Drop hurd specific dependency on libc0.3 (>= 2.3.2.ds1-12). It is
[sysvinit.git] / man / halt.8
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18 .\"{{{}}}
19 .\"{{{ Title
20 .TH HALT 8 "Nov 6, 2001" "" "Linux System Administrator's Manual"
21 .\"}}}
22 .\"{{{ Name
23 .SH NAME
24 halt, reboot, poweroff \- stop the system.
25 .\"}}}
26 .\"{{{ Synopsis
27 .SH SYNOPSIS
28 .B /sbin/halt
29 .RB [ \-n ]
30 .RB [ \-w ]
31 .RB [ \-d ]
32 .RB [ \-f ]
33 .RB [ \-i ]
34 .RB [ \-p ]
35 .RB [ \-h ]
36 .br
37 .B /sbin/reboot
38 .RB [ \-n ]
39 .RB [ \-w ]
40 .RB [ \-d ]
41 .RB [ \-f ]
42 .RB [ \-i ]
43 .br
44 .B /sbin/poweroff
45 .RB [ \-n ]
46 .RB [ \-w ]
47 .RB [ \-d ]
48 .RB [ \-f ]
49 .RB [ \-i ]
50 .RB [ \-h ]
51 .\"}}}
52 .\"{{{ Description
53 .SH DESCRIPTION
54 \fBHalt\fP notes that the system is being brought down in the file
55 \fI/var/log/wtmp\fP, and then either tells the kernel to halt, reboot or
56 power-off the system.
57 .PP
58 If \fBhalt\fP or \fBreboot\fP is called when the system is
59 \fInot\fP in runlevel \fB0\fP or \fB6\fP, in other words when it's running
60 normally, \fBshutdown\fP will be invoked instead (with the \fB-h\fP
61 or \fB-r\fP flag). For more info see the \fBshutdown\fP(8)
62 manpage.
63 .PP
64 The rest of this manpage describes the behaviour in runlevels 0
65 and 6, that is when the systems shutdown scripts are being run.
66 .\"}}}
67 .\"{{{ Options
68 .SH OPTIONS
69 .IP \fB\-n\fP
70 Don't sync before reboot or halt. Note that the kernel and storage
71 drivers may still sync.
72 .IP \fB\-w\fP
73 Don't actually reboot or halt but only write the wtmp record
74 (in the \fI/var/log/wtmp\fP file).
75 .IP \fB\-d\fP
76 Don't write the wtmp record. The \fB\-n\fP flag implies \fB\-d\fP.
77 .IP \fB\-f\fP
78 Force halt or reboot, don't call \fBshutdown\fP(8).
79 .IP \fB\-i\fP
80 Shut down all network interfaces just before halt or reboot.
81 .IP \fB\-h\fP
82 Put all hard drives on the system in stand-by mode just before halt or power-off.
83 .IP \fB\-p\fP
84 When halting the system, switch off the power. This is the default when halt is
85 called as \fBpoweroff\fP.
86 .\"}}}
87 .\"{{{ Diagnostics
88 .SH DIAGNOSTICS
89 If you're not the superuser, you will get the message `must be superuser'.
90 .\"}}}
91 .\"{{{ Notes
92 .SH NOTES
93 Under older \fBsysvinit\fP releases , \fBreboot\fP and \fBhalt\fP should
94 never be called directly. From release 2.74 on \fBhalt\fP and \fBreboot\fP
95 invoke \fBshutdown\fP(8) if the system is not in runlevel 0 or 6. This
96 means that if \fBhalt\fP or \fBreboot\fP cannot find out the current
97 runlevel (for example, when \fI/var/run/utmp\fP hasn't been initialized
98 correctly) \fBshutdown\fP will be called, which might not be what you want.
99 Use the \fB-f\fP flag if you want to do a hard \fBhalt\fP or \fBreboot\fP.
100 .PP
101 The \fB-h\fP flag puts all hard disks in standby mode just before halt
102 or power-off. Right now this is only implemented for IDE drives. A side
103 effect of putting the drive in stand-by mode is that the write cache
104 on the disk is flushed. This is important for IDE drives, since the
105 kernel doesn't flush the write cache itself before power-off.
106 .PP
107 The \fBhalt\fP program uses /proc/ide/hd* to find all IDE disk devices,
108 which means that \fI/proc\fP needs to be mounted when \fBhalt\fP or
109 \fBpoweroff\fP is called or the \fB-h\fP switch will do nothing.
110 .PP
111 .\"}}}
112 .\"{{{ Author
113 .SH AUTHOR
114 Miquel van Smoorenburg, miquels@cistron.nl
115 .\"}}}
116 .\"{{{ See also
117 .SH "SEE ALSO"
118 .BR shutdown (8),
119 .BR init (8)
120 .\"}}}