CUPS – Eclipse Systems Knowledge Base

How do I delete a printer in Linux?

Warning: As always, please exercise caution when performing system maintenance, especially when initiating processes that can potentially delete data.

Log into the server as root or become root

Delete printer from CUPS
- NOTE: Replace lp1 with the name of the printer being configured (lp1, lp20, etc.)

lpadmin -x lp1

Delete UV driver file:
- NOTE: Replace lp1 with the name of the printer being configured (lp1, lp20, etc.)

rm /usr/spool/uv/lp1.dvr

Delete queue in UV (delete the line starting with LP1):
- NOTE: Replace lp1 with the name of the printer being deleted (lp1, lp20, etc.)

vi /usr/spool/uv/sp.config

Remove the printer hostname (lp1) and IP address from the /etc/hosts file:
```
vi /etc/hosts
```
Refresh the UV spooler:

usa -R

The printer is now can be delete from the Eclipse level

How do I limit the size of CUPS log files?

To reduce the size of the CUPS logs:

Back up the existing configuration settings:

cp /etc/cups/cupsd.conf /etc/cups/cupsd.conf.`date +%Y%m%d.%H%M%S`

Open the /etc/cups/cupsd.conf configuration file in your favorite editor (i.e. vim, nano, Gnome editor, etc.).

Locate the MaxLogSize setting, and change it to a smaller value. For example, 100 MB:

MaxLogSize 100m

Restart the CUPS print service to apply the changes:

service cups restart

Are there any CUPS settings that I can change to keep my Linux print queues from going down?

The default CUPS (Linux print spooler) settings have been shown to be reliable for Eclipse legacy printing at over 100 customer locations. In nearly all instances where print queues are consistently “going down,” a wide area network (WAN) issue has been proven to be the root cause. While working to resolve long-term networking issues, here are a few useful settings that can be adjusted to increase the amount of time allowed by CUPS before disabling a print queue

Timeout

The Timeout directive controls the amount of time CUPS will wait before an active HTTP or IPP request times out. The default timeout is 300 seconds (5 minutes), but this can be increased by modifying the /etc/cups/cupsd.conf configuration file, per the example below (1200 seconds or 20 minutes):

Timeout 1200

Maximum Job Limit

The MaxJobs directive controls the maximum number of jobs that are kept in memory. Once the number of jobs reaches the limit, the oldest completed job is automatically purged from the system to make room for the new one. If all of the known jobs are still pending or active then the new job will be rejected.

In a real-world scenario, if there is a printer down with a very large number of jobs in its queue this setting could cause printing to stop functioning server-wide. For this reason, and to ensure there are no hidden hardware or network issues, it is important to periodically monitor the number of jobs in the print queues (using the lpstat or similar tools).

If you regularly submit more than a few hundred jobs at one time to a print queue, you may wish to increase this setting in /etc/cups/cupsd.conf, taking care not to raise it too high to avoid system crash or spooler filesystem from filling up from an out of control print job.

By default, CUPS limits the number of active jobs at any one time to 500, but this can be increased to a larger value or be disabled entirely by setting the value in /etc/cups/cupsd.conf to 0 per the example below:

MaxJobs 0

Resources

http://www.cups.org/documentation.php/doc-1.3/ref-cupsd-conf.html

How do I manage Linux print queues?

View a step-by-step screencast of this process:

To administer print jobs, first log into the server as root before running any of the following commands.

UniVerse Spooler Commands

To view the status of a UV print queue:

usa -p lp1

To enable a UV print queue:

usa +o -p lp1

To manually start the UV spooler:

cd /u2/uv
bin/usd /usr/spool/uv -t

To cancel print jobs from the UV Spooler:

For a specific job number:

usm -k 12345

For an entire queue:

usm -k -p lp1

Linux (CUPS) Spooler Commands

To view the status of all print queues:

lpc status

To check the status of a single print queue and view a list of pending jobs:

lpc status lp1
lpstat -P lp1
lpstat -plp1

To remove a single print job:

cancel lp1-1234

To remove all print jobs in a queue:

cancel -a lp1

To enable a queue:

cupsenable lp1

To disable a queue:

cupsdisable lp1

To enable all queues:

lpstat -p | grep disabled | awk '{print $2}' | xargs cupsenable

To print a test job:

echo test | lpr -P lp1

To restart/refresh the cups service:

service cups restart

Resources

CUPS Documentation