Removing Printers (and other fun CUPS questions)

[Brian McKee]

On Mon, Jan 11, 2010 at 12:30 PM, Bill Moseley <moseley at hank.org> wrote:
> This is on a 9.10 laptop.  I'm in ipadmin group.
> System->Administration->Printing lists 32 printers.  Some listed printers I
> configured at my home (about 4) and the rest are network printers at the
> office.
> 1) How do I delete the ones I never use?

Some of those printers are 'advertised' by either a server or the
printer themselves.
Those you can't 'delete', but you could choose to stop listening to
the broadcasts.
i.e. in that Printing program under settings uncheck 'show printers
shared by other systems'
or see the 'Listen' directive in cups.conf

> 2) Where are all those printers saved?  Even when I'm not on the office LAN
> I still see the long list of printers.  So, they must be saved some place:
> $ lpinfo -vl | wc -l
> 16
> And: http://localhost:631/printers/   shows only 10 printer.  9 have "Device
> URI: file:/dev/null".

Huh, dunno where they keep it either.  Can you delete them with
 sudo lpadmin -x printerName

> 3) I'm never quite sure how to set up network printers.  Should a machine be
> used as a queue for the network printers and then all print jobs are sent to
> that queue?  Or should each user's workstation find the network printers
> directly and install any required drivers or ppd files?

Depends on the requirements.  I like to send it all to a server, then
have the server forward them to the printer.
I figure the big HD on the server will queue jobs better, and it gives
me one place to start looking for problems etc.

On the other hand, that's a single point of failure, and requires
something that's on and up 24/7

Pick your poison.

> And if using a machine as a queue does that mean clients can send print jobs
> to the queue w/o having to have any specific drivers or ppd files for the
> printers that are connected to the queue machine?

I'm pretty sure you can't do it that way as the client has to render
something the printer can understand, the server doesn't have all the
info.  What you do is have a dumb server that just passes along
everything it gets (a raw queue) and the clients all use real drivers
and settings.

If it's doable the other way I'd love to see some documentation on that.

> 4) And if clients use network printers directly (instead of via some queue
> machine) what happens when the printer's IP address changes?

They have to reinstall/re-set up the printer :-)  Don't let that
happen.   No difference though - the queue machine would be just as
confused if the printer disappeared.

Brian