NAME¶
ovs-vswitchd - Open vSwitch daemon
SYNOPSIS¶
ovs-vswitchd [
database]
DESCRIPTION¶
A daemon that manages and controls any number of Open vSwitch switches on the
local machine.
The
database argument specifies how
ovs-vswitchd connects to
ovsdb-server. The default is
unix:/var/run/openvswitch/db.sock.
The following forms are accepted:
- ssl:ip:port
- The specified SSL port on the host at the given
ip, which must be expressed as an IP address (not a DNS name). The
--private-key, --certificate, and --ca-cert options
are mandatory when this form is used.
- tcp:ip:port
- Connect to the given TCP port on ip.
- unix:file
- Connect to the Unix domain server socket named
file.
- pssl:port[:ip]
- Listen on the given SSL port for a connection. By
default, ovs-vswitchd listens for connections to any local IP
address, but specifying ip limits connections to those from the
given ip. The --private-key, --certificate, and
--ca-cert options are mandatory when this form is used.
- ptcp:port[:ip]
- Listen on the given TCP port for a connection. By
default, ovs-vswitchd listens for connections to any local IP
address, but ip may be specified to listen only for connections to
the given ip.
- punix:file
- Listen on the Unix domain server socket named file
for a connection.
ovs-vswitchd retrieves its configuration from
database at startup.
It sets up Open vSwitch datapaths and then operates switching across each
bridge described in its configuration files. As the database changes,
ovs-vswitchd automatically updates its configuration to match.
Upon receipt of a SIGHUP signal,
ovs-vswitchd reopens its log file, if
one was specified on the command line.
ovs-vswitchd switches may be configured with any of the following
features:
- •
- L2 switching with MAC learning.
- •
- NIC bonding with automatic fail-over and source MAC-based
TX load balancing ("SLB").
- •
- 802.1Q VLAN support.
- •
- Port mirroring, with optional VLAN tagging.
- •
- NetFlow v5 flow logging.
- •
- sFlow(R) monitoring.
- •
- Connectivity to an external OpenFlow controller, such as
NOX.
Only a single instance of
ovs-vswitchd is intended to run at a time. A
single
ovs-vswitchd can manage any number of switch instances, up to
the maximum number of supported Open vSwitch datapaths.
ovs-vswitchd does all the necessary management of Open vSwitch datapaths
itself. Thus, external tools, such
ovs-dpctl(8), are not needed for
managing datapaths in conjunction with
ovs-vswitchd, and their use to
modify datapaths when
ovs-vswitchd is running can interfere with its
operation. (
ovs-dpctl may still be useful for diagnostics.)
An Open vSwitch datapath kernel module must be loaded for
ovs-vswitchd to
be useful. Please refer to the
INSTALL.Linux file included in the Open
vSwitch distribution for instructions on how to build and load the Open
vSwitch kernel module.
OPTIONS¶
- --mlockall
- Causes ovs-vswitchd to call the mlockall()
function, to attempt to lock all of its process memory into physical RAM,
preventing the kernel from paging any of its memory to disk. This helps to
avoid networking interruptions due to system memory pressure.
- Some systems do not support mlockall() at all, and
other systems only allow privileged users, such as the superuser, to use
it. ovs-vswitchd emits a log message if mlockall() is
unavailable or unsuccessful.
- --pidfile[=pidfile]
- Causes a file (by default, ovs-vswitchd.pid) to be
created indicating the PID of the running process. If the pidfile
argument is not specified, or if it does not begin with /, then it
is created in /var/run/openvswitch.
- If --pidfile is not specified, no pidfile is
created.
- --overwrite-pidfile
- By default, when --pidfile is specified and the
specified pidfile already exists and is locked by a running process,
ovs-vswitchd refuses to start. Specify --overwrite-pidfile
to cause it to instead overwrite the pidfile.
- When --pidfile is not specified, this option has no
effect.
- --detach
- Causes ovs-vswitchd to detach itself from the
foreground session and run as a background process. ovs-vswitchd
detaches only after it has connected to the database, retrieved the
initial configuration, and set up that configuration.
- --monitor
- Creates an additional process to monitor the
ovs-vswitchd daemon. If the daemon dies due to a signal that
indicates a programming error (e.g. SIGSEGV, SIGABRT), then
the monitor process starts a new copy of it. If the daemon die or exits
for another reason, the monitor process exits.
- This option is normally used with --detach, but it
also functions without it.
- --no-chdir
- By default, when --detach is specified,
ovs-vswitchd changes its current working directory to the root
directory after it detaches. Otherwise, invoking ovs-vswitchd from
a carelessly chosen directory would prevent the administrator from
unmounting the file system that holds that directory.
- Specifying --no-chdir suppresses this behavior,
preventing ovs-vswitchd from changing its current working
directory. This may be useful for collecting core files, since it is
common behavior to write core dumps into the current working directory and
the root directory is not a good directory to use.
- This option has no effect when --detach is not
specified.
Public Key Infrastructure Options¶
- -p privkey.pem
-
- --private-key=privkey.pem
- Specifies a PEM file containing the private key used as
ovs-vswitchd's identity for outgoing SSL connections.
- -c cert.pem
-
- --certificate=cert.pem
- Specifies a PEM file containing a certificate that
certifies the private key specified on -p or --private-key
to be trustworthy. The certificate must be signed by the certificate
authority (CA) that the peer in SSL connections will use to verify
it.
- -C cacert.pem
-
- --ca-cert=cacert.pem
- Specifies a PEM file containing the CA certificate that
ovs-vswitchd should use to verify certificates presented to it by
SSL peers. (This may be the same certificate that SSL peers use to verify
the certificate specified on -c or --certificate, or it may
be a different one, depending on the PKI design in use.)
- -C none
-
- --ca-cert=none
- Disables verification of certificates presented by SSL
peers. This introduces a security risk, because it means that certificates
cannot be verified to be those of known trusted hosts.
- --bootstrap-ca-cert=cacert.pem
- When cacert.pem exists, this option has the same
effect as -C or --ca-cert. If it does not exist, then
ovs-vswitchd will attempt to obtain the CA certificate from the SSL
peer on its first SSL connection and save it to the named PEM file. If it
is successful, it will immediately drop the connection and reconnect, and
from then on all SSL connections must be authenticated by a certificate
signed by the CA certificate thus obtained.
- This option exposes the SSL connection to a
man-in-the-middle attack obtaining the initial CA certificate,
but it may be useful for bootstrapping.
- This option is only useful if the SSL peer sends its CA
certificate as part of the SSL certificate chain. The SSL protocol does
not require the server to send the CA certificate, but
ovs-controller(8) can be configured to do so with the
--peer-ca-cert option.
- This option is mutually exclusive with -C and
--ca-cert.
- -vmodule[:facility[:level]],
--verbose=module[:facility[:level]]
- Sets the logging level for module in facility
to level:
- •
- module may be any valid module name (as displayed by
the --list action on ovs-appctl(8)), or the special name
ANY to set the logging levels for all modules.
- •
- facility may be syslog, console, or
file to set the levels for logging to the system log, the console,
or a file respectively, or ANY to set the logging levels for both
facilities. If it is omitted, facility defaults to ANY.
- Regardless of the log levels set for file, logging
to a file will not take place unless --log-file is also specified
(see below).
- •
- level must be one of off, emer,
err, warn, info, or dbg, designating the
minimum severity of a message for it to be logged. If it is omitted,
level defaults to dbg. See ovs-appctl(8) for a
definition of each log level.
- -v, --verbose
- Sets the maximum logging verbosity level, equivalent to
--verbose=ANY:ANY:dbg.
- -vPATTERN:facility:pattern,
--verbose=PATTERN: facility:pattern
- Sets the log pattern for facility to pattern.
Refer to ovs-appctl(8) for a description of the valid syntax for
pattern.
- --log-file[=file]
- Enables logging to a file. If file is specified,
then it is used as the exact name for the log file. The default log file
name used if file is omitted is
/var/log/openvswitch/ovs-vswitchd.log.
- -h, --help
- Prints a brief help message to the console.
- -V, --version
- Prints version information to the console.
- --check-leaks=file
- Logs information about memory allocation and deallocation
to file, to allow for debugging memory leaks in
ovs-vswitchd. This option slows down ovs-vswitchd
considerably, so it should only be used when a memory leak is suspected.
Use the ovs-parse-leaks script to interpret the leak file.
- --leak-limit=size
- Limits size of the leak file as specified by
--check-leaks to size bytes. Finding leaks sometimes
requires allowing the leak file to grow very large, up to 1GB. By default,
files are limited to 10MB.
RUNTIME MANAGEMENT COMMANDS¶
ovs-appctl(8) can send commands to a running
ovs-vswitchd process.
The currently supported commands are described below. The command descriptions
assume an understanding of how to configure Open vSwitch.
GENERAL COMMANDS¶
- exit
- Causes ovs-vswitchd to gracefully terminate.
- coverage/log
- Logs coverage counters at level warn.
- qos/show interface
- Queries the kernel for Quality of Service configuration and
statistics associated with the given interface.
- cfm/show [interface]
- Displays detailed information about Connectivity Fault
Management configured on interface. If interface is not
specified, then displays detailed information about all interfaces with
CFM enabled.
BRIDGE COMMANDS¶
These commands manage bridges.
- fdb/flush [bridge]
- Flushes bridge MAC address learning table, or all
learning tables if no bridge is given.
- fdb/show bridge
- Lists each MAC address/VLAN pair learned by the specified
bridge, along with the port on which it was learned and the age of
the entry, in seconds.
- bridge/reconnect [bridge]
- Makes bridge drop all of its OpenFlow controller
connections and reconnect. If bridge is not specified, then all
bridges drop their controller connections and reconnect.
- This command might be useful for debugging OpenFlow
controller issues.
- bridge/dump-flows bridge
- Lists all flows in bridge, including those normally
hidden to commands such as ovs-ofctl dump-flows. Flows set up by
mechanisms such as in-band control and fail-open are hidden from the
controller since it is not allowed to modify or override them.
BOND COMMANDS¶
These commands manage bonded ports on an Open vSwitch's bridges. To understand
some of these commands, it is important to understand a detail of the bonding
implementation called ``source load balancing'' (SLB). Instead of directly
assigning Ethernet source addresses to slaves, the bonding implementation
computes a function that maps an 48-bit Ethernet source addresses into an
8-bit value (a ``MAC hash'' value). All of the Ethernet addresses that map to
a single 8-bit value are then assigned to a single slave.
- bond/list
- Lists all of the bonds, and their slaves, on each
bridge.
- bond/show port
- Lists all of the bond-specific information about the given
bonded port: updelay, downdelay, time until the next rebalance.
Also lists information about each slave: whether it is enabled or
disabled, the time to completion of an updelay or downdelay if one is in
progress, whether it is the active slave, the MAC hashes assigned to the
slave, and the MAC learning table entries that hash to each MAC. Any LACP
information related to this bond may be found using the lacp/show
command.
- bond/migrate port hash
slave
- Only valid for SLB bonds. Assigns a given MAC hash to a new
slave. port specifies the bond port, hash the MAC hash to be
migrated (as a decimal number between 0 and 255), and slave the new
slave to be assigned.
- The reassignment is not permanent: rebalancing or fail-over
will cause the MAC hash to be shifted to a new slave in the usual
manner.
- A MAC hash cannot be migrated to a disabled slave.
- bond/set-active-slave port slave
- Sets slave as the active slave on port.
slave must currently be enabled.
- The setting is not permanent: a new active slave will be
selected if slave becomes disabled.
- bond/enable-slave port slave
-
- bond/disable-slave port slave
- Enables (or disables) slave on the given bond
port, skipping any updelay (or downdelay).
- This setting is not permanent: it persists only until the
carrier status of slave changes.
- bond/hash mac [vlan]
[basis]
- Returns the hash value which would be used for mac
with vlan and basis if specified.
- lacp/show [port]
- Lists all of the LACP related information about the given
port: active or passive, aggregation key, system id, and system
priority. Also lists information about each slave: whether it is enabled
or disabled, whether it is attached or detached, port id and priority,
actor information, and partner information. If port is not
specified, then displays detailed information about all interfaces with
CFM enabled.
OFPROTO COMMANDS¶
These commands manage the core OpenFlow switch implementation (called
ofproto).
- ofproto/list
- Lists the names of the running ofproto instances. These are
the names that may be used on ofproto/trace.
- ofproto/trace switch priority tun_id in_port
packet
-
- ofproto/trace switch odp_flow
-generate
- Traces the path of an imaginary packet through
switch. Both forms require switch, the switch on which the
packet arrived (one of those listed by ofproto/list). The first
form specifies a packet's contents explicitly:
- priority
- Packet QoS priority. Use 0 if QoS is not setup.
- tun_id
- The tunnel ID on which the packet arrived. Use 0 if
the packet did not arrive through a tunnel.
- in_port
- The OpenFlow port on which the packet arrived. Use
65534 if the packet arrived on OFPP_LOCAL, the local
port.
- packet
- A sequence of hex digits specifying the packet's contents.
An Ethernet frame is at least 14 bytes long, so there must be at least 28
hex digits. Obviously, it is inconvenient to type in the hex digits by
hand, so the ovs-pcap(1) and ovs-tcpundump(1) utilities
provide easier ways.
- The second form specifies the packet's contents
implicitly:
- odp_flow
- A flow in the form printed by ovs-dpctl(8)'s
dump-flows command. This is not an OpenFlow flow: besides other
differences, it never contains wildcards. ovs-vswitchd generates an
arbitrary packet that has the specified odp_flow.
- ovs-vswitchd will respond with extensive information
on how the packet would be handled if it were to be received. The packet
will not actually be sent, but side effects such as MAC learning will
occur.
- ofproto/trace switch odp_flow
- Traces the path of a packet in an imaginary flow through
switch. The arguments are:
- switch
- The switch on which the packet arrived (one of those listed
by ofproto/list).
- odp_flow
- A flow in the form printed by ovs-dpctl(8)'s
dump-flows command. This is not an OpenFlow flow: besides other
differences, it never contains wildcards.
- ovs-vswitchd will respond with extensive information
on how a packet in odp_flow would be handled if it were received by
switch. No packet will actually be sent. Some side effects may
occur, but MAC learning in particular will not.
- This form of ofproto/trace cannot determine the
complete set of datapath actions in some corner cases. If the results say
that this is the case, rerun ofproto/trace supplying a packet in
the flow to get complete results.
VLOG COMMANDS¶
These commands manage
ovs-vswitchd's logging settings.
- vlog/set
module[:facility[: level]]
- Sets the logging level for module in facility
to level:
- •
- module may be any valid module name (as displayed by
the --list action on ovs-appctl(8)), or the special name
ANY to set the logging levels for all modules.
- •
- facility may be syslog, console, or
file to set the levels for logging to the system log, the console,
or a file respectively, or ANY to set the logging levels for both
facilities. If it is omitted, facility defaults to ANY.
- The log level for the file facility has no effect
unless ovs-vswitchd was invoked with the --log-file
option.
- •
- level must be one of off, emer,
err, warn, info, or dbg, designating the
minimum severity of a message 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.
Refer to ovs-appctl(8) for a description of the valid syntax for
pattern.
- vlog/list
- Lists the supported logging modules and their current
levels.
- vlog/reopen
- Causes ovs-vswitchd 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 unless ovs-vswitchd was invoked
with the --log-file option.
STRESS OPTION COMMANDS¶
These command manage stress options, which allow developers testing Open vSwitch
to trigger behavior that otherwise would occur only in corner cases.
Developers and testers can thereby more easily discover bugs that would
otherwise manifest only rarely or nondeterministically. Stress options may
cause surprising behavior even when they do not actually reveal bugs, so they
should only be enabled as part of testing Open vSwitch.
- stress/enable
-
- stress/disable
- All stress options are disabled by default. Use
stress/enable to enable stress options and stress/disable to
disable them.
- stress/list
- Lists and describes the available stress options and their
settings in tabular form. The columns in the table are:
- NAME
- A single-word identifier for the option, used to identify
stress options to stress/set.
- DESCRIPTION
- A description for a person unfamiliar with the detailed
internals of the code what behavior the option affects.
- PERIOD
- Currently configured trigger period. If the stress option
is disabled, this is disabled. Otherwise this is a number giving
the number of occurrences of the event between activations of the stress
option triggers.
- MODE
- If the stress option is disabled, this is n/a.
Otherwise it is periodic if the stress option triggers after
exactly the period, or random if it triggers randomly but on
average after the number of occurrences specified by the period.
- COUNTER
- If the stress option is disabled, this is n/a.
Otherwise it is the number of occurrences of the event before the next
time the stress option triggers.
- HITS
- The number of times that this stress option has triggered
since this program started.
- RECOMMENDED
- A suggested period for a person unfamiliar with the
internals. It should put reasonable stress on the system without crippling
it.
- MINIMUM
-
- MAXIMUM
- Minimum and maximum values allowed for the period.
- DEFAULT
- The default period, used when stress options have been
enabled (with stress/enable) but this particular stress option has
not been specifically configured (with stress/set). It is
disabled if the option is disabled by default. It is nonzero for
options that can be left on at low levels without noticeable impact to the
end user.
- stress/set option period
[random| periodic]
- Sets the period at which stress option triggers to
period. A period of 0 disables option. Specify
random to make the option trigger randomly with an average period
of period, or periodic to trigger exactly every
period events; the latter is the default.
- If stress options have not been enabled with
stress/enable, this command has no effect.
SEE ALSO¶
ovs-appctl(8),
ovs-brcompatd(8),
ovsdb-server(1),
INSTALL.Linux in the Open vSwitch distribution.