NAME

       fence_scsi - I/O fencing agent for SCSI persistent reservations

SYNOPSIS

       fence_scsi [OPTION]...

DESCRIPTION

       fence_scsi  is  an  I/O  fencing agent that uses SCSI-3 persistent reservations to control
       access  to  shared  storage  devices.  These  devices  must  support   SCSI-3   persistent
       reservations (SPC-3 or greater) as well as the "preempt-and-abort" subcommand.

       The  fence_scsi  agent works by having each node in the cluster register a unique key with
       the SCSI devive(s). Once registered, a single node will become the reservation  holder  by
       creating a "write exclusive, registrants only" reservation on the device(s). The result is
       that only registered nodes may write to the device(s). When a  node  failure  occurs,  the
       fence_scsi  agent will remove the key belonging to the failed node from the device(s). The
       failed node will no longer be able to write to the device(s). A manual reboot is required.

       Keys are either be specified manually (see -k option) or generated automatically  (see  -n
       option).  Automatic  key  generation  requires  that  cman  be  running. Keys will then be
       generated using the cluster ID and node ID such that each node has a unique key  that  can
       be determined by any other node in the cluster.

       Devices  can  either  be  specified  manually (see -d option) or discovered automatically.
       Multiple devices can be specified manually by using a comma-separated list. If no  devices
       are  specified,  the  fence_scsi  agent  will  attempt  to discover devices by looking for
       cluster volumes and extracting  the  underlying  devices.  Devices  may  be  device-mapper
       multipath  devices  or  raw  devices.  If  using  a  device-mapper  multipath  device, the
       fence_scsi agent will find the underlying devices (paths) and  created  registrations  for
       each path.

OPTIONS

       -o action
              Fencing  action.  This  value  can be "on", "off", or "status". All actions require
              either a key (see -k option) or node name (see -n option). For "on", the agent will
              attempt to register with the device(s) and create a reservation if none exists. The
              "off" action will attempt to remove a node's key from the device(s).  The  "status"
              action  will  report  whether or not a node's key is currently register with one or
              more of the devices. The default action if "off".

       -d devices
              List of devices to use for current operation. Devices can be  comma-separated  list
              of  raw  device  (eg. /dev/sdc) or device-mapper multipath devices (eg. /dev/dm-3).
              Each device must support SCSI-3 persistent reservations.

       -f logfile
              Log output to file.

       -n nodename
              Name of the node to be fenced. The node name is used to generate the key value used
              for  the  current  operation.  This  option  will  be ignored when used with the -k
              option.

       -k key Key to use for the current operation. This key should be unique to a node. For  the
              "on"  action,  the  key  specifies  the key use to register the local node. For the
              "off" action, this key specifies the key to be removed from the device(s).

       -a     Use the APTPL flag for registrations. This option is only used for the "on" action.

       -h     Print out a help message describing available options, then exit.

       -v     Verbose output.

       -V     Print out a version message, then exit.

STDIN PARAMETERS

       agent = "param"
              This option is used by fence_node(8) and is ignored by fence_scsi.

       nodename = "param"
              Same as -n option.

       action = "param"
              Same as -o option.

       devices = "param"
              Same as -d option.

       logfile = "param"
              Same as -f option

       key = "param"
              Same as -k option.

       aptpl = "1"
              Enable the APTPL flag. Default is 0 (disable).

SEE ALSO

       fence(8), fence_node(8), sg_persist(8), vgs(8), cman_tool(8), cman(5)

                                                                                    fence_scsi(8)