User`s guide

4-165
Printer, Plotter, and Spooler Subsystem Programming
Editing /etc/qconfig
The /etc/qconfig configuration file can be edited with your text editor of choice. There are
unenforced rules concerning when you can and cannot edit /etc/qconfig without halting or
otherwise corrupting the operation of the spooler.
Modifying /etc/qconfig While Jobs are Processing
/etc/qconfig should never be edited when jobs are processing. This is especially true when
your system has a large number (greater than 25) of printers that are generally pretty busy.
When the qdaemon receives notification from enq that a new Job Description File (JDF)
exists, the qdaemon examines the dates on both /etc/qconfig and /etc/qconfig.bin, the
binary version of /etc/qconfig. If /etc/qconfig is younger than /etc/qconfig.bin, the
qdaemon doesnot accept any new jobs, including the one that caused it to examine the
aforementioned files, until all currently running jobs have finished processing. When the jobs
have finished processing, the qdaemon creates a new version of /etc/qconfig.bin.
If you cause the qdaemon to go into this state while jobs are processing, it is possible for
the spooler to hang. If you modify /etc/qconfig under these conditions, and if any printers
are still generating output, your best option is to leave the system alone and see if it comes
back to life after all the jobs have finished processing. If zero printers are producing output
or the spooler appears to be hung, see ”Cleaning Up and Starting Over” section of Spooler
Troubleshooting, on page 5-14.
Attention: It is worth repeating. Do not cause a change to /etc/qconfig while jobs are
processing. Aside from editing /etc/qconfig and writing a new version of the file to disk
with a text editor, you can cause the same effect by using smit to change a queue
property or a parameter value.
Creating Queue With an Editor
The root user can edit /etc/qconfig and define queues with a text editor. One situation
where this should not be done is when the backend for the spooler queue is piobe. Queues
that use piobe as backend must have an associated virtual printer definition. In this
situation, the root user should use smit to create the queue. Using smit will run several
programs that create the virtual printer definition.