xref: /freebsd/sbin/savecore/savecore.8 (revision 39beb93c3f8bdbf72a61fda42300b5ebed7390c8)
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28.\"     From: @(#)savecore.8	8.1 (Berkeley) 6/5/93
29.\" $FreeBSD$
30.\"
31.Dd December 24, 2008
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.#
105For kernel textdumps generated with the
106.Xr textdump 4
107facility, output will be stored in the
108.Xr tar 5
109format and named
110.Ar director Ns Pa /textdump.tar.#
111The ``#'' is the number from the first line of the file
112.Ar directory Ns Pa /bounds ,
113and it is incremented and stored back into the file each time
114.Nm
115successfully runs.
116.Pp
117The
118.Nm
119utility
120also checks the available disk space before attempting to make the copies.
121If there is insufficient disk space in the file system containing
122.Ar directory ,
123or if the file
124.Ar directory Ns Pa /minfree
125exists and the number of free kilobytes (for non-superusers) in the
126file system after the copies were made would be less than the number
127in the first line of this file, the copies are not attempted.
128.Pp
129If
130.Nm
131successfully copies the kernel and the core dump, the core dump is cleared
132so that future invocations of
133.Nm
134will ignore it.
135.Pp
136The
137.Nm
138utility
139is meant to be called near the end of the initialization file
140.Pa /etc/rc
141(see
142.Xr rc 8 ) .
143.Sh SEE ALSO
144.Xr gzip 1 ,
145.Xr getbootfile 3 ,
146.Xr textdump 4 ,
147.Xr tar 5 ,
148.Xr dumpon 8 ,
149.Xr syslogd 8
150.Sh HISTORY
151The
152.Nm
153utility appeared in
154.Bx 4.1 .
155.Pp
156Support for kernel textdumps appeared in
157.Fx 8.0 .
158.Sh BUGS
159The minfree code does not consider the effect of compression or sparse files.
160