3 virt-uname - system information for virtual machines
5 virt-dmesg - print kernel messages for virtual machines
9 virt-uname [-options] [domains...]
11 virt-dmesg [-options] [domains...]
15 These virtualization tools allow you to inspect the status of
16 virtual machines running Linux.
18 The tools all use libvirt so are capable of showing stats across a
19 variety of different virtualization systems.
23 Each command obeys a common set of options. The general form is:
25 virt-I<program> [-options] [domains...]
27 where I<domains> is a list of guest names to act on. If no domains
28 are specified then we act on all active domains by default.
30 A I<domain> may be specified either by its name or by its ID. Use
31 I<virsh list> to get a list of active domain names and IDs.
33 The virt-mem tools do not work on domains which are not active
34 (running or paused). eg. They do not work on shut down domains.
38 =item B<-c uri>, B<--connect uri>
40 Connect to libvirt URI. The default is to connect to the default
41 libvirt URI, normally Xen.
45 Print the results in CSV format, suitable for importing into a
46 spreadsheet or database.
48 This option is only supported if virt-mem was built with CSV support.
52 Emit debugging information on stderr. Please supply this if you
57 Display usage summary.
59 =item B<-t memoryimage>
61 Test mode. Instead of checking libvirt for domain information, this
62 runs the virt-mem tool directly on the memory image supplied. You may
63 specify the B<-t> option multiple times.
67 Display version and exit.
69 =item B<-E auto|littleendian|bigendian>
71 =item B<-T auto|i386|x86-64|I<address>>
73 =item B<-W auto|32|64>
75 These options force the endianness, text address, and word size for
76 the subsequent domains listed on the command line (or if no domains
77 are listed, then for all domains).
79 These default to I<auto> which tries to do automatic detection (using
80 libvirt, or details from the memory images themselves). You only need
81 to use these options if virt-mem tools get the automatic detection
84 Endianness (I<-E>) sets the memory endianness, for data, pointers and
87 Text address (I<-T>) sets the base address of the kernel image. I<-T
88 i386> means to try some common addresses for i386-based kernels. I<-T
89 x86-64> means to try some common addresses for x86-64-based kernels.
90 I<-T I<address>> sets the address specifically (I<0x> prefix is
91 allowed to specify hex addresses).
93 Word size (I<-W>) sets the word size, 32 or 64 bits.
95 =item B<-A auto|i386|x86-64|...>
97 This option sets the architecture to one of a collection of known
98 architectures. It is equivalent to setting endianness and wordsize in
99 one go, but not text address.
106 f9x32kvm: Linux localhost.localdomain 2.6.24-0.155.rc7.git6.fc9 #1
107 SMP Tue Jan 15 17:52:31 EST 2008 i686 (none)
109 # virt-dmesg f9x32kvm | tail
110 <6>Bluetooth: Core ver 2.11
111 <6>NET: Registered protocol family 31
112 <6>Bluetooth: HCI device and connection manager initialized
113 <6>Bluetooth: HCI socket layer initialized
114 <6>Bluetooth: L2CAP ver 2.9
115 <6>Bluetooth: L2CAP socket layer initialized
116 <6>Bluetooth: RFCOMM socket layer initialized
117 <6>Bluetooth: RFCOMM TTY layer initialized
118 <6>Bluetooth: RFCOMM ver 1.8
119 <7>eth0: no IPv6 routers present
123 The virt-mem tools spy on the guest's memory image. There are some
124 shortcomings to this, described here.
126 (1) Only works on specific, tested releases of Linux kernels. Support
127 for arbitrary Linux kernel versions may be patchy because of changes
128 in the internal structures used. Support for non-Linux kernels is
129 currently non-existent, and probably impossible for Windows because of
130 lack of an acceptable source license.
132 (2) Heuristics are used which may mean in the worst case that the
135 (3) Structures which are frequently modified may cause errors. This
136 could be a problem if, for example, the process table in the guest is
137 being rapidly updated.
139 (4) We have to scan memory to find kernel symbols, etc., which can be
140 quite slow. Optimizing the memory scanner would help, and caching the
141 base address of the symbol table(s) would make it dramatically faster.
145 The current code tries hard to be secure against malicious guests, for
146 example guests which set up malicious kernel memory.
154 L<http://www.libvirt.org/ocaml/>,
155 L<http://www.libvirt.org/>,
156 L<http://et.redhat.com/~rjones/>,
157 L<http://caml.inria.fr/>
161 Richard W.M. Jones <rjones @ redhat . com>
165 (C) Copyright 2008 Red Hat Inc., Richard W.M. Jones
168 This program is free software; you can redistribute it and/or modify
169 it under the terms of the GNU General Public License as published by
170 the Free Software Foundation; either version 2 of the License, or
171 (at your option) any later version.
173 This program is distributed in the hope that it will be useful,
174 but WITHOUT ANY WARRANTY; without even the implied warranty of
175 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
176 GNU General Public License for more details.
178 You should have received a copy of the GNU General Public License
179 along with this program; if not, write to the Free Software
180 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
182 =head1 REPORTING BUGS
184 Bugs can be viewed on the Red Hat Bugzilla page:
185 L<https://bugzilla.redhat.com/>.
187 If you find a bug in virt-mem, please follow these steps to report it:
191 =item 1. Check for existing bug reports
193 Go to L<https://bugzilla.redhat.com/> and search for similar bugs.
194 Someone may already have reported the same bug, and they may even
197 =item 2. Capture debug and error messages
201 virt-I<program> --debug > virt-mem.log 2>&1
203 and keep I<virt-mem.log>. It contains error messages which you should
204 submit with your bug report.
206 =item 3. Get version of virt-mem and version of libvirt.
210 virt-I<program> --version
212 =item 4. Submit a bug report.
214 Go to L<https://bugzilla.redhat.com/> and enter a new bug.
215 Please describe the problem in as much detail as possible.
217 Remember to include the version numbers (step 3) and the debug
218 messages file (step 2).
220 =item 5. Assign the bug to rjones @ redhat.com
222 Assign or reassign the bug to B<rjones @ redhat.com> (without the
223 spaces). You can also send me an email with the bug number if you
224 want a faster response.