Printer Accounting Basics

Printer Accounting Basics

CUPS supports a variety of printer accounting schemes. Aside from the built-in quota and page logging support, there are several third-party solutions that can be found online.

Quota Support

CUPS supports page and size-based quotas for each printer. The quotas are tracked individually for each user, but a single set of limits applies to all users for a particular printer. For example, you can limit every user to 5 pages per day on an expensive printer, but you cannot limit every user except Johnny.

The job-k-limit, job-page-limit, and job-quota-period options determine whether and how quotas are enforced for a printer. The job-quota-period option determines the time interval for quota tracking. The interval is expressed in seconds, so a day is 86,400, a week is 604,800, and a month is 2,592,000 seconds. The job-k-limit option specifies the job size limit in kilobytes. The job-page-limit option specifies the number of pages limit.

For quotas to be enforced, the period and at least one of the limits must be set to a non-zero value. The following options will enable weekly quotas with the given size and page count limits:

/usr/sbin/lpadmin -p printer -o job-quota-period=604800 \
    -o job-k-limit=1024 ENTER
/usr/sbin/lpadmin -p printer -o job-quota-period=604800 \
    -o job-page-limit=100 ENTER

Or, you can combine all three options on the same line.

While there is no way to query the current quota state for a particular user, any application can request a list of jobs for a user and printer that can be used to easily determine that information.

Page Logging

CUPS can log every page that is printed on a system to the page_log file. Page logging must be enabled by setting the PageLogFormat directive in the cupsd.conf file and is only available for drivers that provide page accounting information, typically all PostScript and CUPS raster devices. Raw queues and queues using third-party solutions such as Foomatic generally do not have useful page accounting information available.