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 http://libguestfs.org/
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37 - recent QEMU >= 0.10 with vmchannel support
38 http://lists.gnu.org/archive/html/qemu-devel/2009-02/msg01042.html
46 - XDR, rpcgen (on Linux these are provided by glibc)
48 - squashfs-tools (mksquashfs only)
50 - (Optional) Augeas (http://augeas.net/)
52 - perldoc (pod2man, pod2text) to generate the manual pages and
55 - (Optional) Readline to have nicer command-line editing in guestfish.
57 - (Optional) 'reged' program from chntpw to decode Windows registry
58 entries (http://home.eunet.no/~pnordahl/ntpasswd/)
60 - (Optional) OCaml if you want to rebuild the generated files, and
61 also to build the OCaml bindings
63 - (Optional) local Fedora mirror
65 - (Optional) Perl if you want to build the perl bindings
67 - (Optional) Python if you want to build the python bindings
69 - (Optional) Ruby, rake if you want to build the ruby bindings
71 - (Optional) Java, JNI, jpackage-utils if you want to build the java
74 - (Optional) GHC if you want to build the Haskell bindings
76 Running ./configure will check you have all the requirements installed
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83 Then make the daemon, library and root filesystem:
85 ./configure [--with-mirror=URI]
88 Use the optional --with-mirror parameter to specify the URI of a local
89 Fedora mirror. See the discussion of the MIRROR parameter in the
90 febootstrap(8) manpage.
92 Finally run the tests:
96 If everything works, you can install the library and tools by running
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105 We provide packages for Fedora >= 11 in Fedora. Use those, or build
106 from our source RPMs - it's far simpler that way.
108 You can compile libguestfs on Fedora 10 but you cannot use it with the
109 version of qemu in Fedora 10. You need to compile your own qemu, see
110 section 'qemu' below.
113 RHEL / EPEL / CentOS etc
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116 We provide packages in EPEL which cover RHEL/CentOS >= 5. Use those
117 or build from our source RPMs.
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123 libguestfs should build and run on Debian. At the moment we don't
124 provide Debian packages, and because of the appliance it's rather
125 complicated to provide a package which could be accepted into the
126 Debian repositories. Want to help? Please contact us.
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132 By far the most common problem is with broken or incompatible
135 First of all, you need qemu >= 0.10.4, which contains a vmchannel
136 implementation. There are several, conflicting, incompatible things
137 called 'vmchannel' which at one time or another have been added or
138 proposed for qemu/KVM. The _only_ one we support is this one:
140 http://lists.gnu.org/archive/html/qemu-devel/2009-02/msg01042.html
142 Secondly, different versions of qemu have problems booting the
143 appliance for different reasons. This varies between versions of
144 qemu, and Linux distributions which add their own patches.
146 If you find a problem, you could try using your own qemu built from
147 source (qemu is very easy to build from source), with a 'qemu
148 wrapper'. Qemu wrappers are described in the guestfs(3) manpage.
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154 By default the configure script will look for qemu-kvm (KVM support).
155 You will need a reasonably recent processor for this to work. KVM is
156 much faster than using plain Qemu.
158 You may also need to enable KVM support for non-root users, by following
161 http://www.linux-kvm.org/page/FAQ#How_can_I_use_kvm_with_a_non-privileged_user.3F
163 On some systems, this will work too:
167 On some systems, the chmod will not survive a reboot, and you will
168 need to make edits to the udev configuration.
171 Notes on cross-architecture support
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174 At the moment we basically don't support cross-architecture or
175 32-on-64. This limits what is possible for some guests. Filesystem
176 operations and FTP export will work fine, but running commands in
177 guests may not be possible.
179 To enable this requires work for cross-architecture and 32-on-64
180 support in febootstrap, fakeroot and fakechroot.
182 The daemon/ directory contains its own configure script. This is so
183 that in future we will be able to cross-compile the daemon.
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189 On my machines I can usually rebuild the appliance in around 3
190 minutes. If it takes much longer for you, use a local Fedora mirror
193 To use squid to cache yum downloads, read this first:
194 https://lists.dulug.duke.edu/pipermail/yum/2006-August/009041.html
195 (In brief, because yum chooses random mirrors each time, squid doesn't
196 work very well with default yum configuration. To get around this,
197 choose a Fedora mirror which is close to you, set this with
198 './configure --with-mirror=[...]', and then proxy the whole lot
199 through squid by setting http_proxy environment variable).
201 You will also need to substantially increase the squid configuration
203 http://fedoraproject.org/wiki/Using_Mock_to_test_package_builds#Using_Squid_to_Speed_Up_Mock_package_downloads
206 Porting to other Linux distros / non-Linux
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209 libguestfs itself should be fairly portable to other Linux
210 distributions. Non-Linux ports are trickier, but we will accept
211 patches if they aren't too invasive.
213 The main porting issues are with the dependencies needed to build the
214 appliance. You will need to find or port the following packages
220 - rpm-python http://www.rpm.org/
221 - yum http://yum.baseurl.org/
222 - febootstrap http://et.redhat.com/~rjones/febootstrap/
225 Copyright and license information
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228 Copyright (C) 2009 Red Hat Inc.
230 The library is distributed under the LGPLv2+. The programs are
231 distributed under the GPLv2+. Please see the files COPYING and
232 COPYING.LIB for full license information.