5. Troubleshooting

5.1. Failing To Connect To Windows Printers

When smbspool, the smbclient utility CUPS uses, fails to connect properly it emits error messages that are humorous but not very helpful. One such message is Unable to connect to SAMBA host: Success. Another sign of connection failures is when documents seem to get stuck on the queue when printing to Windows printers.

View the most recent entries in the CUPS log with the following command:
/usr/bin/tail /var/log/cups/error_log

If you see a message similar to cli_connect() failed... then smbspool could not find the Windows PC you are trying to connect to. Check the spelling of the Windows PC's host name. Check that the Windows PC is turned on and that its network connection is functioning properly. Make sure you can connect to it using smbclient as shown in Section 3.1.

If you see a message similar to SMB tree connect failed: ERRSRV - ERRinvnetname then smbclient connected to the Windows PC but could not connect to the printer you requested. Check the spelling of the shared printer using smbclient as shown in Section 3.1.

5.2. Other Failures

Other failures include being unable to print to a local printer and having your print jobs disappear from the queue without being printed. You may also see vague error messages such as Child process 2384 exited with status 32.

Increase CUPS' logging level to "debug" to see more messages about what happened before the print job failed.

  1. Open the main CUPS configuration file /etc/cups/cupsd.conf in a text editor.

  2. Change the line that reads "LogLevel warn" to "LogLevel debug".

  3. Save the configuration file and exit the text editor.

  4. Restart the CUPS server with the command:
    /etc/init.d/cupsys restart
    

You can follow the CUPS log with the following command:
/usr/bin/tail -f /var/log/cups/error_log

You should see a line that reads Scheduler shutting down due to SIGTERM. This indicates that the CUPS server was stopped successfully.

Send your print job again and watch for useful debug messages that appear. One example of a useful debug message is GNU Ghostscript 7.05: Can't start ijs server 'hpijs'. In this case the solution is to install the "hpijs" package.

If you cannot determine the cause of the failure, do an Internet search for key terms in error messages you see; it is likely that someone has solved your problem before. You may also try upgrading the packages listed in Section 2.2 to their latest versions.