1fence_scsi(8) System Manager's Manual fence_scsi(8)
2
6 fence_scsi - I/O fencing agent for SCSI persistent reservations
7
10 fence_scsi [OPTION]...
11
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. In the cluster
27 environment unfence action should be configured also.
28 Keys are either be specified manually (see -k option) or generated
30 automatically (see -n option). Automatic key generation requires that
31 cman be running. Keys will then be generated using the cluster ID and
32 node ID such that each node has a unique key that can be determined by
33 any other node in the cluster.
34 Devices can either be specified manually (see -d option) or discovered
36 automatically. Multiple devices can be specified manually by using a
37 comma-separated list. If no devices are specified, the fence_scsi agent
38 will attempt to discover devices by looking for cluster volumes and
39 extracting the underlying devices. Devices may be device-mapper multi‐
40 path devices or raw devices. If using a device-mapper multipath device,
41 the fence_scsi agent will find the underlying devices (paths) and cre‐
42 ated registrations for each path.
43
46 -o action
47 Fencing action. This value can be "on", "off", "status", or
48 "metadata". The "on", "off", and "status" actions require either
49 a key (see -k option) or node name (see -n option). For "on",
50 the agent will attempt to register with the device(s) and create
51 a reservation if none exists. The "off" action will attempt to
52 remove a node's key from the device(s). The "status" action will
53 report whether or not a node's key is currently register with
54 one or more of the devices. The "metadata" action will display
55 the XML metadata. The default action if "off".
56 -d devices
58 List of devices to use for current operation. Devices can be
59 comma-separated list of raw device (eg. /dev/sdc) or device-map‐
60 per multipath devices (eg. /dev/dm-3). Each device must support
61 SCSI-3 persistent reservations.
62 -f logfile
64 Log output to file.
65 -n nodename
67 Name of the node to be fenced. The node name is used to generate
68 the key value used for the current operation. This option will
69 be ignored when used with the -k option.
70 -k key Key to use for the current operation. This key should be unique
72 to a node. For the "on" action, the key specifies the key use to
73 register the local node. For the "off" action, this key speci‐
74 fies the key to be removed from the device(s).
75 -H delay
77 Wait X seconds before fencing is started (Default Value: 0)
78 -a Use the APTPL flag for registrations. This option is only used
81 for the "on" action.
82 -h Print out a help message describing available options, then
84 exit.
85 -v Verbose output.
87 -V Print out a version message, then exit.
89
92 agent = "param"
93 This option is used by fence_node(8) and is ignored by
94 fence_scsi.
95 nodename = "param"
97 Same as -n option.
98 action = "param"
100 Same as -o option.
101 devices = "param"
103 Same as -d option.
104 logfile = "param"
106 Same as -f option
107 key = "param"
109 Same as -k option.
110 delay = "param"
112 Same as -H option.
113 aptpl = "1"
115 Enable the APTPL flag. Default is 0 (disable).
116
119 fence(8), fence_node(8), sg_persist(8), vgs(8), cman_tool(8), cman(5)
120 fence_scsi(8)