queuedefs(4)

The name of the queue, such that a is the default queue for jobs started by at (see at(1)), b is the queue for jobs started by batch (see at(1)), and c is the queue for jobs run from a crontab file (see crontab(1)). Queue names d through y designate user-defined queues.

The maximum number of jobs that can be run simultaneously in that queue. Although any number can be specified here, cron (see cron(1M)) by default limits the number of jobs that can be run on all the queues to 100. This limitation can be removed by setting the variable DISABLE_MAXJOB_LIMIT to 1 in the /etc/default/cron file.

The nice value to give to all jobs in that queue that are not run with a user ID of super-user (see nice(1)). The default value is 2.

The number of seconds to wait before rescheduling a job that was deferred because more than njob jobs were running in that job's queue, or because more than 100 jobs were running in all the queues (see njob above).

The a queue, for at jobs (see at(1)), can have up to 4 jobs running simultaneously, and those jobs will be run with a nice value of 1.

Since no nwait value is given, if a job cannot be run because too many other jobs are running, cron will wait 60 seconds before trying again to run it (see cron(1M)).

The b queue, for batch jobs (see at(1)), can have up to 2 jobs running simultaneously. Those jobs will be run with a nice value of 2. If a job cannot be run because too many other jobs are running, cron will wait 90 seconds before trying again to run it.