a servant region, also request a dump of
the servant's controller region.
- Unless you suspect a particular servant region as the source of a problem,
dump the controller region and all of its servant regions.
- If syslog contains a message indicating that the maxspace limit was reached
for this dump, the SVC dump might be a partial one that might not contain
the data you need to diagnose the timeout. This limit means that the data
set used for SVC dump is not large enough, and you have to change the size
to capture a complete dump.
Note: If you are running WebSphere Application
Server for z/OS with
64-bit support, and you specify RGN (region) in the SDATA parameter set, you
will need to allocate a much larger space limit for the SVC dump.
- To view CEEDUMP contents within the SVC dump, use the IPCS verbexit LEDATA,
with the CEEDUMP or NTHREADS options, to format and analyze Language
Environment® control blocks. For additional information, see z/OS Language
Environment Debugging Guide, GA22-756 for instructions for using
IPCS to format and analyze CEEDUMP contents.
See
z/OS MVS Diagnosis:
Tools and Service Aids, GA22-7589 for additional information about
SVC dumps.