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2FENCE_AGENT(8)              System Manager's Manual             FENCE_AGENT(8)
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NAME

7       fence_scsi - Fence agent for SCSI persistent reservation
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DESCRIPTION

10       fence_scsi is an I/O fencing agent that uses SCSI-3 persistent reserva‐
11       tions to control access to shared storage devices. These  devices  must
12       support  SCSI-3  persistent  reservations (SPC-3 or greater) as well as
13       the "preempt-and-abort" subcommand.  The fence_scsi agent works by hav‐
14       ing  each  node  in  the  cluster  register  a unique key with the SCSI
15       device(s). Reservation key is generated from  "node  id"  (default)  or
16       from  "node  name  hash" (RECOMMENDED) by adjusting "key_value" option.
17       Using hash is recommended to prevent issues when  removing  nodes  from
18       cluster  without  full  cluster restart. Once registered, a single node
19       will become the reservation holder by creating a "write exclusive, reg‐
20       istrants  only"  reservation  on the device(s). The result is that only
21       registered nodes may write  to  the  device(s).  When  a  node  failure
22       occurs,  the  fence_scsi  agent  will  remove  the key belonging to the
23       failed node from the device(s). The failed node will no longer be  able
24       to write to the device(s). A manual reboot is required.
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26       When  used  as  a  watchdog  device you can define e.g. retry=1, retry-
27       sleep=2 and verbose=yes parameters  in  /etc/sysconfig/stonith  if  you
28       have issues with it failing.
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30       fence_scsi  accepts  options on the command line as well as from stdin.
31       Fenced  sends  parameters  through  stdin  when  it  execs  the  agent.
32       fence_scsi  can  be  run  by itself with command line options.  This is
33       useful for testing and for turning outlets on or off from scripts.
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35       Vendor URL:
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PARAMETERS

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40       -o, --action=[action]
41              Fencing action (Default Value: off)
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43       -a, --aptpl
44              Use the APTPL flag for registrations. This option is  only  used
45              for the 'on' action.
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47       -d, --devices=[devices]
48              List  of  devices  to  use for current operation. Devices can be
49              comma-separated list of raw devices (eg. /dev/sdc). Each  device
50              must support SCSI-3 persistent reservations.
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52       -k, --key=[key]
53              Key  to use for the current operation. This key should be unique
54              to a node. For the "on" action, the key specifies the key use to
55              register  the  local node. For the "off" action, this key speci‐
56              fies the key to be removed from the device(s).
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58       -n, --plug=[nodename]
59              Name of the node to be fenced. The node name is used to generate
60              the  key  value used for the current operation. This option will
61              be ignored when used with  the  -k  option.  This  parameter  is
62              always required.
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64       --readonly
65              Open DEVICE read-only.
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67       -f, --logfile
68              Log output (stdout and stderr) to file
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70       -q, --quiet
71              Disable logging to stderr. Does not affect --verbose or --debug-
72              file or logging to syslog.
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74       -v, --verbose
75              Verbose mode. Multiple -v flags can be stacked  on  the  command
76              line (e.g., -vvv) to increase verbosity.
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78       --verbose-level
79              Level  of  debugging detail in output. Defaults to the number of
80              --verbose flags specified on the command line, or to 1  if  ver‐
81              bose=1  in  a  stonith  device  configuration  (i.e., on stdin).
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83
84       -D, --debug-file=[debugfile]
85              Write debug information to given file
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87       -V, --version
88              Display version information and exit
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90       -h, --help
91              Display help and exit
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93       --delay=[seconds]
94              Wait X seconds before fencing  is  started  (Default  Value:  0)
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96
97       --disable-timeout=[true/false]
98              Disable  timeout (true/false) (default: true when run from Pace‐
99              maker 2.0+)
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101       --login-timeout=[seconds]
102              Wait X seconds for cmd prompt after  login  (Default  Value:  5)
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105       --power-timeout=[seconds]
106              Test  X  seconds  for status change after ON/OFF (Default Value:
107              20)
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109       --power-wait=[seconds]
110              Wait X seconds after issuing ON/OFF (Default Value: 0)
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112       --shell-timeout=[seconds]
113              Wait X seconds for cmd prompt  after  issuing  command  (Default
114              Value: 3)
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116       --retry-on=[attempts]
117              Count of attempts to retry power on (Default Value: 1)
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119       --corosync-cmap-path=[path]
120              Path     to     corosync-cmapctl    binary    (Default    Value:
121              /usr/sbin/corosync-cmapctl)
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123       --key-value=<id|hash>
124              Method used to generate the SCSI key. "id"  (default)  uses  the
125              positional  ID  from "corosync-cmactl nodelist" output which can
126              get inconsistent when nodes are  removed  from  cluster  without
127              full  cluster restart. "hash" uses part of hash made out of node
128              names which is not affected over time but there  is  theoretical
129              chance that hashes can collide as size of SCSI key is quite lim‐
130              ited. (Default Value: id)
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132       --sg_persist-path=[path]
133              Path to sg_persist binary (Default  Value:  /usr/bin/sg_persist)
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136       --sg_turs-path=[path]
137              Path to sg_turs binary (Default Value: /usr/bin/sg_turs)
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139       --vgs-path=[path]
140              Path to vgs binary (Default Value: /usr/sbin/vgs)
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ACTIONS

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146       on     Power on machine.
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148       off    Power off machine.
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150       status This returns the status of the plug/virtual machine.
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152       monitor
153              Check the health of fence device
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155       metadata
156              Display the XML metadata describing this resource.
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158       manpage
159               The operational behavior of this is not known.
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161       validate-all
162              Validate if all required parameters are entered.
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STDIN PARAMETERS

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168       action Fencing action (Default Value: off)
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170       aptpl  Use  the  APTPL flag for registrations. This option is only used
171              for the 'on' action.
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173       devices
174              List of devices to use for current  operation.  Devices  can  be
175              comma-separated  list of raw devices (eg. /dev/sdc). Each device
176              must support SCSI-3 persistent reservations.
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178       key    Key to use for the current operation. This key should be  unique
179              to a node. For the "on" action, the key specifies the key use to
180              register the local node. For the "off" action, this  key  speci‐
181              fies the key to be removed from the device(s).
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183       plug   Name of the node to be fenced. The node name is used to generate
184              the key value used for the current operation. This  option  will
185              be  ignored  when  used  with  the  -k option. This parameter is
186              always required. Obsoletes: port
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188       readonly
189              Open DEVICE read-only.
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191       logfile
192              Log output (stdout and stderr) to file
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194       quiet  Disable logging to stderr. Does not affect --verbose or --debug-
195              file or logging to syslog.
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197       verbose
198              Verbose  mode.  Multiple  -v flags can be stacked on the command
199              line (e.g., -vvv) to increase verbosity.
200
201       verbose_level
202              Level of debugging detail in output. Defaults to the  number  of
203              --verbose  flags  specified on the command line, or to 1 if ver‐
204              bose=1 in a  stonith  device  configuration  (i.e.,  on  stdin).
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207       debug_file
208              Write debug information to given file Obsoletes: debug
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210       version
211              Display version information and exit
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213       help   Display help and exit
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215       delay  Wait  X  seconds  before  fencing  is started (Default Value: 0)
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218       disable_timeout
219              Disable timeout (true/false) (default: true when run from  Pace‐
220              maker 2.0+)
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222       login_timeout
223              Wait  X  seconds  for  cmd prompt after login (Default Value: 5)
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226       power_timeout
227              Test X seconds for status change after  ON/OFF  (Default  Value:
228              20)
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230       power_wait
231              Wait X seconds after issuing ON/OFF (Default Value: 0)
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233       shell_timeout
234              Wait  X  seconds  for  cmd prompt after issuing command (Default
235              Value: 3)
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237       retry_on
238              Count of attempts to retry power on (Default Value: 1)
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240       corosync_cmap_path
241              Path    to    corosync-cmapctl    binary     (Default     Value:
242              /usr/sbin/corosync-cmapctl)
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244       key_value
245              Method  used  to  generate the SCSI key. "id" (default) uses the
246              positional ID from "corosync-cmactl nodelist" output  which  can
247              get  inconsistent  when  nodes  are removed from cluster without
248              full cluster restart. "hash" uses part of hash made out of  node
249              names  which  is not affected over time but there is theoretical
250              chance that hashes can collide as size of SCSI key is quite lim‐
251              ited. (Default Value: id)
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253       sg_persist_path
254              Path  to  sg_persist binary (Default Value: /usr/bin/sg_persist)
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257       sg_turs_path
258              Path to sg_turs binary (Default Value: /usr/bin/sg_turs)
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260       vgs_path
261              Path to vgs binary (Default Value: /usr/sbin/vgs)
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265fence_scsi (Fence Agent)          2009-10-20                    FENCE_AGENT(8)
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