X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=README;h=bf978ca25bab15786b2b23038ebc2b7e90514dbc;hp=6c9d5ab7905ea746ddf822a6ffa59f26869a6e43;hb=be7cb789069afc93e7c1b0e7a1a9a293dc846d45;hpb=28d760b1542da7ff83b18c4ca60c2d03f327c2f4 diff --git a/README b/README index 6c9d5ab..bf978ca 100644 --- a/README +++ b/README @@ -1,174 +1,267 @@ -libguestfs is a library for accessing and modifying guest disk images. -Amongst the things this is good for: making batch configuration -changes to guests, getting disk used/free statistics (see also: -virt-df), migrating between virtualization systems (see also: -virt-p2v), performing partial backups, performing partial guest -clones, cloning guests and changing registry/UUID/hostname info, and -much else besides. +Libguestfs is tools and a library for accessing and modifying guest +disk images. For more information see the home page: -libguestfs uses Linux kernel and qemu code, and can access any type of -guest filesystem that Linux and qemu can, including but not limited -to: ext2/3/4, btrfs, FAT and NTFS, LVM, many different disk partition -schemes, qcow, qcow2, vmdk. + http://libguestfs.org/ -libguestfs provides ways to enumerate guest storage (eg. partitions, -LVs, what filesystem is in each LV, etc.). It can also run commands -in the context of the guest. Also you can mount guest filesystems on -the host (requires root privs and NFS). +For discussion, development, patches, etc. please use the mailing +list: -libguestfs is a library that can be linked with C and C++ management -programs (or management programs written in other languages, if people -contribute the language bindings). You can also use it from shell -scripts or the command line. - -libguestfs was written by Richard W.M. Jones (rjones@redhat.com). -For discussion please use the fedora-virt mailing list: - - https://www.redhat.com/mailman/listinfo/fedora-virt + http://www.redhat.com/mailman/listinfo/libguestfs Requirements ---------------------------------------------------------------------- -- nfs-utils source, unpacked - http://download.sourceforge.net/nfs +Running ./configure will check you have all the requirements installed +on your machine. + +Fedora/RHEL users: + + A useful tip is to run: + + yum-builddep libguestfs + + which will install all build dependencies automatically. If that is + successful, you don't need to bother with the rest of this section. + +Debian/Ubuntu users: + + Take a look at the debian/control file and install everything listed + in "Build-Depends". If that is successful, you don't need to bother + with the rest of this section. -- Recent QEMU with vmchannel support +The full requirements are described below. -- Compiled Linux kernels for 32 and/or 64 bit (see note below). +For basic functionality and the C tools: -- mkinitrd +- look at appliance/packagelist.in and install as many of the packages + that apply to your distro as possible + +- recent QEMU >= 0.13 (0.14 or later is better) with virtio-serial support + +- kernel >= 2.6.34 with virtio-serial support enabled. + +- virtio-block and virtio-net drivers should be compiled into your + host kernel (strictly speaking this is optional, but you will have + to make complex changes to the ./configure command line to get it + to work if you don't have virtio) + +- febootstrap >= 3.3 (it is best to use the latest version) + + Notes: (1) febootstrap 2.x WILL NOT WORK + (2) febootstrap 3.x is distro-independent, and is required on + Debian and other distros as well as Fedora + +- XDR, rpcgen (on Linux these are provided by glibc) - cpio -- XDR, rpcgen +- gperf -- If you are running a 64 bit or non-x86 machine, see note below. +- pcre (Perl Compatible Regular Expressions C library) -We don't support initramfs at the moment. Patches gratefully -received. +- genisoimage (NOT mkisofs any more) -Running ./configure will check you have all the requirements installed -on your machine. +- hivex >= 1.2.7 (http://libguestfs.org/download) (optional) +- libmagic (the library that corresponds to the 'file' command) (optional) -Building ----------------------------------------------------------------------- +- libvirt (optional) -Unpack nfs-utils source into a directory somewhere, then create a -symlink daemon/nfs-utils to where you unpacked it. For example: +- libxml2 (optional) - pushd daemon - tar zxf /path/to/nfs-utils-1.1.4.tar.gz - ln -s nfs-utils-1.1.4 nfs-utils - popd +- libconfig (optional) -For nfs-utils 1.1.4, you may find that the patch -(nfs-utils-1.1.4-build.patch) helps. +- augeas >= 0.5.0 (http://augeas.net/) (optional) -Then make the library and shell tools: +- Berkeley DB 'db_dump' and 'db_load' utilities + (db4-utils or db4.X-util or similar) (optional) - ./configure - make +- systemtap/DTrace userspace probes (optional) + http://sourceware.org/systemtap/wiki/AddingUserSpaceProbingToApps -Make the daemon and NFS server: - mkdir daemon/build - pushd daemon/build - ../configure - make - popd +- perldoc (pod2man, pod2text, pod2html) to generate the manual pages + and other documentation. -For 64 bit you'll probably want to build the 32 bit daemon and NFS -server too: +- Readline to have nicer command-line editing in guestfish (optional) - mkdir daemon/build-32 - pushd daemon/build-32 - ../configure --enable-32bit - make - popd +- xmllint (part of libxml2) to validate virt-inspector + RELAX NG schema (optional) + +- OCaml if you want to rebuild the generated files, and + also to build the OCaml bindings (optional) + +- po4a for translating manpages and POD files. + This is optional when compiling from the tarball, but mandatory + if you compile from git. + +- getfacl, getfattr libraries and programs (optional) + +To build FUSE support (guestmount): + +- FUSE libraries and kernel module (optional) + +To build language bindings: + +- Perl if you want to build the perl bindings (optional) + +- Python if you want to build the python bindings (optional) + +- Ruby, rake if you want to build the ruby bindings (optional) + +- Java, JNI, jpackage-utils if you want to build the java + bindings (optional) + +- GHC if you want to build the Haskell bindings (optional) + +- PHP, phpize if you want to build the PHP bindings (optional) + +To build the Perl tools: -For complex cross-architecture environments, you may want to build -other versions of the daemon and NFS server as well. See the note -below. +- Perl Sys::Virt module (optional) + +- Perl Win::Hivex module (optional) + +- Perl Pod::Usage module (optional) + +- Perl Test::More module (from perl Test::Simple) (optional) + +- Perl String::ShellQuote module (optional) + +- perl-libintl for translating perl code (optional) + +To run virt-sysprep: + +- virt-sysprep requires FUSE support since it uses guestmount + + +Building +---------------------------------------------------------------------- + +Then make the daemon, library and root filesystem: + + ./configure + make Finally run the tests: make check +There are some extra tests, but these require that you have some +libvirt guests installed, that these guests' disks are accessible by +the current user, and these tests may fail for other reasons which are +not necessarily because of real problems. If you want to run these +extra tests do: + + make extra-tests + If everything works, you can install the library and tools by running -these commands as root: +this command as root: make install - pushd daemon/build - make install - popd - # Repeat for each daemon/build* directory you made above. +You can run guestfish, guestmount and the virt tools without needing +to install, using the "run" script in the top directory. This script +sets up some environment variables. For example: + ./run ./fish/guestfish [usual guestfish args ...] -Note on 64 bit and non-x86 architectures + ./run ./inspector/virt-inspector [usual virt-inspector args ...] + +If you are already in the fish/ subdirectory, then the following +command will also work: + + ../run ./guestfish [...] + +You can also make a symlink (note: NOT a hard link) from your $PATH to +the run script, eg: + + cd ~/bin + ln -s ~/libguestfs/run libguestfs-run + cd ~/libguestfs + libguestfs-run ./inspector/virt-inspector [...] + +You can also run the C programs under valgrind like this: + + ./run valgrind [valgrind opts...] ./cat/virt-cat [virt-cat opts...] + +This also works with sudo (eg. if you need root access for libvirt or +to access a block device): + + sudo ./run ./cat/virt-cat -d LinuxGuest /etc/passwd + + +qemu ---------------------------------------------------------------------- -The library runs the Linux kernel code in QEMU. It also runs a small -control daemon inside QEMU. It might also run an NFS server. It -might also run programs from the guest's disk/environment (if asked to). +By far the most common problem is with broken or incompatible +qemu releases. -This leaves open the question of which QEMU do we run, eg. qemu (the -i386 emulator) or qemu-system-x86_64 or qemu-system-ppc64 or ...? +Different versions of qemu have problems booting the appliance for +different reasons. This varies between versions of qemu, and Linux +distributions which add their own patches. -Several factors influence the choice: +If you find a problem, you could try using your own qemu built from +source (qemu is very easy to build from source), with a 'qemu +wrapper'. Qemu wrappers are described in the guestfs(3) manpage. -(a) The host architecture. -(b) The guest architecture. +Note on using KVM +---------------------------------------------------------------------- -(c) What kernel(s) we find at runtime. +By default the configure script will look for qemu-kvm (KVM support). +You will need a reasonably recent processor for this to work. KVM is +much faster than using plain Qemu. -(d) What compiler(s) we find at configure time. +You may also need to enable KVM support for non-root users, by following +these instructions: -(e) In general, we would prefer to run a 32 bit kernel over a 64 bit -kernel, because that reduces the amount of system memory we have to -give to qemu significantly, and makes libguestfs smaller, faster and -use less memory. + http://www.linux-kvm.org/page/FAQ#How_can_I_use_kvm_with_a_non-privileged_user.3F -For example, if (a) the host is x86-64, then it might be running a -mixture of (b) i386 and x86-64 guests. Disk formats are stable, even -across 32 and 64 bit and endianness changes, so it doesn't really -matter what kernel we use if we just want to access files in the -guest. In the absence of any other factors, we would choose an i386 -kernel and run it in plain 'qemu', because that would use the least -amount of memory. +On some systems, this will work too: -But if we wanted to enable the feature of running a guest program in -an x86-64 guest, then we have to run an x86-64 kernel and -qemu-system-x86_64 (an i386 kernel can't run 64 bit programs). The -same applies if we didn't find a 32 bit kernel at runtime, or if we -couldn't run "gcc -m32" at configure time (because we can't compile -the daemon). + chmod o+rw /dev/kvm -SO: to enable maximum features on 64 bit architectures: +On some systems, the chmod will not survive a reboot, and you will +need to make edits to the udev configuration. -(1) Ensure that "gcc -m32" can create usable binaries. -(2) Provide 32 and 64 bit kernels binaries at runtime. +Mirroring tip +---------------------------------------------------------------------- -If you have a really weird environment, eg. you want to run programs -inside PPC64 guests on your MIPS machine, then: +On my machines I can usually rebuild the appliance in around 3 +minutes. If it takes much longer for you, use a local distro mirror +or squid. -(3) Provide gcc cross-compiler and glibc for each architecture, and -cross-compile the daemon and NFS server: +To use squid to cache yum downloads, read this first: +https://lists.dulug.duke.edu/pipermail/yum/2006-August/009041.html +(In brief, because yum chooses random mirrors each time, squid doesn't +work very well with default yum configuration. To get around this, +choose a Fedora mirror which is close to you, set this with +'./configure --with-mirror=[...]', and then proxy the whole lot +through squid by setting http_proxy environment variable). - mkdir daemon/build-ppc64 - pushd daemon/build-ppc64 - ../configure --host=ppc64-gnu-linux - make - popd +You will also need to substantially increase the squid configuration +limits: +http://fedoraproject.org/wiki/Using_Mock_to_test_package_builds#Using_Squid_to_Speed_Up_Mock_package_downloads + + +Porting to other Linux distros / non-Linux +---------------------------------------------------------------------- + +libguestfs itself should be fairly portable to other Linux +distributions. Non-Linux ports are trickier, but we will accept +patches if they aren't too invasive. + +The main porting issues are with the dependencies needed to build the +appliance. You will need to port the febootstrap first +(http://people.redhat.com/~rjones/febootstrap/). Copyright and license information ---------------------------------------------------------------------- -Copyright (C) 2009 Red Hat Inc. +Copyright (C) 2009-2011 Red Hat Inc. The library is distributed under the LGPLv2+. The programs are distributed under the GPLv2+. Please see the files COPYING and