1.\" Copyright (c) 1980, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.Dd April 4, 2022 29.Dt SAVECORE 8 30.Os 31.Sh NAME 32.Nm savecore 33.Nd "save a core dump of the operating system" 34.Sh SYNOPSIS 35.Nm 36.Fl c 37.Op Fl v 38.Op Ar device ... 39.Nm 40.Fl C 41.Op Fl v 42.Op Ar device ... 43.Nm 44.Fl L 45.Op Fl fvZz 46.Op Fl m Ar maxdumps 47.Op Ar directory 48.Nm 49.Op Fl -libxo 50.Op Fl fkuvz 51.Op Fl m Ar maxdumps 52.Op Ar directory Op Ar device ... 53.Sh DESCRIPTION 54The 55.Nm 56utility 57copies a core dump into 58.Ar directory , 59or the current working directory if no 60.Ar directory 61argument is given, 62and enters a reboot message and information about the core dump into 63the system log. 64.Pp 65The options are as follows: 66.Bl -tag -width ".Fl m Ar maxdumps" 67.It Fl -libxo 68Generate output via 69.Xr libxo 3 70in a selection of different human and machine readable formats. 71See 72.Xr xo_parse_args 3 73for details on command line arguments. 74.It Fl C 75Check to see if a dump exists, 76and display a brief message to indicate the status. 77An exit status of 0 indicates that a dump is there, 781 indicates that none exists. 79This option is compatible only with the 80.Op Fl v 81option. 82.It Fl c 83Clear the dump, so that future invocations of 84.Nm 85will ignore it. 86.It Fl f 87Force a dump to be taken even if either the dump was cleared or if the 88dump header information is inconsistent. 89.It Fl k 90Do not clear the dump after saving it. 91.It Fl L 92Instruct 93.Nm 94to generate and save a kernel dump of the running system, rather than 95copying one from a dump device. 96.It Fl m Ar maxdumps 97Maximum number of dumps to store. 98Once the number of stored dumps is equal to 99.Ar maxdumps 100the counter will restart from 101.Dv 0 . 102.It Fl u 103Uncompress the dump in case it was compressed by the kernel. 104.It Fl v 105Print out some additional debugging information. 106Specify twice for more information. 107.It Fl Z 108Compress the dump (see 109.Xr zstd 1 ) . 110This option is only supported in conjunction with the 111.Fl L 112option. 113Regular dumps can be configured for compression with zstd using 114.Xr dumpon 8 . 115.It Fl z 116Compress the dump (see 117.Xr gzip 1 ) . 118The dump may already be compressed if the kernel was configured to 119do so by 120.Xr dumpon 8 . 121In this case, the option has no effect. 122.Pp 123If used in conjunction with the 124.Fl L 125option, the requested live dump will be compressed with gzip. 126.El 127.Pp 128The 129.Nm 130utility 131looks for dumps on each device specified by the 132.Ar device 133argument(s), or on each device in 134.Pa /etc/fstab 135marked as 136.Dq dump 137or 138.Dq swap . 139The 140.Nm 141utility 142checks the core dump in various ways to make sure that it is complete. 143If it passes these checks, it saves the core image in 144.Ar directory Ns Pa /vmcore.# 145and information about the core in 146.Ar directory Ns Pa /info.# . 147If the core is encrypted, it saves the dump key in 148.Ar directory Ns Pa /key.# . 149The core can be later decrypted using 150.Xr decryptcore 8 . 151For kernel textdumps generated with the 152.Xr textdump 4 153facility, output will be stored in the 154.Xr tar 5 155format and named 156.Ar directory Ns Pa /textdump.tar.# . 157The 158.Dq # 159is the number from the first line of the file 160.Ar directory Ns Pa /bounds , 161and it is incremented and stored back into the file each time 162.Nm 163successfully runs. 164.Pp 165The 166.Nm 167utility 168also checks the available disk space before attempting to make the copies. 169If there is insufficient disk space in the file system containing 170.Ar directory , 171or if the file 172.Ar directory Ns Pa /minfree 173exists and the number of free kilobytes (for non-superusers) in the 174file system after the copies were made would be less than the number 175in the first line of this file, the copies are not attempted. 176.Pp 177If 178.Nm 179successfully copies the kernel and the core dump, the core dump is cleared 180so that future invocations of 181.Nm 182will ignore it. 183.Pp 184The 185.Nm 186utility 187is meant to be called near the end of the initialization file 188.Pa /etc/rc 189(see 190.Xr rc 8 ) . 191.Sh SEE ALSO 192.Xr gzip 1 , 193.Xr zstd 1 , 194.Xr getbootfile 3 , 195.Xr libxo 3 , 196.Xr xo_parse_args 3 , 197.Xr mem 4 , 198.Xr textdump 4 , 199.Xr tar 5 , 200.Xr crashinfo 8 , 201.Xr decryptcore 8 , 202.Xr dumpon 8 , 203.Xr syslogd 8 204.Sh HISTORY 205The 206.Nm 207utility appeared in 208.Bx 4.1 . 209.Pp 210Support for kernel textdumps appeared in 211.Fx 7.1 . 212.Sh BUGS 213The minfree code does not consider the effect of compression or sparse files. 214