Provided by: dlm-controld_4.2.0-2_amd64 
NAME
dlm.conf - dlm_controld configuration file
SYNOPSIS
/etc/dlm/dlm.conf
DESCRIPTION
The configuration options in dlm.conf mirror the dlm_controld command line options. The
config file additionally allows advanced fencing and lockspace configuration that are not
supported on the command line.
Command line equivalents
If an option is specified on the command line and in the config file, the command line
setting overrides the config file setting. See dlm_controld(8) for descriptions and
dlm_controld -h for defaults.
Format:
setting=value
Example:
log_debug=1
post_join_delay=10
protocol=tcp
Options:
daemon_debug(*)
log_debug(*)
protocol
bind_all
mark
debug_logfile(*)
enable_plock
plock_debug(*)
plock_rate_limit(*)
plock_ownership
drop_resources_time(*)
drop_resources_count(*)
drop_resources_age(*)
post_join_delay(*)
enable_fencing
enable_concurrent_fencing
enable_startup_fencing
enable_quorum_fencing(*)
enable_quorum_lockspace(*)
repeat_failed_fencing(*)
enable_helper
Options with (*) can be reloaded, see Reload config.
Reload config
Some dlm.conf settings can be changed while dlm_controld is running using dlm_tool
reload_config. Edit dlm.conf, adding, removing, commenting or changing values, then run
dlm_tool reload_config to apply the changes in dlm_controld. dlm_tool dump_config will
show the new settings.
Fencing
A fence device definition begins with a device line, followed by a number of connect
lines, one for each node connected to the device.
A blank line separates device definitions.
Devices are used in the order they are listed.
The device key word is followed by a unique dev_name, the agent program to be used, and
args, which are agent arguments specific to the device.
The connect key word is followed by the dev_name of the device section, the node ID of the
connected node in the format node=nodeid and args, which are agent arguments specific to
the node for the given device.
The format of args is key=val on both device and connect lines, each pair separated by a
space, e.g. key1=val1 key2=val2 key3=val3.
Format:
device dev_name agent [args]
connect dev_name node=nodeid [args]
connect dev_name node=nodeid [args]
connect dev_name node=nodeid [args]
Example:
device foo fence_foo ipaddr=1.1.1.1 login=x password=y
connect foo node=1 port=1
connect foo node=2 port=2
connect foo node=3 port=3
device bar fence_bar ipaddr=2.2.2.2 login=x password=y
connect bar node=1 port=1
connect bar node=2 port=2
connect bar node=3 port=3
Parallel devices
Some devices, like dual power or dual path, must all be turned off in parallel for fencing
to succeed. To define multiple devices as being parallel to each other, use the same base
dev_name with different suffixes and a colon separator between base name and suffix.
Format:
device dev_name:1 agent [args]
connect dev_name:1 node=nodeid [args]
connect dev_name:1 node=nodeid [args]
connect dev_name:1 node=nodeid [args]
device dev_name:2 agent [args]
connect dev_name:2 node=nodeid [args]
connect dev_name:2 node=nodeid [args]
connect dev_name:2 node=nodeid [args]
Example:
device foo:1 fence_foo ipaddr=1.1.1.1 login=x password=y
connect foo:1 node=1 port=1
connect foo:2 node=2 port=2
connect foo:3 node=3 port=3
device foo:2 fence_foo ipaddr=5.5.5.5 login=x password=y
connect foo:2 node=1 port=1
connect foo:2 node=2 port=2
connect foo:2 node=3 port=3
Unfencing
A node may sometimes need to "unfence" itself when starting. The unfencing command
reverses the effect of a previous fencing operation against it. An example would be
fencing that disables a port on a SAN switch. A node could use unfencing to re-enable its
switch port when starting up after rebooting. (Care must be taken to ensure it's safe for
a node to unfence itself. A node often needs to be cleanly rebooted before unfencing
itself.)
To specify that a node should unfence itself for a given device, the unfence line is added
after the connect lines.
Format:
device dev_name agent [args]
connect dev_name node=nodeid [args]
connect dev_name node=nodeid [args]
connect dev_name node=nodeid [args]
unfence dev_name
Example:
device foo fence_foo ipaddr=1.1.1.1 login=x password=y
connect foo node=1 port=1
connect foo node=2 port=2
connect foo node=3 port=3
unfence foo
Simple devices
In some cases, a single fence device is used for all nodes, and it requires no node-
specific args. This would typically be a "bridge" fence device in which an agent is
passing a fence request to another subsystem to handle. (Note that a "node=nodeid" arg is
always automatically included in agent args, so a node-specific nodeid is always present
to minimally identify the victim.)
In such a case, a simplified, single-line fence configuration is possible, with format:
fence_all agent [args]
Example:
fence_all dlm_stonith
A fence_all configuration is not compatible with a fence device configuration (above).
Unfencing can optionally be applied with:
fence_all agent [args]
unfence_all
Lockspace configuration
A lockspace definition begins with a lockspace line, followed by a number of master lines.
A blank line separates lockspace definitions.
Format:
lockspace ls_name [ls_args]
master ls_name node=nodeid [node_args]
master ls_name node=nodeid [node_args]
master ls_name node=nodeid [node_args]
Disabling resource directory
Lockspaces usually use a resource directory to keep track of which node is the master of
each resource. The dlm can operate without the resource directory, though, by statically
assigning the master of a resource using a hash of the resource name. To enable, set the
per-lockspace nodir option to 1.
Example:
lockspace foo nodir=1
Lock-server configuration
The nodir setting can be combined with node weights to create a configuration where select
node(s) are the master of all resources/locks. These master nodes can be viewed as "lock
servers" for the other nodes.
Example of nodeid 1 as master of all resources:
lockspace foo nodir=1
master foo node=1
Example of nodeid's 1 and 2 as masters of all resources:
lockspace foo nodir=1
master foo node=1
master foo node=2
Lock management will be partitioned among the available masters. There can be any number
of masters defined. The designated master nodes will master all resources/locks
(according to the resource name hash). When no masters are members of the lockspace, then
the nodes revert to the common fully-distributed configuration. Recovery is faster, with
little disruption, when a non-master node joins/leaves.
There is no special mode in the dlm for this lock server configuration, it's just a
natural consequence of combining the "nodir" option with node weights. When a lockspace
has master nodes defined, the master has a default weight of 1 and all non-master nodes
have weight of 0. An explicit non-zero weight can also be assigned to master nodes, e.g.
lockspace foo nodir=1
master foo node=1 weight=2
master foo node=2 weight=1
In which case node 1 will master 2/3 of the total resources and node 2 will master the
other 1/3.
Node configuration
Node configurations can be set by the node keyword followed of key-value pairs.
Keys:
mark The mark key can be used to set a specific mark value which is then used by the in-
kernel DLM socket creation. This can be used to match for DLM specific packets for e.g.
routing.
Example of setting a per socket value for nodeid 1 and a mark value of 42:
node id=1 mark=42
For local nodes this value doesn't have any effect.
SEE ALSO
dlm_controld(8), dlm_tool(8)