1 ganeti-instance-debootstrap
2 ===========================
4 This is a guest OS definition for Ganeti (http://code.google.com/p/ganeti).
5 It will install a minimal version of Debian or Ubuntu via debootstrap (thus it
6 requires network access). This only works if you have a Debian-based node or
7 you have debootstrap installed by hand on another distribution.
12 In order to install this package from source, you need to determine what
13 options ganeti itself has been configured with. If ganeti was built
14 directly from source, then the only place it looks for OS definitions is
15 ``/srv/ganeti/os``, and you need to install the OS under it::
17 ./configure --prefix=/usr --localstatedir=/var \
19 --with-os-dir=/srv/ganeti/os
22 If ganeti was installed from a package, its default OS path should
23 already include /usr/share/ganeti/os, so you can just run::
25 ./configure -prefix=/usr --localstatedir=/var \
29 Note that you need to repeat this procedure on all nodes of the cluster.
31 The actual path that ganeti has been installed with can be determined by
32 looking for a file named _autoconf.py under a ganeti directory in the
33 python modules tree (e.g.
34 ``/usr/lib/python2.4/site-packages/ganeti/_autoconf.py``). In this file,
35 a variable named OS_SEARCH_PATH will list all the directories in which
36 ganeti will look for OS definitions.
38 Configuration of instance creation
39 ----------------------------------
41 Note: the minimum disk size accepted is 256MB, as ``debootstrap``
42 requires disk space both for downloading the packages and installing
45 The kind of instance created can be customized via a settings file. This
46 file is not installed by default, as the instance creation will work
47 without it. The creation scripts will look for it in
48 ``$sysconfdir/default/ganeti-instance-debootstrap``, so if you have run
49 configure with the parameter ``--sysconfdir=/etc``, the final filename
50 will be ``/etc/default/ganeti-instance-debootstrap``.
52 The following settings will be examined in this file (see also the file
53 named 'defaults' in the source distribution for more details):
55 - PROXY: http proxy to use for non-cached installs
56 - MIRROR: the mirror to use if not the default one
57 - ARCH: either i386 or amd64, otherwise your current architecture will
59 - SUITE: the actual OS to be installed; the current default is Debian
60 *lenny*, and you can choose any of the OSes supported deboostrap (on
61 Debian, look into /usr/share/deboostrap/scripts)
62 - EXTRAPKGS: most OSes will need some extra packages installed to make
63 them work nicely under Xen; the example file containts a few
65 - COMPONENTS: if defined, overrides the default debootstrap components
66 ("main"); this can be helpful e.g. by using "main,contrib,nonfree" for
67 Debian, or "main,universe" for Ubuntu
68 - CUSTOMIZE_DIR: a directory containing customization script for the
69 instance. (by default $sysconfdir/ganeti/instance-debootstrap/hooks)
70 See "Customization of the instance" below.
71 - GENERATE_CACHE: if 'yes' (the default), the installation process will
72 save and reuse a cache file to speed reinstalls (located under
73 $localstatedir/cache/ganeti-instance-debootstrap)
74 - CLEAN_CACHE: if empty, the cached files will never be cleaned and thus
75 the installation will definitely need to be updated after install;
76 otherwise, the value of this variable will be taken as the number of
77 days after which to remove the cache file; the default is 14 (two
79 - PARTITION_STYLE: if 'none' the device will be formatted directly, if 'msdos'
80 a partition table will be installed on it. You need to have kpartx installed
81 to use the 'msdos' option. The default is 'msdos' from Ganeti 2.0 onwards,
82 but still 'none' if installing under Ganeti 1.2
84 Note that the settings file is important on the node that the instance
85 is installed on, not the cluster master. This is indeed not a very good
86 model of using this OS but currently the OS interface in ganeti is
89 Customization of the instance
90 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
92 If run-parts is in the os create script, and the CUSTOMIZE_DIR (by
93 default $sysconfdir/ganeti/instance-debootstrap/hooks,
94 /etc/ganeti/instance-debootstrap/hooks if you configured the os with
95 --sysconfdir=/etc) directory exists any executable whose name matches
96 the run-parts execution rules (quoting run-parts(8): the names must
97 consist entirely of upper and lower case letters, digits, underscores,
98 and hyphens) is executed to allow further personalization of the
99 installation. The following environment variables are passed, in
100 addition to the ones ganeti passes to the OS scripts:
102 TARGET: directory in which the filesystem is mounted
103 SUITE: suite installed by debootstrap (eg: lenny)
104 ARCH: target architecture
105 PARTITION_STYLE: style of the disk partitioning (see above)
106 EXTRA_PKGS: extra packages installed by debootstrap
107 BLOCKDEV: ganeti block device
108 FSYSDEV: device in which the filesystem resides (the one mounted in TARGET)
110 The scripts in CUSTOMIZE_DIR can exit with an error code to signal an error in
111 the instance creation, should they fail.
113 The scripts in CUSTOMIZE_DIR should not start any long-term processes or
114 daemons using this directory, otherwise the installation will fail because it
115 won't be able to umount the filesystem from the directory, and hand the
116 instance back to Ganeti.
122 As described above, the install process uses a cache file in order to
123 speed up repeated installs. If you only rarely do installs, this will
124 not matter to you, but if you want to install 10 instances in a row, the
125 difference will be visible.
127 The default settings are to generate a cache, and to clean it up after
130 Note that the cache will use one file per architecture per suite, so if
131 you install multiple suites there might be a non-trivial amount of space
132 used in the cache directory. It is safe to remove manually the files.
134 It is also possible, if done with care, to modify and regenerate the
135 cache file (which is simply a tar archive) in order to preseed your
136 installs with site-specific customizations.
141 The instance is a minimal install:
143 - it has no password for root; simply login at the console
144 - it has no network interfaces defined (besides lo); add your own
145 definitions to /etc/network/interfaces
146 - after configuring the network, it is recommended to run ``apt-get
147 update`` so that signatures for the release files are picked up
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