1SBD(8) STONITH Block Device SBD(8)
2
6 sbd - STONITH Block Device daemon
7
9 sbd [options] "command"
10
12 The SBD (Storage-Based Death) daemon integrates with Pacemaker and a
13 watchdog device to arrange for nodes to reliably self-terminate when
14 fencing is required. SBD can be particularly useful in environments
15 where traditional fencing mechanisms are not possible.
16 This build of SBD has message exchanging via a shared block storage
18 disabled to solely serve the above purpose.
19 GENERAL OPTIONS
21 -v Enable some verbose debug logging.
22 -h Display a concise summary of "sbd" options.
24 -n node
26 Set local node name; defaults to "uname -n". This should not need
27 to be set.
28 -R Do not enable realtime priority. By default, "sbd" runs at realtime
30 priority, locks itself into memory, and also acquires highest IO
31 priority to protect itself against interference from other
32 processes on the system. This is a debugging-only option.
33 watch
35 Example usage:
36 sbd -W -P watch
38 This command will make "sbd" start in daemon mode. It will constantly
40 monitor corosync/pacemaker_remoted and optionally take Pacemaker's
41 state into account.
42 "sbd" must be started on boot before the cluster stack! See below for
44 enabling this according to your boot environment.
45 The options for this mode are rarely specified directly on the
47 commandline directly, but most frequently set via /etc/sysconfig/sbd.
48 For this build withouth block device integration configuration of a
50 watchdog is mandatory. The watchdog is activated at initial start of
51 the sbd daemon.
52 There is one "sbd" process that acts as a master to which all watchers
54 report; one for corosync/pacemaker_remote; and, optionally, one that
55 handles the Pacemaker integration.
56 -W Enable or disable use of the system watchdog to protect against the
58 sbd processes failing and the node being left in an undefined
59 state. Specify this once to enable, twice to disable.
60 Defaults to enabled.
62 -w /dev/watchdog
64 This can be used to override the default watchdog device used and
65 should not usually be necessary.
66 -p /var/run/sbd.pid
68 This option can be used to specify a pidfile for the main sbd
69 process.
70 -F N
72 Number of failures before a failing servant process will not be
73 restarted immediately until the dampening delay has expired. If set
74 to zero, servants will be restarted immediately and indefinitely.
75 If set to one, a failed servant will be restarted once every -t
76 seconds. If set to a different value, the servant will be restarted
77 that many times within the dampening period and then delay.
78 Defaults to 1.
80 -t N
82 Dampening delay before faulty servants are restarted. Combined with
83 "-F 1", the most logical way to tune the restart frequency of
84 servant processes. Default is 5 seconds.
85 If set to zero, processes will be restarted indefinitely and
87 immediately.
88 -P Check Pacemaker quorum and node health.
90 -Z Enable trace mode. Warning: this is unsafe for production, use at
92 your own risk! Specifying this once will turn all reboots or power-
93 offs, be they caused by self-fence decisions or messages, into a
94 crashdump. Specifying this twice will just log them but not
95 continue running.
96 -T By default, the daemon will set the watchdog timeout as specified
98 in the device metadata. However, this does not work for every
99 watchdog device. In this case, you must manually ensure that the
100 watchdog timeout used by the system correctly matches the SBD
101 settings, and then specify this option to allow "sbd" to continue
102 with start-up.
103
105 Configure a watchdog
106 The only purpose of this build of sbd is to give pacemaker access to a
107 hardware watchdog. Thus it is mandatory that you configure your Linux
108 system to load a watchdog driver with hardware assistance (as is
109 available on most modern systems), such as hpwdt, iTCO_wdt, or others.
110 As a fall-back, you can use the softdog module.
111 No other software must access the watchdog timer; it can only be
113 accessed by one process at any given time. Some hardware vendors ship
114 systems management software that use the watchdog for system resets
115 (f.e. HP ASR daemon). Such software has to be disabled if the watchdog
116 is to be used by SBD.
117 Configure SBD to start on boot
119 On systems using "sysvinit", the "openais" or "corosync" system start-
120 up scripts must handle starting or stopping "sbd" as required before
121 starting the rest of the cluster stack.
122 For "systemd", sbd simply has to be enabled using
124 systemctl enable sbd.service
126 The daemon is brought online on each node before corosync and Pacemaker
128 are started, and terminated only after all other cluster components
129 have been shut down - ensuring that cluster resources are never
130 activated without SBD supervision.
131 Configuration via sysconfig
133 The system instance of "sbd" is configured via /etc/sysconfig/sbd. In
134 this file, you must specify the watchdog-device used, as well as any
135 options to pass to the daemon:
136 SBD_WATCHDOG_DEV=/dev/watchdog
138 SBD_PACEMAKER="true"
139
141 General cluster properties
142 You must also enable STONITH in general, and set the stonith-watchdog-
143 timeout to be at least twice the timeout you have configured for the
144 hardware watchdog. If that timeout is 5 seconds, this is a possible
145 configuration:
146 property stonith-watchdog-timeout="10s"
148
150 Copyright (C) 2008-2013 Lars Marowsky-Bree
151 Copyright (C) 2014-2016 Andrew Beekhof
153 This program is free software; you can redistribute it and/or modify it
155 under the terms of the GNU General Public License as published by the
156 Free Software Foundation; either version 2 of the License, or (at your
157 option) any later version.
158 This software is distributed in the hope that it will be useful, but
160 WITHOUT ANY WARRANTY; without even the implied warranty of
161 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
162 General Public License for more details.
163 For details see the GNU General Public License at
165 http://www.gnu.org/licenses/gpl-2.0.html (version 2) and/or
166 http://www.gnu.org/licenses/gpl.html (the newest as per "any later").
167SBD 2017-03-22 SBD(8)