xref: /freebsd/sbin/savecore/savecore.8 (revision 7bd6fde3)
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28.\"     From: @(#)savecore.8	8.1 (Berkeley) 6/5/93
29.\" $FreeBSD$
30.\"
31.Dd February 24, 2005
32.Dt SAVECORE 8
33.Os
34.Sh NAME
35.Nm savecore
36.Nd "save a core dump of the operating system"
37.Sh SYNOPSIS
38.Nm
39.Fl c
40.Nm
41.Fl C
42.Op Fl v
43.Op Ar directory device
44.Nm
45.Op Fl fkvz
46.Op Ar directory Op Ar device ...
47.Sh DESCRIPTION
48The
49.Nm
50utility
51copies a core dump into
52.Ar directory ,
53or the current working directory if no
54.Ar directory
55argument is given,
56and enters a reboot message and information about the core dump into
57the system log.
58.Pp
59The options are as follows:
60.Bl -tag -width indent
61.It Fl C
62Check to see if a dump exists,
63and display a brief message to indicate the status.
64An exit status of 0 indicates that a dump is there,
651 indicates that none exists.
66This option is compatible only with the
67.Op Fl v
68option.
69.It Fl c
70Clear the dump, so that future invocations of
71.Nm
72will ignore it.
73.It Fl f
74Force a dump to be taken even if either the dump was cleared or if the
75dump header information is inconsistent.
76.It Fl k
77Do not clear the dump after saving it.
78.It Fl v
79Print out some additional debugging information.
80Specify twice for more information.
81.It Fl z
82Compress the core dump and kernel (see
83.Xr gzip 1 ) .
84.El
85.Pp
86The
87.Nm
88utility
89looks for dumps on each device specified by the
90.Ar device
91argument(s), or on each device in
92.Pa /etc/fstab
93marked as
94.Dq dump
95or
96.Dq swap .
97The
98.Nm
99utility
100checks the core dump in various ways to make sure that it is complete.
101If it passes these checks, it saves the core image in
102.Ar directory Ns Pa /vmcore.#
103and information about the core in
104.Ar directory Ns Pa /info.#
105The ``#'' is the number from the first line of the file
106.Ar directory Ns Pa /bounds ,
107and it is incremented and stored back into the file each time
108.Nm
109successfully runs.
110.Pp
111The
112.Nm
113utility
114also checks the available disk space before attempting to make the copies.
115If there is insufficient disk space in the file system containing
116.Ar directory ,
117or if the file
118.Ar directory Ns Pa /minfree
119exists and the number of free kilobytes (for non-superusers) in the
120file system after the copies were made would be less than the number
121in the first line of this file, the copies are not attempted.
122.Pp
123If
124.Nm
125successfully copies the kernel and the core dump, the core dump is cleared
126so that future invocations of
127.Nm
128will ignore it.
129.Pp
130The
131.Nm
132utility
133is meant to be called near the end of the initialization file
134.Pa /etc/rc
135(see
136.Xr rc 8 ) .
137.Sh SEE ALSO
138.Xr gzip 1 ,
139.Xr getbootfile 3 ,
140.Xr dumpon 8 ,
141.Xr syslogd 8
142.Sh HISTORY
143The
144.Nm
145utility appeared in
146.Bx 4.1 .
147.Sh BUGS
148The minfree code does not consider the effect of compression or sparse files.
149