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diff --git a/static/freebsd/man8/crash.8 3.html b/static/freebsd/man8/crash.8 3.html new file mode 100644 index 00000000..c1e0a796 --- /dev/null +++ b/static/freebsd/man8/crash.8 3.html @@ -0,0 +1,125 @@ +<table class="head"> + <tr> + <td class="head-ltitle">CRASH(8)</td> + <td class="head-vol">System Manager's Manual</td> + <td class="head-rtitle">CRASH(8)</td> + </tr> +</table> +<div class="manual-text"> +<section class="Sh"> +<h1 class="Sh" id="NAME"><a class="permalink" href="#NAME">NAME</a></h1> +<p class="Pp"><code class="Nm">crash</code> — <span class="Nd">FreeBSD + system failures</span></p> +</section> +<section class="Sh"> +<h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1> +<p class="Pp">This section explains a bit about system crashes and (very + briefly) how to analyze crash dumps.</p> +<p class="Pp">When the system crashes voluntarily it prints a message of the + form</p> +<dl class="Bl-diag Bd-indent"> + <dt>panic: why i gave up the ghost</dt> + <dd></dd> +</dl> +<p class="Pp">on the console, and if dumps have been enabled (see + <a class="Xr">dumpon(8)</a>), takes a dump on a mass storage peripheral, and + then invokes an automatic reboot procedure as described in + <a class="Xr">reboot(8)</a>. Unless some unexpected inconsistency is + encountered in the state of the file systems due to hardware or software + failure, the system will then resume multi-user operations.</p> +<p class="Pp">The system has a large number of internal consistency checks; if + one of these fails, then it will panic with a very short message indicating + which one failed. In many instances, this will be the name of the routine + which detected the error, or a two-word description of the inconsistency. A + full understanding of most panic messages requires perusal of the source + code for the system.</p> +<p class="Pp">The most common cause of system failures is hardware failure, + which can reflect itself in different ways. Here are the messages which are + most likely, with some hints as to causes. Left unstated in all cases is the + possibility that hardware or software error produced the message in some + unexpected way.</p> +<p class="Pp"></p> +<dl class="Bl-diag Bl-compact"> + <dt>Mounting from <device> failed with error <err></dt> + <dd>The system was unable to mount the configured root filesystem. Either the + root filesystem has been corrupted, or the system is attempting to use the + wrong device as root filesystem. + <p class="Pp" id="mountroot_">This is not a panic message; rather it is + followed by an interactive + <a class="permalink" href="#mountroot_"><b class="Sy">mountroot></b></a> + prompt where the operator can list detected devices and filesystems, and + select an alternative root filesystem to mount. Alternatively, the + system can be booted from recovery media to repair the situation. The + system install media provides a live environment which is suitable for + this task.</p> + <p class="Pp"></p> + </dd> + <dt>init: not found</dt> + <dd>This is not a panic message, as reboots are likely to be futile. Late in + the bootstrap procedure, the system was unable to locate and execute the + initialization process, <a class="Xr">init(8)</a>. The root file system is + incorrect or has been corrupted, or the mode or type of + <span class="Pa">/sbin/init</span> forbids execution or is totally + missing. + <p class="Pp"></p> + </dd> + <dt>ffs_realloccg: bad optim</dt> + <dd></dd> + <dt>ffs_valloc: dup alloc</dt> + <dd></dd> + <dt>ffs_alloccgblk: cyl groups corrupted</dt> + <dd></dd> + <dt>ffs_alloccg: map corrupted</dt> + <dd></dd> + <dt>blkfree: freeing free block</dt> + <dd></dd> + <dt>blkfree: freeing free frag</dt> + <dd></dd> + <dt>ifree: freeing free inode</dt> + <dd>These panic messages are among those that may be produced when file system + inconsistencies are detected. The problem generally results from a failure + to repair damaged file systems after a crash, hardware failures, or other + condition that should not normally occur. A file system check will + normally correct the problem. + <p class="Pp"></p> + </dd> + <dt>init died (signal #, exit #)</dt> + <dd>The system initialization process has exited with the specified signal + number and exit code. This is bad news, as no new users will then be able + to log in. Rebooting is the only fix, so the system just does it right + away.</dd> +</dl> +<p class="Pp">That completes the list of panic types you are likely to see.</p> +<p class="Pp">If the system has been configured to take crash dumps (see + <a class="Xr">dumpon(8)</a>), then when it crashes it will write (or at + least attempt to write) an image of memory into the back end of the dump + device, usually the same as the primary swap area. After the system is + rebooted, the program <a class="Xr">savecore(8)</a> runs and preserves a + copy of this core image and the current system in a specified directory for + later perusal. See <a class="Xr">savecore(8)</a> for details.</p> +<p class="Pp">To analyze a dump you should begin by running + <a class="Xr">kgdb(1)</a> (<span class="Pa">ports/devel/gdb</span>) on the + system load image and core dump. If the core image is the result of a panic, + the panic message is printed. For more details consult the chapter on kernel + debugging in the <i class="RsB">FreeBSD Developers' Handbook</i> + (<span class="Pa">https://www.freebsd.org/doc/en/books/developers-handbook/</span>).</p> +</section> +<section class="Sh"> +<h1 class="Sh" id="SEE_ALSO"><a class="permalink" href="#SEE_ALSO">SEE + ALSO</a></h1> +<p class="Pp"><a class="Xr">kgdb(1)</a> + (<span class="Pa">ports/devel/gdb</span>), <a class="Xr">dumpon(8)</a>, + <a class="Xr">reboot(8)</a>, <a class="Xr">savecore(8)</a></p> +</section> +<section class="Sh"> +<h1 class="Sh" id="HISTORY"><a class="permalink" href="#HISTORY">HISTORY</a></h1> +<p class="Pp">The <code class="Nm">crash</code> manual page first appeared in + <span class="Ux">FreeBSD 2.2</span>.</p> +</section> +</div> +<table class="foot"> + <tr> + <td class="foot-date">July 25, 2025</td> + <td class="foot-os">FreeBSD 15.0</td> + </tr> +</table> |