NAME

       dlm.conf - dlm_controld configuration file

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:

       key=val

       Example:

       log_debug=1
       post_join_delay=10
       protocol=tcp

       Options:

       daemon_debug
       log_debug
       protocol
       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

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 node=1

       Example of nodeid's 1 and 2 as masters of all resources:

       lockspace foo nodir=1
       master node=1
       master 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 node=1 weight=2
       master 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.

SEE ALSO

       dlm_controld(8), dlm_tool(8)