set-append and set-kernel parameters are both nullable.

[libguestfs.git] / README

diff --git a/README b/README
index abf058e..d56d21e 100644 (file)
--- a/README
+++ b/README
@@ -19,10 +19,17 @@ Libguestfs is a library that can be linked with C and C++ management
 programs (or management programs written in OCaml, Perl, Python, Ruby, Java
 or Haskell).  You can also use it from shell scripts or the command line.
 
 programs (or management programs written in OCaml, Perl, Python, Ruby, Java
 or Haskell).  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:
+Libguestfs was written by Richard W.M. Jones (rjones@redhat.com) and
+hacked on by lots of other people.  For discussion, development,
+patches, etc. please use the mailing list:

 
 

-  https://www.redhat.com/mailman/listinfo/fedora-virt
+  http://www.redhat.com/mailman/listinfo/libguestfs
+
+
+Home page
+----------------------------------------------------------------------
+
+  http://libguestfs.org/

 
 
 Requirements
 
 
 Requirements


@@ -31,19 +38,28 @@ Requirements
 - recent QEMU >= 0.10 with vmchannel support
   http://lists.gnu.org/archive/html/qemu-devel/2009-02/msg01042.html
 
 - recent QEMU >= 0.10 with vmchannel support
   http://lists.gnu.org/archive/html/qemu-devel/2009-02/msg01042.html
 

-- febootstrap >= 1.5
+- febootstrap >= 2.3
+
+- fakeroot
+
+- fakechroot >= 2.9
+
+- XDR, rpcgen (on Linux these are provided by glibc)

 
 

-- XDR, rpcgen
+- squashfs-tools (mksquashfs only)

 
 - (Optional) Augeas (http://augeas.net/)
 
 - perldoc (pod2man, pod2text) to generate the manual pages and
 
 - (Optional) Augeas (http://augeas.net/)
 
 - perldoc (pod2man, pod2text) to generate the manual pages and

-other documentation.
+  other documentation.

 
 - (Optional) Readline to have nicer command-line editing in guestfish.
 
 
 - (Optional) Readline to have nicer command-line editing in guestfish.
 

+- (Optional) 'reged' program from chntpw to decode Windows registry
+  entries (http://home.eunet.no/~pnordahl/ntpasswd/)
+

 - (Optional) OCaml if you want to rebuild the generated files, and
 - (Optional) OCaml if you want to rebuild the generated files, and

-also to build the OCaml bindings
+  also to build the OCaml bindings

 
 - (Optional) local Fedora mirror
 
 
 - (Optional) local Fedora mirror
 


@@ -58,6 +74,11 @@ bindings
 
 - (Optional) GHC if you want to build the Haskell bindings
 
 
 - (Optional) GHC if you want to build the Haskell bindings
 

+- (Optional) Perl XML::XPath, Sys::Virt modules (for libvirt support
+in virt-inspector).
+
+- (Optional, but highly recommended) perl-libintl for translating perl code.
+

 Running ./configure will check you have all the requirements installed
 on your machine.
 
 Running ./configure will check you have all the requirements installed
 on your machine.
 


@@ -79,17 +100,73 @@ Finally run the tests:
   make check
 
 If everything works, you can install the library and tools by running
   make check
 
 If everything works, you can install the library and tools by running

-these commands as root:
+this command as root:

 
   make install
 
 
 
   make install
 
 

+Fedora
+----------------------------------------------------------------------
+
+We provide packages for Fedora >= 11 in Fedora.  Use those, or build
+from our source RPMs - it's far simpler that way.
+
+You can compile libguestfs on Fedora 10 but you cannot use it with the
+version of qemu in Fedora 10.  You need to compile your own qemu, see
+section 'qemu' below.
+
+
+RHEL / EPEL / CentOS etc
+----------------------------------------------------------------------
+
+We provide packages in EPEL which cover RHEL/CentOS >= 5.  Use those
+or build from our source RPMs.
+
+
+Debian
+----------------------------------------------------------------------
+
+libguestfs is now built as a package in Debian by Guido Gunther and
+the other Debian libvirt maintainers.  See:
+
+http://wiki.debian.org/Teams/DebianLibvirtTeam#Packages
+
+You can build for Debian in two different ways, either building a
+Fedora-based appliance using febootstrap, yum, rpm, fakeroot,
+fakechroot (all packaged in Debian).  However the recommended way is
+to build a Debian-based appliance using debootstrap and debirf.
+
+Both ways are supported by the configure script.
+
+
+qemu
+----------------------------------------------------------------------
+
+By far the most common problem is with broken or incompatible
+qemu releases.
+
+First of all, you need qemu >= 0.10.4, which contains a vmchannel
+implementation.  There are several, conflicting, incompatible things
+called 'vmchannel' which at one time or another have been added or
+proposed for qemu/KVM.  The _only_ one we support is this one:
+
+  http://lists.gnu.org/archive/html/qemu-devel/2009-02/msg01042.html
+
+Secondly, 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.
+
+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.
+
+

 Note on using KVM
 ----------------------------------------------------------------------
 
 Note on using KVM
 ----------------------------------------------------------------------
 

-If you are using x86-64, then 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.
+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.

 
 You may also need to enable KVM support for non-root users, by following
 these instructions:
 
 You may also need to enable KVM support for non-root users, by following
 these instructions:


@@ -104,6 +181,62 @@ On some systems, the chmod will not survive a reboot, and you will
 need to make edits to the udev configuration.
 
 
 need to make edits to the udev configuration.
 
 

+Supermin appliance
+----------------------------------------------------------------------
+
+If you configure with --enable-supermin then we will build a supermin
+appliance (supermin = super-minimized).  This is a very specialized
+appliance which is built on-the-fly at runtime (specifically, when you
+call guestfs_launch).
+
+The normal appliance is a self-contained Linux operating system, based
+on the Fedora/RHEL/CentOS Linux distro.  So it contains a complete
+copy of all the libraries and programs needed, like kernel, libc,
+bash, coreutils etc etc.
+
+The supermin appliance removes the kernel and all the executable
+libraries and programs from the appliance.  That just leaves a
+skeleton of config files and some data files, which is obviously
+massively smaller than the normal appliance.  At runtime we rebuild
+the appliance on-the-fly from the libraries and programs on the host
+(eg. pulling in the real /lib/libc.so, the real /bin/bash etc.)
+
+Although this process of rebuilding the appliance each time sounds
+slow, it turns out to be faster than using the prebuilt appliance.
+(Most of the saving comes from not compressing the appliance - it
+transpires that decompressing the appliance is the slowest part of the
+whole boot sequence).  On my machine, a new appliance can be built in
+under a fifth of a second, and the boot time is several seconds
+shorter.
+
+The big advantage of the supermin appliance for distributions like
+Fedora is that it gets security fixes automatically from the host, so
+there is no need to rebuild the whole of libguestfs for a security
+update in some underlying library.
+
+There are several DISADVANTAGES:
+
+It won't work at all except in very narrow, controlled cases like the
+Fedora packaging case.  We control the dependencies of the libguestfs
+RPM tightly to ensure that the required binaries are actually present
+on the host.
+
+Furthermore there are certain unlikely changes in the packages on the
+host which could break a supermin appliance, eg. an updated library
+which depends on an additional data file.
+
+Also supermin appliances are subjected to changes in the host kernel
+which might break compatibility with qemu -- these are, of course,
+real bugs in any case.
+
+Lastly, supermin appliances really can't be moved between branches of
+distributions (eg. built on Fedora 12 and moved to Fedora 10) because
+they are not self-contained and they rely on certain libraries being
+around.  You shouldn't do this anyway.
+
+Use supermin appliances with caution.
+
+

 Notes on cross-architecture support
 ----------------------------------------------------------------------
 
 Notes on cross-architecture support
 ----------------------------------------------------------------------
 


@@ -122,10 +255,11 @@ that in future we will be able to cross-compile the daemon.
 Mirroring tip
 ----------------------------------------------------------------------
 
 Mirroring tip
 ----------------------------------------------------------------------
 

-Having a local Fedora mirror makes a massive difference to the time it
-takes to build and rebuild initramfs images.
+On my machines I can usually rebuild the appliance in around 3
+minutes.  If it takes much longer for you, use a local Fedora mirror
+or squid.

 
 

-Failing that, use squid to cache yum downloads, but read this first:
+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,
 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,


@@ -137,8 +271,24 @@ 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
 
 limits:
 http://fedoraproject.org/wiki/Using_Mock_to_test_package_builds#Using_Squid_to_Speed_Up_Mock_package_downloads
 

-IntelligentMirror is another possibility, although I couldn't get it
-to work for me.
+
+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 find or port the following packages
+first:
+
+ - fakeroot
+ - fakechroot
+ - python
+ - rpm-python    http://www.rpm.org/
+ - yum           http://yum.baseurl.org/
+ - febootstrap   http://et.redhat.com/~rjones/febootstrap/

 
 
 Copyright and license information
 
 
 Copyright and license information