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RCTL(8)                 FreeBSD System Manager's Manual                RCTL(8)

NAME
     rctl - display and update resource limits database

SYNOPSIS
     rctl [-h] [-n] [filter]
     rctl -a [rule]
     rctl [-h] [-n] -l [filter]
     rctl -r [filter]
     rctl [-h] -u [filter]

DESCRIPTION
     When called without options, the rctl command writes currently defined
     RCTL rules to standard output.

     If a filter argument is specified, only rules matching the filter are
     displayed.  The options are as follows:

     -a rule
             Add rule to the RCTL database.

     -l filter
             Display rules applicable to the process defined by filter.  Note
             that this is different from showing the rules when called without
             any options, as it shows not just the rules with subject equal to
             that of process, but also rules for the user, jail, and login
             class applicable to the process.

     -r filter
             Remove rules matching filter from the RCTL database.

     -u filter
             Display resource usage for a subject (process, user, login class
             or jail) matching the filter.

     -h      "Human-readable" output.  Use unit suffixes: Byte, Kilobyte,
             Megabyte, Gigabyte, Terabyte and Petabyte.

     -n      Display user IDs numerically rather than converting them to a
             user name.

RULE SYNTAX
     Syntax for a rule is subject:subject-id:resource:action=amount/per.

     Subject defines the kind of entity the rule applies to.  It can be either
     process, user, login class, or jail.

     Subject ID identifies the subject.  It can be a process ID, user name,
     numerical user ID, login class name, or jail name.

     Resource identifies the resource the rule controls.

     Action defines what will happen when a process exceeds the allowed
     amount.

     Amount defines how much of the resource a process can use before the
     defined action triggers.

     The per field defines what entity the amount gets accounted for.  For
     example, rule "loginclass:users:vmem:deny=100M/process" means that each
     process of any user belonging to login class "users" may allocate up to
     100MB of virtual memory.  Rule "loginclass:users:vmem:deny=100M/user"
     would mean that for each user belonging to the login class "users", the
     sum of virtual memory allocated by all the processes of that user will
     not exceed 100MB.  Rule "loginclass:users:vmem:deny=100M/loginclass"
     would mean that the sum of virtual memory allocated by all processes of
     all users belonging to that login class will not exceed 100MB.

     Valid rule has all those fields specified, except for the per, which
     defaults to the value of subject.

     A filter is a rule for which one of more fields other than per is left
     empty.  For example, a filter that matches every rule could be written as
     ":::=/", or, in short, ":".  A filter that matches all the login classes
     would be "loginclass:".  A filter that matches all defined rules for
     maxproc resource would be "::maxproc".

RESOURCES
        cputime            CPU time, in seconds
        datasize           data size, in bytes
        stacksize          stack size, in bytes
        coredumpsize       core dump size, in bytes
        memoryuse          resident set size, in bytes
        memorylocked       locked memory, in bytes
        maxproc            number of processes
        openfiles          file descriptor table size
        vmemoryuse         address space limit, in bytes
        pseudoterminals    number of PTYs
        swapuse            swap usage, in bytes
        nthr               number of threads
        msgqqueued         number of queued SysV messages
        msgqsize           SysV message queue size, in bytes
        nmsgq              number of SysV message queues
        nsem               number of SysV semaphores
        nsemop             number of SysV semaphores modified in a single
                           semop(2) call
        nshm               number of SysV shared memory segments
        shmsize            SysV shared memory size, in bytes
        wallclock          wallclock time, in seconds
        pcpu               %CPU, in percents of a single CPU core

ACTIONS
        deny               deny the allocation; not supported for cpu and
                           wallclock
        log                log a warning to the console
        devctl             send notification to devd(8)
        sig*               e.g. sigterm; send a signal to the offending
                           process

     See signal(3) for a list of supported signals.

     Not all actions are supported for all resources.  Attempt to add rule
     with action not supported by a given resource will result in error.

     Note that limiting RSS may kill the machine due to thrashing.

EXIT STATUS
     The rctl utility exits 0 on success, and >0 if an error occurs.

EXAMPLES
     Prevent user "joe" from allocating more than 1GB of virtual memory:
           rctl -a user:joe:vmemoryuse:deny=1g

     Remove all RCTL rules:
           rctl -r :

     Display resource usage information for jail named "www":
           rctl -hu jail:www

     Display all the rules applicable to process with PID 512:
           rctl -l process:512

SEE ALSO
     rctl.conf(5)

HISTORY
     The rctl command appeared in FreeBSD 9.0.

AUTHORS
     The rctl command was written by Edward Tomasz Napierala
     <trasz@FreeBSD.org>.

FreeBSD 11.0-PRERELEASE        December 3, 2012        FreeBSD 11.0-PRERELEASE

NAME | SYNOPSIS | DESCRIPTION | RULE SYNTAX | RESOURCES | ACTIONS | EXIT STATUS | EXAMPLES | SEE ALSO | HISTORY | AUTHORS

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