ovs-appctl(8) Open vSwitch Manual ovs-appctl(8)
NAME
ovs-appctl - utility for configuring running Open vSwitch daemons
SYNOPSIS
ovs-appctl [--target=target | -t target] command [arg...]
ovs-appctl --help
ovs-appctl --version
DESCRIPTION
Open vSwitch daemons accept certain commands at runtime to control their behavior and query their settings. Every daemon accepts a common
set of commands documented under COMMON COMMANDS below, and ovs-vswitchd in particular accepts a number of additional commands documented
in ovs-vswitchd(8).
The ovs-appctl program provides a simple way to invoke these commands. The command to be sent is specified on ovs-appctl's command line as
non-option arguments. ovs-appctl sends the command and prints the daemon's response on standard output.
In normal use only a single option is accepted:
-t target
--target=target
Tells ovs-appctl which daemon to contact.
If target begins with / it must name a Unix domain socket on which an Open vSwitch daemon is listening for control channel connec-
tions. By default, each daemon listens on a Unix domain socket named /var/run/openvswitch/program.pid.ctl, where program is the
program's name and pid is its process ID. For example, if ovs-vswitchd has PID 123, it would listen on /var/run/open-
vswitch/ovs-vswitchd.123.ctl.
Otherwise, ovs-appctl looks for a pidfile, that is, a file whose contents are the process ID of a running process as a decimal num-
ber, named /var/run/openvswitch/target.pid. (The --pidfile option makes an Open vSwitch daemon create a pidfile.) ovs-appctl reads
the pidfile, then looks for a Unix socket named /var/run/openvswitch/target.pid.ctl, where pid is replaced by the process ID read
from the pidfile, and uses that file as if it had been specified directly as the target.
The default target is ovs-vswitchd.
COMMON COMMANDS
Every Open vSwitch daemon supports a common set of commands, which are documented in this section.
GENERAL COMMANDS
These commands display daemon-specific commands and the running version. Note that these commands are different from the --help and --ver-
sion options that return information about the ovs-appctl utility itself.
help Lists the commands supported by the target.
version
Displays the version and compilation date of the target.
LOGGING COMMANDS
Open vSwitch has several log levels. The highest-severity log level is:
OFF No message is ever logged at this level, so setting a logging facility's log level to OFF disables logging to that facility.
The following log levels, in order of descending severity, are available:
EMER A major failure forced a process to abort.
ERR A high-level operation or a subsystem failed. Attention is warranted.
WARN A low-level operation failed, but higher-level subsystems may be able to recover.
INFO Information that may be useful in retrospect when investigating a problem.
DBG Information useful only to someone with intricate knowledge of the system, or that would commonly cause too-voluminous log output.
Log messages at this level are not logged by default.
Every Open vSwitch daemon supports the following commands for examining and adjusting log levels.
vlog/list
Lists the known logging modules and their current levels.
vlog/set module[:facility[:level]]
Sets the logging level for module in facility to level. The module may be any valid module name (as displayed by the --list option)
or the special name ANY to set the logging levels for all modules. The facility may be syslog or console to set the levels for log-
ging to the system log or to the console, respectively, or ANY to set the logging levels for both facilities. If it is omitted,
facility defaults to ANY. The level must be one of off, emer, err, warn, info, or dbg, designating the minimum severity of a mes-
sage for it to be logged. If it is omitted, level defaults to dbg.
vlog/set PATTERN:facility:pattern
Sets the log pattern for facility to pattern. Each time a message is logged to facility, pattern determines the message's format-
ting. Most characters in pattern are copied literally to the log, but special escapes beginning with % are expanded as follows:
%A The name of the application logging the message, e.g. ovs-vswitchd.
%c The name of the module (as shown by ovs-appctl --list) logging the message.
%d The current date and time in ISO 8601 format (YYYY-MM-DD HH:MM:SS).
%d{format}
The current date and time in the specified format, which takes the same format as the template argument to strftime(3).
%m The message being logged.
%N A serial number for this message within this run of the program, as a decimal number. The first message a program logs has
serial number 1, the second one has serial number 2, and so on.
%n A new-line.
%p The level at which the message is logged, e.g. DBG.
%P The program's process ID (pid), as a decimal number.
%r The number of milliseconds elapsed from the start of the application to the time the message was logged.
%% A literal %.
A few options may appear between the % and the format specifier character, in this order:
- Left justify the escape's expansion within its field width. Right justification is the default.
0 Pad the field to the field width with 0s. Padding with spaces is the default.
width A number specifies the minimum field width. If the escape expands to fewer characters than width then it is padded to fill
the field width. (A field wider than width is not truncated to fit.)
The default pattern for console output is %d{%b %d %H:%M:%S}|%05N|%c|%p|%m; for syslog output, %05N|%c|%p|%m.
vlog/reopen
Causes the daemon to close and reopen its log file. (This is useful after rotating log files, to cause a new log file to be used.)
This has no effect if the target application was not invoked with the --log-file option.
OPTIONS
-h, --help
Prints a brief help message to the console.
-V, --version
Prints version information to the console.
BUGS
The protocol used to speak to Open vSwitch daemons does not contain a quoting mechanism, so command arguments should not generally contain
white space.
SEE ALSO
ovs-appctl can control the following daemons: ovs-vswitchd(8), ovs-controller(8), ovs-brcompatd(8).
Open vSwitch November 2009 ovs-appctl(8)