CentOS - Feb 2010 - what causes CUPS to dis-enable a printer?

In our computer lab, there are 6 Centos 5.4 workstations. There is an
HP printer with jet direct card. It often works.

But sometimes users come and get me saying the printer is broken, but
it is actually working fine for *most* of the workstations.

On the troubled system, I run system-config-printer and I check the
printer in question (under properties)  and I see the printer has been
disabled. I mean, the box by the word Enabled is empty.

After I manually (use lprm) remove the print jobs, and set the printer
to Enabled, then the print queue will start working again.

I've checked the files in /var/log/cups and there's nothing evident.
error_log has nothing.

We have had the problem during the year (that others have reported in
this list).  When trying to print some pdf files from Evince, the
symptom of the problem is that the pdf files don't print. They seem to
"clog" the printer.  When that happens, I have seen the Enabled box
come unchecked in the printer configurator.  However, the most recent
problems are not associated with the use of Evince.

I would really appreciate some tips about how to bugshoot this problem.

pj

ps. The Cups server is running on the system in question, lpq shows
lots of print jobs waiting.


-- 
Paul E. Johnson
Professor, Political Science
1541 Lilac Lane, Room 504
University of Kansas

Greetings,


On Wed, Feb 10, 2010 at 10:07 AM, Paul Johnson <pauljohn32 at gmail.com>
wrote:
> But sometimes users come and get me saying the printer is broken, but
> it is actually working fine for *most* of the workstations.
>
> On the troubled system, I run system-config-printer and I check the
> printer in question (under properties) ?and I see the printer has been
> disabled. I mean, the box by the word Enabled is empty.
I would strongly suggest using the web interface localhost:631 instead
of system-config-printer.

Regards,

Rajagopal

On Tue, Feb 9, 2010 at 11:37 PM, Paul Johnson <pauljohn32 at gmail.com>
wrote:
> In our computer lab, there are 6 Centos 5.4 workstations. There is an
> HP printer with jet direct card. It often works.
>
> But sometimes users come and get me saying the printer is broken, but
> it is actually working fine for *most* of the workstations.
>
> On the troubled system, I run system-config-printer and I check the
> printer in question (under properties) ?and I see the printer has been
> disabled. I mean, the box by the word Enabled is empty.
>
> After I manually (use lprm) remove the print jobs, and set the printer
> to Enabled, then the print queue will start working again.
>
There is a cups timeout value that might help. Cups will disable a
printer if it doesn't respond after a certain amount of time. If you
add a Timeout value to cupsd.conf you can either disable or set the
timeout higher.

If that doesn't work, you may need to change the loglevel to debug and
watch until it fails.

At Tue, 9 Feb 2010 22:37:28 -0600 CentOS mailing list <centos at
centos.org> wrote:
> 
> In our computer lab, there are 6 Centos 5.4 workstations. There is an
> HP printer with jet direct card. It often works.
> 
> But sometimes users come and get me saying the printer is broken, but
> it is actually working fine for *most* of the workstations.
> 
> On the troubled system, I run system-config-printer and I check the
> printer in question (under properties)  and I see the printer has been
> disabled. I mean, the box by the word Enabled is empty.
> 
> After I manually (use lprm) remove the print jobs, and set the printer
> to Enabled, then the print queue will start working again.
> 
> I've checked the files in /var/log/cups and there's nothing
evident.
> error_log has nothing.
> 
> We have had the problem during the year (that others have reported in
> this list).  When trying to print some pdf files from Evince, the
> symptom of the problem is that the pdf files don't print. They seem to
> "clog" the printer.  When that happens, I have seen the Enabled
box
> come unchecked in the printer configurator.  However, the most recent
> problems are not associated with the use of Evince.
Unless you have a proper print filter for them (on the Linux system!),
PDF files cannot be printed.  
> I would really appreciate some tips about how to bugshoot this problem.
> 
> pj
> 
> ps. The Cups server is running on the system in question, lpq shows
> lots of print jobs waiting.
Wondering if the printer *by itself* can manage handling connections
for a number of workstations and arbitrating jobs.  Maybe you need a
Linux print server to manage the print queue and feed jobs to the
printer one at a time.  It seems like some of the workstations are
getting a refused connection and thinking the printer is 'dead' (and
thus disabling it), when it is merely too busy to respond.  A proper
linux print server would queue up the job and be ready for additional
connections. 
> 
> 
-- 
Robert Heller             -- 978-544-6933
Deepwoods Software        -- Download the Model Railroad System
http://www.deepsoft.com/  -- Binaries for Linux and MS-Windows
heller at deepsoft.com       -- http://www.deepsoft.com/ModelRailroadSystem/

On Tue, Feb 9, 2010 at 6:37 PM, Paul Johnson <pauljohn32 at gmail.com>
wrote:
>
> After I manually (use lprm) remove the print jobs, and set the printer
> to Enabled, then the print queue will start working again.
>
Me too, but even stranger, I do not remove the print jobs and they print
fine as soon as I enable the printer again. This is usually after a power
outage or some temporary problem with the main print server. For some reason
client cups instances get offended by the server and disable the printer.
Then after I fix the real problem, I have to go around re-enabling printers
on all the clients.

Would it (should it) eventually notice that the server is back and re-enable
itself just as automatically as it disabled itself?

Dave



-- 
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Q: Why should this email be 5 sentences or less?
A: http://five.sentenc.es
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On Wed, Feb 10, 2010 at 1:29 PM, Dave <tdbtdb+centos at gmail.com> wrote:
>
> Would it (should it) eventually notice that the server is back and
re-enable
> itself just as automatically as it disabled itself?
>
> Dave
>
I found several people who offer cron scripts to do exactly that!  It
is amazing what you find after you learn the correct thing to Google
for!  Here, the magic words are "lpstat" and "enabled"


http://kbase.redhat.com/faq/docs/DOC-2824

"How do I start (enable) printer queues from a cron job in Red Hat
Enterprise Linux 4?"


-- 
Paul E. Johnson
Professor, Political Science
1541 Lilac Lane, Room 504
University of Kansas