1 Libguestfs is a library for accessing and modifying guest disk images.
2 Amongst the things this is good for: making batch configuration
3 changes to guests, getting disk used/free statistics (see also:
4 virt-df), migrating between virtualization systems (see also:
5 virt-p2v), performing partial backups, performing partial guest
6 clones, cloning guests and changing registry/UUID/hostname info, and
9 Libguestfs uses Linux kernel and qemu code, and can access any type of
10 guest filesystem that Linux and qemu can, including but not limited
11 to: ext2/3/4, btrfs, FAT and NTFS, LVM, many different disk partition
12 schemes, qcow, qcow2, vmdk.
14 Libguestfs provides ways to enumerate guest storage (eg. partitions,
15 LVs, what filesystem is in each LV, etc.). It can also run commands
16 in the context of the guest. Also you can access filesystems over FTP.
18 Libguestfs is a library that can be linked with C and C++ management
19 programs (or management programs written in OCaml, Perl, Python, Ruby, Java
20 or Haskell). You can also use it from shell scripts or the command line.
22 Libguestfs was written by Richard W.M. Jones (rjones@redhat.com).
23 For discussion please use the fedora-virt mailing list:
25 https://www.redhat.com/mailman/listinfo/fedora-virt
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31 - recent QEMU >= 0.10 with vmchannel support
32 http://lists.gnu.org/archive/html/qemu-devel/2009-02/msg01042.html
40 - XDR, rpcgen (on Linux these are provided by glibc)
42 - squashfs-tools (mksquashfs only)
44 - (Optional) Augeas (http://augeas.net/)
46 - perldoc (pod2man, pod2text) to generate the manual pages and
49 - (Optional) Readline to have nicer command-line editing in guestfish.
51 - (Optional) 'reged' program from chntpw to decode Windows registry
52 entries (http://home.eunet.no/~pnordahl/ntpasswd/)
54 - (Optional) OCaml if you want to rebuild the generated files, and
55 also to build the OCaml bindings
57 - (Optional) local Fedora mirror
59 - (Optional) Perl if you want to build the perl bindings
61 - (Optional) Python if you want to build the python bindings
63 - (Optional) Ruby, rake if you want to build the ruby bindings
65 - (Optional) Java, JNI, jpackage-utils if you want to build the java
68 - (Optional) GHC if you want to build the Haskell bindings
70 Running ./configure will check you have all the requirements installed
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77 Then make the daemon, library and root filesystem:
79 ./configure [--with-mirror=URI]
82 Use the optional --with-mirror parameter to specify the URI of a local
83 Fedora mirror. See the discussion of the MIRROR parameter in the
84 febootstrap(8) manpage.
86 Finally run the tests:
90 If everything works, you can install the library and tools by running
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99 We provide packages for Fedora >= 11 in Fedora. Use those, or build
100 from our source RPMs - it's far simpler that way.
102 You can compile libguestfs on Fedora 10 but you cannot use it with the
103 version of qemu in Fedora 10. You need to compile your own qemu, see
104 section 'qemu' below.
107 RHEL / EPEL / CentOS etc
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110 We provide packages in EPEL which cover RHEL/CentOS >= 5. Use those
111 or build from our source RPMs.
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117 libguestfs should build and run on Debian. At the moment we don't
118 provide Debian packages, and because of the appliance it's rather
119 complicated to provide a package which could be accepted into the
120 Debian repositories. Want to help? Please contact us.
124 ----------------------------------------------------------------------
126 By far the most common problem is with broken or incompatible
129 First of all, you need qemu >= 0.10.4, which contains a vmchannel
130 implementation. There are several, conflicting, incompatible things
131 called 'vmchannel' which at one time or another have been added or
132 proposed for qemu/KVM. The _only_ one we support is this one:
134 http://lists.gnu.org/archive/html/qemu-devel/2009-02/msg01042.html
136 Secondly, different versions of qemu have problems booting the
137 appliance for different reasons. This varies between versions of
138 qemu, and Linux distributions which add their own patches.
140 If you find a problem, you could try using your own qemu built from
141 source (qemu is very easy to build from source), with a 'qemu
142 wrapper'. Qemu wrappers are described in the guestfs(3) manpage.
146 ----------------------------------------------------------------------
148 By default the configure script will look for qemu-kvm (KVM support).
149 You will need a reasonably recent processor for this to work. KVM is
150 much faster than using plain Qemu.
152 You may also need to enable KVM support for non-root users, by following
155 http://www.linux-kvm.org/page/FAQ#How_can_I_use_kvm_with_a_non-privileged_user.3F
157 On some systems, this will work too:
161 On some systems, the chmod will not survive a reboot, and you will
162 need to make edits to the udev configuration.
165 Notes on cross-architecture support
166 ----------------------------------------------------------------------
168 At the moment we basically don't support cross-architecture or
169 32-on-64. This limits what is possible for some guests. Filesystem
170 operations and FTP export will work fine, but running commands in
171 guests may not be possible.
173 To enable this requires work for cross-architecture and 32-on-64
174 support in febootstrap, fakeroot and fakechroot.
176 The daemon/ directory contains its own configure script. This is so
177 that in future we will be able to cross-compile the daemon.
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183 On my machines I can usually rebuild the appliance in around 3
184 minutes. If it takes much longer for you, use a local Fedora mirror
187 To use squid to cache yum downloads, read this first:
188 https://lists.dulug.duke.edu/pipermail/yum/2006-August/009041.html
189 (In brief, because yum chooses random mirrors each time, squid doesn't
190 work very well with default yum configuration. To get around this,
191 choose a Fedora mirror which is close to you, set this with
192 './configure --with-mirror=[...]', and then proxy the whole lot
193 through squid by setting http_proxy environment variable).
195 You will also need to substantially increase the squid configuration
197 http://fedoraproject.org/wiki/Using_Mock_to_test_package_builds#Using_Squid_to_Speed_Up_Mock_package_downloads
200 Porting to other Linux distros / non-Linux
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203 libguestfs itself should be fairly portable to other Linux
204 distributions. Non-Linux ports are trickier, but we will accept
205 patches if they aren't too invasive.
207 The main porting issues are with the dependencies needed to build the
208 appliance. You will need to find or port the following packages
214 - rpm-python http://www.rpm.org/
215 - yum http://yum.baseurl.org/
216 - febootstrap http://et.redhat.com/~rjones/febootstrap/
219 Copyright and license information
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222 Copyright (C) 2009 Red Hat Inc.
224 The library is distributed under the LGPLv2+. The programs are
225 distributed under the GPLv2+. Please see the files COPYING and
226 COPYING.LIB for full license information.