/var/log/cups/access_log:localhost - - [04/Jan/2012:13:03:16 -0500] "POST /printers/q401 HTTP/1.1" 200 293053 Print-Job successful-ok
While printing, the job has this message, cause it's taking a few seconds to print. Notice the line prefix W, that means Warning.
/var/log/cups/error_log:W [04/Jan/2012:13:03:16 -0500] [Job 234619] The printer is busy. /var/log/cups/error_log:W [04/Jan/2012:13:03:21 -0500] [Job 234619] The printer is busy. /var/log/cups/error_log:W [04/Jan/2012:13:03:31 -0500] [Job 234619] The printer is busy.
It's done, so logged to page_log
/var/log/cups/page_log:Q401 jong 234619 [04/Jan/2012:13:03:46 -0500] 1 1 - 192.168.4.85 smbprn.00000000 Remote Downlevel Document - -
Tail all those log files and submit one, large, multi-page, slow job to see this happen.
tail -f /var/log/cups/*log & lpr -p Printer123 /tmp/big.txt