1fence_scsi(8) System Manager's Manual fence_scsi(8)
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6 fence_scsi - I/O fencing agent for SCSI persistent reservations
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10 fence_scsi [OPTION]...
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14 fence_scsi is an I/O fencing agent that uses SCSI-3 persistent reserva‐
15 tions to control access to shared storage devices. These devices must
16 support SCSI-3 persistent reservations (SPC-3 or greater) as well as
17 the "preempt-and-abort" subcommand.
18 The fence_scsi agent works by having each node in the cluster register
20 a unique key with the SCSI devive(s). Once registered, a single node
21 will become the reservation holder by creating a "write exclusive, reg‐
22 istrants only" reservation on the device(s). The result is that only
23 registered nodes may write to the device(s). When a node failure
24 occurs, the fence_scsi agent will remove the key belonging to the
25 failed node from the device(s). The failed node will no longer be able
26 to write to the device(s). A manual reboot is required.
27 Keys are either be specified manually (see -k option) or generated
29 automatically (see -n option). Automatic key generation requires that
30 cman be running. Keys will then be generated using the cluster ID and
31 node ID such that each node has a unique key that can be determined by
32 any other node in the cluster.
33 Devices can either be specified manually (see -d option) or discovered
35 automatically. Multiple devices can be specified manually by using a
36 comma-separated list. If no devices are specified, the fence_scsi agent
37 will attempt to discover devices by looking for cluster volumes and
38 extracting the underlying devices. Devices may be device-mapper multi‐
39 path devices or raw devices. If using a device-mapper multipath device,
40 the fence_scsi agent will find the underlying devices (paths) and cre‐
41 ated registrations for each path.
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45 -o action
46 Fencing action. This value can be "on", "off", or "status". All
47 actions require either a key (see -k option) or node name (see
48 -n option). For "on", the agent will attempt to register with
49 the device(s) and create a reservation if none exists. The "off"
50 action will attempt to remove a node's key from the device(s).
51 The "status" action will report whether or not a node's key is
52 currently register with one or more of the devices. The default
53 action if "off".
54 -d devices
56 List of devices to use for current operation. Devices can be
57 comma-separated list of raw device (eg. /dev/sdc) or device-map‐
58 per multipath devices (eg. /dev/dm-3). Each device must support
59 SCSI-3 persistent reservations.
60 -f logfile
62 Log output to file.
63 -n nodename
65 Name of the node to be fenced. The node name is used to generate
66 the key value used for the current operation. This option will
67 be ignored when used with the -k option.
68 -k key Key to use for the current operation. This key should be unique
70 to a node. For the "on" action, the key specifies the key use to
71 register the local node. For the "off" action, this key speci‐
72 fies the key to be removed from the device(s).
73 -a Use the APTPL flag for registrations. This option is only used
75 for the "on" action.
76 -h Print out a help message describing available options, then
78 exit.
79 -v Verbose output.
81 -V Print out a version message, then exit.
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86 agent = "param"
87 This option is used by fence_node(8) and is ignored by
88 fence_scsi.
89 nodename = "param"
91 Same as -n option.
92 action = "param"
94 Same as -o option.
95 devices = "param"
97 Same as -d option.
98 logfile = "param"
100 Same as -f option
101 key = "param"
103 Same as -k option.
104 aptpl = "1"
106 Enable the APTPL flag. Default is 0 (disable).
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110 fence(8), fence_node(8), sg_persist(8), vgs(8), cman_tool(8), cman(5)
111 fence_scsi(8)