CUPS Disaster: printer queues going AOL or becoming disfunctional

Wed Jul 9 18:16:57 UTC 2014

At Wed, 9 Jul 2014 12:12:22 -0500 "Ubuntu user technical support,  not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:

> 
> 
> 
> i edited your message to move your response to the bottom. please don't
> top-post.
> 
> 
> On Wed, Jul 9, 2014 at 11:44 AM, Robert Heller <heller at deepsoft.com> wrote:
> 
> > At Wed, 9 Jul 2014 11:26:53 -0500 "Ubuntu user technical support,  not for
> > general discussions" <ubuntu-users at lists.ubuntu.com> wrote:
> >
> >
> > > On Sun, Jun 29, 2014 at 6:04 PM, Robert Heller <heller at deepsoft.com>
> > wrote:
> > >
> > > > Software versions:
> > > >    1) Host Server: CentOS 6.5 (up to date),
> > cups-1.4.2-50.el6_4.5.x86_64
> > > >    2) VM server:   Ubuntu 14.04 (up to date), cups 1.7.2-0ubuntu1
> >  amd64
> > > >    3) Diskless workstations: Ubuntu 14.04 (up to date), cups
> > > > 1.7.2-0ubuntu1 amd64
> > > >
> > > > We have two networked (hard Ethernet, with static IP addresses) Laser
> > > > printers, a HP LaserJet 4200 (old but works great) and a Brother Color
> > > > MFC-9970CDW.
> > > >
> > > > What happened:
> > > >
> > > > I updated the Host Server (standard yum update) and then rebooted it
> > (the
> > > > update brought in a new kernel). And then printer queues became
> > > > 'disfunctional'. Printing a test page resulted in a
> > > > client-error-document-format-not-supported type of error. Deleting and
> > > > re-installing the print queues fixed it. Why did this happen? And why
> > does
> > > > re-installing the print queues fix it? Followup question: is there a
> > way
> > > > to do
> > > > fix this from the command line? It is a royal pain to have to do this
> > with
> > > > the
> > > > web GUI, esp. since it precludes doing it remotely.
> > > >
> > > > Also, just as a side adventure, the Ubuntu VM system decided to (on its
> > > > own!)
> > > > remove the color printer. I have not clue as to  why that happened.  I
> > did
> > > > *uninstall* the pesky cups-browserd package (which is a total disaster
> > for
> > > > a
> > > > server or even fixed desktop machines with fixed hardwired printers).
> > > >
> > >
> > > Since you mention the host and VM CUPS versions that cues me to suggest
> > > first looking for an interaction between them. Think about where the
> > print
> > > jobs are being spooled from. Will users other than Ubuntu VM users need
> > to
> > > print to and manage them? If it makes more sense to support the queues
> > from
> > > the host, then delete all your printer definitions from Ubuntu, create
> > them
> > > in the host CUPS, then have the Ubuntu CUPS definitions point to the VM
> > > printer queues. (There are a few ways to do that; which ways work for you
> > > depend upon several factors.)
> >
> 
> 
> > >
> > > As for the HP printer, after you decide which CUPS server you are going
> > to
> > > support I would suggest you make sure you have all the open-source HP
> > > printer utility packages installed, especially any packages that
> > > specifically mention your printer. I don't know whether the versions
> > > straight from HP have any advantages, but I would first try looking for
> > the
> > > ones the distro provides first. They may or may not have been installed
> > by
> > > default.
> > >
> > > I have a different model Brother printer and its non-open-source software
> > > has to be reinstalled any time the OS gets upgraded. Alternatively, it's
> > > possible your edits to the CUPS config got blown away by a software
> > update
> > > or just a glitch.
> > >
> > > I just looked up your printer at Brother's linux support site -- the url
> > > might be:
> > >
> > >
> > http://support.brother.com/g/s/id/linux/en/index.html?prod=mfc9970cdw_all
> > >
> > > (You may have to go through the Brother site first to get that link to
> > work
> > > because I stripped out my country and language.)
> > >
> > > I suggest you might go through the installation instructions and see if
> > > your edits are still in effect, and also that you have the latest version
> > > of the driver appropriate to the printer and the OS of the CUPS server
> > you
> > > are supporting.
> > >
> >
> > The host (the CentOS 6.5 machine) is the server for everything. The other
> > machines just have 'raw' (postscript?) print queues feeding into the CentOS
> > 6.5 queues).  Since *both* printers are PostScript there should not be
> > much in
> > the way of filters anyway.
> >
> >
> I don't know about the HP, but Brother says that printer supports "PCL6,
> BR-Script3" so that printer is not PostScript.

BR-Script3 is just Brother's 'brand' for PostScript. The printer is in fact a
PostScript (level 3 actually) printer (that *also* does PCL6). The HP printer
is also a PostScript printer (that also does PCL<mumble>). Almost all of
Brother's *laser* printers are PostScript printers. This was something I very
carefully reseached when specificying the printer.

> 
> As I am sure you know, CUPS "automagically" makes all printers PostScript
> compatible, but you also cannot be sure a so-called "raw" queue does no
> transformation.
> 
> I think it would be best to test the queues using processes on CentOS
> before moving to the Ubuntu queues. For example you might create a test.ps
> postscript file you can spool to the printer using the command line
> options. Or, of course, the Test Page feature built into CUPS.
> 
> I suggest you might want to go back and reinstall your Brother
> "cupswrapper" software on CentOS OR confirm you are using an open-source
> compatible PPD that supports your printer's flavor of PCL6.

This is not the problem.  

> 
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> 

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