---
source/dump.xml | 113 ++++++++++++++++++++++++++++++++++++++++++++++++++++--
1 files changed, 108 insertions(+), 5 deletions(-)
diff --git a/source/dump.xml b/source/dump.xml
index 3879bbe..5c09aa1 100644
--- a/source/dump.xml
+++ b/source/dump.xml
@@ -5,20 +5,123 @@
<description>
<text>
- Core dump a guest domain
+ dump the core of a domain to a file for analysis
</text>
</description>
- <options />
+ <options>
+ <parameter requirement="optional">
+ <keyword requirement="optional">--live</keyword>
+ <description>
+ <text>
+ perform a live core dump if supported
+ </text>
+ </description>
+ </parameter>
+ <parameter requirement="optional">
+ <keyword requirement="optional">--crach</keyword>
+ <description>
+ <text>
+ crash the domain after core dump
+ </text>
+ </description>
+ </parameter>
+ <parameter requirement="optional">
+ <keyword requirement="optional">--bypass-cache</keyword>
+ <description>
+ <text>
+ avoid file system cache when dumping
+ </text>
+ </description>
+ </parameter>
+ <parameter requirement="required">
+ <keyword requirement="optional">--domain</keyword>
+ <value type="string"
requirement="required">domain</value>
+ <description>
+ <text>
+ domain name, id or uuid
+ </text>
+ <text>
+ "--domain" itself is optional
+ </text>
+ </description>
+ </parameter>
+ <parameter requirement="required">
+ <keyword requirement="optional">--file</keyword>
+ <value type="string"
requirement="required">file</value>
+ <description>
+ <text>
+ file in which the core of the domain is saved
+ </text>
+ <text>
+ '--file' itself is optional
+ </text>
+ </description>
+ </parameter>
+ </options>
<availability from="0.1.9" />
<notes />
- <examples type="usage" />
+ <examples type="usage">
+ <example>
+ <terminal>virsh # <bold>dump</bold>
<value>example-domain</value>
<value>/mnt/data/dumps/example-domain.dump</value></terminal>
+ <text>
+ Dumps the core of <value>example-domain</value> to file
<value>/mnt/data/dumps/example-domain.dump</value>.
+ </text>
+ </example>
+ </examples>
- <examples type="fullcontext" />
+ <examples type="fullcontext">
+ <example>
+ <text>
+ In this example we will dump the core of a domain and analysis it
+ using a tool called crash.
+ </text>
+ <text>
+ For the purpose of showing how to use virsh dump combined with crash,
+ we will crash the domain by pressing ALT-SysRq-c, the SysRq command
+ to crash system by a NULL pointer dereference. Steps are:
+ </text>
+ <text>
+ Enable SysRq in example-domain:
+ </text>
+ <terminal>example-domain# echo 1 >
/proc/sys/kernel/sysrq</terminal>
+ <text>
+ Disable kdump in example-domain:
+ </text>
+ <terminal>example-domain# /etc/init.d/kdump stop</terminal>
+ <text>
+ Send key ALT-SysRq-c:
+ </text>
+ <terminal>virsh # <bold>send-key</bold>
<value>example-domain</value> KEY_LEFTALT KEY_SYSRQ KEY_C</terminal>
+ <text>
+ Now example-domain is crashed, dump the core of it:
+ </text>
+ <terminal>virsh # dump example-domain
/mnt/data/dumps/example-domain.dump</terminal>
+ <text>
+ After dump finished, we can analysis the core file by crash:
+ </text>
+ <terminal>crash /patch/to/vmlinux
/mnt/data/dumps/example-domain.dump</terminal>
+ <text>
+ the vmlinux is the file containing debug information, usually it locates at the
root
+ of kernel source dir if you compile the kernel by yourself, or is shipped with
package
+ kernel-debuginfo.
+ </text>
+ </example>
+ </examples>
- <reference type="seealso" />
+ <reference type="seealso">
+ <item>
+ <link type="external"
href="http://people.redhat.com/anderson/" />
+ <name>
+ crash
+ </name>
+ <description>
+ Kernel analysis utility for live systems, netdump, diskdump, kdump, LKCD or mcore
dumpfiles
+ </description>
+ </item>
+ </reference>
</command>
--
1.7.3.1