1 Ganeti installation tutorial
2 ============================
4 Documents Ganeti version |version|
8 .. highlight:: shell-example
13 Ganeti is a cluster virtualization management system based on Xen or
14 KVM. This document explains how to bootstrap a Ganeti node (Xen *dom0*,
15 the host Linux system for KVM), create a running cluster and install
16 virtual instances (Xen *domUs*, KVM guests). You need to repeat most of
17 the steps in this document for every node you want to install, but of
18 course we recommend creating some semi-automatic procedure if you plan
19 to deploy Ganeti on a medium/large scale.
21 A basic Ganeti terminology glossary is provided in the introductory
22 section of the :doc:`admin`. Please refer to that document if you are
23 uncertain about the terms we are using.
25 Ganeti has been developed for Linux and should be distribution-agnostic.
26 This documentation will use Debian Squeeze as an example system but the
27 examples can be translated to any other distribution. You are expected
28 to be familiar with your distribution, its package management system,
29 and Xen or KVM before trying to use Ganeti.
31 This document is divided into two main sections:
33 - Installation of the base system and base components
35 - Configuration of the environment for Ganeti
37 Each of these is divided into sub-sections. While a full Ganeti system
38 will need all of the steps specified, some are not strictly required for
39 every environment. Which ones they are, and why, is specified in the
40 corresponding sections.
42 Installing the base system and base components
43 ----------------------------------------------
48 Any system supported by your Linux distribution is fine. 64-bit systems
49 are better as they can support more memory.
51 Any disk drive recognized by Linux (``IDE``/``SCSI``/``SATA``/etc.) is
52 supported in Ganeti. Note that no shared storage (e.g. ``SAN``) is
53 needed to get high-availability features (but of course, one can be used
54 to store the images). Whilte it is highly recommended to use more than
55 one disk drive in order to improve speed, Ganeti also works with one
58 Installing the base system
59 ++++++++++++++++++++++++++
61 **Mandatory** on all nodes.
63 It is advised to start with a clean, minimal install of the operating
64 system. The only requirement you need to be aware of at this stage is to
65 partition leaving enough space for a big (**minimum** 20GiB) LVM volume
66 group which will then host your instance filesystems, if you want to use
67 all Ganeti features. The volume group name Ganeti uses (by default) is
70 You can also use file-based storage only, without LVM, but this setup is
71 not detailed in this document.
73 If you choose to use RBD-based instances, there's no need for LVM
74 provisioning. However, this feature is experimental, and is not yet
75 recommended for production clusters.
77 While you can use an existing system, please note that the Ganeti
78 installation is intrusive in terms of changes to the system
79 configuration, and it's best to use a newly-installed system without
82 Also, for best results, it's advised that the nodes have as much as
83 possible the same hardware and software configuration. This will make
84 administration much easier.
89 Note that Ganeti requires the hostnames of the systems (i.e. what the
90 ``hostname`` command outputs to be a fully-qualified name, not a short
91 name. In other words, you should use *node1.example.com* as a hostname
94 .. admonition:: Debian
96 Debian usually configures the hostname differently than you need it
97 for Ganeti. For example, this is what it puts in ``/etc/hosts`` in
101 127.0.1.1 node1.example.com node1
103 but for Ganeti you need to have::
106 192.0.2.1 node1.example.com node1
108 replacing ``192.0.2.1`` with your node's address. Also, the file
109 ``/etc/hostname`` which configures the hostname of the system
110 should contain ``node1.example.com`` and not just ``node1`` (you
111 need to run the command ``/etc/init.d/hostname.sh start`` after
114 .. admonition:: Why a fully qualified host name
116 Although most distributions use only the short name in the
117 /etc/hostname file, we still think Ganeti nodes should use the full
118 name. The reason for this is that calling 'hostname --fqdn' requires
119 the resolver library to work and is a 'guess' via heuristics at what
120 is your domain name. Since Ganeti can be used among other things to
121 host DNS servers, we don't want to depend on them as much as
122 possible, and we'd rather have the uname() syscall return the full
125 We haven't ever found any breakage in using a full hostname on a
126 Linux system, and anyway we recommend to have only a minimal
127 installation on Ganeti nodes, and to use instances (or other
128 dedicated machines) to run the rest of your network services. By
129 doing this you can change the /etc/hostname file to contain an FQDN
130 without the fear of breaking anything unrelated.
133 Installing The Hypervisor
134 +++++++++++++++++++++++++
136 **Mandatory** on all nodes.
138 While Ganeti is developed with the ability to modularly run on different
139 virtualization environments in mind the only two currently useable on a
140 live system are Xen and KVM. Supported Xen versions are: 3.0.3 and later
141 3.x versions, and 4.x (tested up to 4.1). Supported KVM versions are 72
144 Please follow your distribution's recommended way to install and set up
145 Xen, or install Xen from the upstream source, if you wish, following
146 their manual. For KVM, make sure you have a KVM-enabled kernel and the
149 After installing Xen, you need to reboot into your new system. On some
150 distributions this might involve configuring GRUB appropriately, whereas
151 others will configure it automatically when you install the respective
152 kernels. For KVM no reboot should be necessary.
154 .. admonition:: Xen on Debian
156 Under Debian you can install the relevant ``xen-linux-system``
157 package, which will pull in both the hypervisor and the relevant
158 kernel. Also, if you are installing a 32-bit system, you should
159 install the ``libc6-xen`` package (run ``apt-get install
165 It's recommended that dom0 is restricted to a low amount of memory
166 (512MiB or 1GiB is reasonable) and that memory ballooning is disabled in
167 the file ``/etc/xen/xend-config.sxp`` by setting the value
168 ``dom0-min-mem`` to 0, like this::
172 For optimum performance when running both CPU and I/O intensive
173 instances, it's also recommended that the dom0 is restricted to one CPU
174 only. For example you can add ``dom0_max_vcpus=1,dom0_vcpus_pin`` to your
175 kernels boot command line and set ``dom0-cpus`` in
176 ``/etc/xen/xend-config.sxp`` like this::
180 It is recommended that you disable xen's automatic save of virtual
181 machines at system shutdown and subsequent restore of them at reboot.
182 To obtain this make sure the variable ``XENDOMAINS_SAVE`` in the file
183 ``/etc/default/xendomains`` is set to an empty value.
185 If you want to use live migration make sure you have, in the xen config
186 file, something that allows the nodes to migrate instances between each
191 (xend-relocation-server yes)
192 (xend-relocation-port 8002)
193 (xend-relocation-address '')
194 (xend-relocation-hosts-allow '^192\\.0\\.2\\.[0-9]+$')
197 The second line assumes that the hypervisor parameter
198 ``migration_port`` is set 8002, otherwise modify it to match. The last
199 line assumes that all your nodes have secondary IPs in the
200 192.0.2.0/24 network, adjust it accordingly to your setup.
202 If you want to run HVM instances too with Ganeti and want VNC access to
203 the console of your instances, set the following two entries in
204 ``/etc/xen/xend-config.sxp``:
208 (vnc-listen '0.0.0.0') (vncpasswd '')
210 You need to restart the Xen daemon for these settings to take effect::
212 $ /etc/init.d/xend restart
214 Selecting the instance kernel
215 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
217 After you have installed Xen, you need to tell Ganeti exactly what
218 kernel to use for the instances it will create. This is done by creating
219 a symlink from your actual kernel to ``/boot/vmlinuz-3-xenU``, and one
220 from your initrd to ``/boot/initrd-3-xenU`` [#defkernel]_. Note that
221 if you don't use an initrd for the domU kernel, you don't need to create
224 .. admonition:: Debian
226 After installation of the ``xen-linux-system`` package, you need to
227 run (replace the exact version number with the one you have)::
230 $ ln -s vmlinuz-%2.6.26-1%-xen-amd64 vmlinuz-3-xenU
231 $ ln -s initrd.img-%2.6.26-1%-xen-amd64 initrd-3-xenU
233 By default, the initrd doesn't contain the Xen block drivers needed
234 to mount the root device, so it is recommended to update the initrd
235 by following these two steps:
237 - edit ``/etc/initramfs-tools/modules`` and add ``xen_blkfront``
238 - run ``update-initramfs -u``
243 Recommended on all nodes: DRBD_ is required if you want to use the high
244 availability (HA) features of Ganeti, but optional if you don't require
245 them or only run Ganeti on single-node clusters. You can upgrade a
246 non-HA cluster to an HA one later, but you might need to convert all
247 your instances to DRBD to take advantage of the new features.
249 .. _DRBD: http://www.drbd.org/
251 Supported DRBD versions: 8.0-8.3. It's recommended to have at least
252 version 8.0.12. Note that for version 8.2 and newer it is needed to pass
253 the ``usermode_helper=/bin/true`` parameter to the module, either by
254 configuring ``/etc/modules`` or when inserting it manually.
256 Now the bad news: unless your distribution already provides it
257 installing DRBD might involve recompiling your kernel or anyway fiddling
258 with it. Hopefully at least the Xen-ified kernel source to start from
259 will be provided (if you intend to use Xen).
261 The good news is that you don't need to configure DRBD at all. Ganeti
262 will do it for you for every instance you set up. If you have the DRBD
263 utils installed and the module in your kernel you're fine. Please check
264 that your system is configured to load the module at every boot, and
265 that it passes the following option to the module:
266 ``minor_count=NUMBER``. We recommend that you use 128 as the value of
267 the minor_count - this will allow you to use up to 64 instances in total
268 per node (both primary and secondary, when using only one disk per
269 instance). You can increase the number up to 255 if you need more
273 .. admonition:: Debian
275 On Debian, you can just install (build) the DRBD module with the
276 following commands, making sure you are running the target (Xen or
279 $ apt-get install drbd8-source drbd8-utils
283 Or on newer versions, if the kernel already has modules:
285 $ apt-get install drbd8-utils
287 Then to configure it for Ganeti::
289 $ echo drbd minor_count=128 usermode_helper=/bin/true >> /etc/modules
291 $ modprobe drbd minor_count=128 usermode_helper=/bin/true
293 It is also recommended that you comment out the default resources (if any)
294 in the ``/etc/drbd.conf`` file, so that the init script doesn't try to
295 configure any drbd devices. You can do this by prefixing all
296 *resource* lines in the file with the keyword *skip*, like this:
315 Recommended on all nodes: RBD_ is required if you want to create
316 instances with RBD disks residing inside a RADOS cluster (make use of
317 the rbd disk template). RBD-based instances can failover or migrate to
318 any other node in the ganeti cluster, enabling you to exploit of all
319 Ganeti's high availabilily (HA) features.
322 Be careful though: rbd is still experimental! For now it is
323 recommended only for testing purposes. No sensitive data should be
326 .. _RBD: http://ceph.newdream.net/
328 You will need the ``rbd`` and ``libceph`` kernel modules, the RBD/Ceph
329 userspace utils (ceph-common Debian package) and an appropriate
330 Ceph/RADOS configuration file on every VM-capable node.
332 You will also need a working RADOS Cluster accessible by the above
338 You will need a working RADOS Cluster accesible by all VM-capable nodes
339 to use the RBD template. For more information on setting up a RADOS
340 Cluster, refer to the `official docs <http://ceph.newdream.net/>`_.
342 If you want to use a pool for storing RBD disk images other than the
343 default (``rbd``), you should first create the pool in the RADOS
344 Cluster, and then set the corresponding rbd disk parameter named
350 Unless your distribution already provides it, you might need to compile
351 the ``rbd`` and ``libceph`` modules from source. You will need Linux
352 Kernel 3.2 or above for the kernel modules. Alternatively you will have
353 to build them as external modules (from Linux Kernel source 3.2 or
354 above), if you want to run a less recent kernel, or your kernel doesn't
360 The RBD template has been tested with ``ceph-common`` v0.38 and
361 above. We recommend using the latest version of ``ceph-common``.
363 .. admonition:: Debian
365 On Debian, you can just install the RBD/Ceph userspace utils with
366 the following command::
368 $ apt-get install ceph-common
373 You should also provide an appropriate configuration file
374 (``ceph.conf``) in ``/etc/ceph``. For the rbd userspace utils, you'll
375 only need to specify the IP addresses of the RADOS Cluster monitors.
377 .. admonition:: ceph.conf
379 Sample configuration file:
384 host = example_monitor_host1
385 mon addr = 1.2.3.4:6789
387 host = example_monitor_host2
388 mon addr = 1.2.3.5:6789
390 host = example_monitor_host3
391 mon addr = 1.2.3.6:6789
393 For more information, please see the `Ceph Docs
394 <http://ceph.newdream.net/docs/latest/>`_
396 Other required software
397 +++++++++++++++++++++++
399 Please install all software requirements mentioned in :doc:`install-quick`.
400 If you want to build Ganeti from source, don't forget to follow the steps
401 required for that as well.
403 Setting up the environment for Ganeti
404 -------------------------------------
406 Configuring the network
407 +++++++++++++++++++++++
409 **Mandatory** on all nodes.
411 You can run Ganeti either in "bridged mode", "routed mode" or
412 "openvswitch mode". In bridged mode, the default, the instances network
413 interfaces will be attached to a software bridge running in dom0. Xen by
414 default creates such a bridge at startup, but your distribution might
415 have a different way to do things, and you'll definitely need to
416 manually set it up under KVM.
418 Beware that the default name Ganeti uses is ``xen-br0`` (which was used
419 in Xen 2.0) while Xen 3.0 uses ``xenbr0`` by default. See the
420 `Initializing the cluster`_ section to learn how to choose a different
421 bridge, or not to use one at all and use "routed mode".
423 In order to use "routed mode" under Xen, you'll need to change the
424 relevant parameters in the Xen config file. Under KVM instead, no config
425 change is necessary, but you still need to set up your network
426 interfaces correctly.
428 By default, under KVM, the "link" parameter you specify per-nic will
429 represent, if non-empty, a different routing table name or number to use
430 for your instances. This allows isolation between different instance
431 groups, and different routing policies between node traffic and instance
434 You will need to configure your routing table basic routes and rules
435 outside of ganeti. The vif scripts will only add /32 routes to your
436 instances, through their interface, in the table you specified (under
437 KVM, and in the main table under Xen).
439 Also for "openvswitch mode" under Xen a custom network script is needed.
440 Under KVM everything should work, but you'll need to configure your
441 switches outside of Ganeti (as for bridges).
443 .. admonition:: Bridging issues with certain kernels
445 Some kernel versions (e.g. 2.6.32) have an issue where the bridge
446 will automatically change its ``MAC`` address to the lower-numbered
447 slave on port addition and removal. This means that, depending on
448 the ``MAC`` address of the actual NIC on the node and the addresses
449 of the instances, it could be that starting, stopping or migrating
450 instances will lead to timeouts due to the address of the bridge
451 (and thus node itself) changing.
453 To prevent this, it's enough to set the bridge manually to a
454 specific ``MAC`` address, which will disable this automatic address
455 change. In Debian, this can be done as follows in the bridge
456 configuration snippet::
458 up ip link set addr $(cat /sys/class/net/$IFACE/address) dev $IFACE
460 which will "set" the bridge address to the initial one, disallowing
463 .. admonition:: Bridging under Debian
465 The recommended way to configure the Xen bridge is to edit your
466 ``/etc/network/interfaces`` file and substitute your normal
467 Ethernet stanza with the following snippet::
470 iface xen-br0 inet static
471 address %YOUR_IP_ADDRESS%
472 netmask %YOUR_NETMASK%
473 network %YOUR_NETWORK%
474 broadcast %YOUR_BROADCAST_ADDRESS%
475 gateway %YOUR_GATEWAY%
479 # example for setting manually the bridge address to the eth0 NIC
480 up ip link set addr $(cat /sys/class/net/eth0/address) dev $IFACE
482 The following commands need to be executed on the local console::
487 To check if the bridge is setup, use the ``ip`` and ``brctl show``
491 9: xen-br0: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qdisc noqueue
492 link/ether 00:20:fc:1e:d5:5d brd ff:ff:ff:ff:ff:ff
493 inet 10.1.1.200/24 brd 10.1.1.255 scope global xen-br0
494 inet6 fe80::220:fcff:fe1e:d55d/64 scope link
495 valid_lft forever preferred_lft forever
498 bridge name bridge id STP enabled interfaces
499 xen-br0 8000.0020fc1ed55d no eth0
501 .. _configure-lvm-label:
506 **Mandatory** on all nodes.
508 The volume group is required to be at least 20GiB.
510 If you haven't configured your LVM volume group at install time you need
511 to do it before trying to initialize the Ganeti cluster. This is done by
512 formatting the devices/partitions you want to use for it and then adding
513 them to the relevant volume group::
515 $ pvcreate /dev/%sda3%
516 $ vgcreate xenvg /dev/%sda3%
520 $ pvcreate /dev/%sdb1%
521 $ pvcreate /dev/%sdc1%
522 $ vgcreate xenvg /dev/%sdb1% /dev/%sdc1%
524 If you want to add a device later you can do so with the *vgextend*
527 $ pvcreate /dev/%sdd1%
528 $ vgextend xenvg /dev/%sdd1%
530 Optional: it is recommended to configure LVM not to scan the DRBD
531 devices for physical volumes. This can be accomplished by editing
532 ``/etc/lvm/lvm.conf`` and adding the ``/dev/drbd[0-9]+`` regular
533 expression to the ``filter`` variable, like this:
537 filter = ["r|/dev/cdrom|", "r|/dev/drbd[0-9]+|" ]
539 Note that with Ganeti a helper script is provided - ``lvmstrap`` which
540 will erase and configure as LVM any not in-use disk on your system. This
541 is dangerous and it's recommended to read its ``--help`` output if you
547 **Mandatory** on all nodes.
549 It's now time to install the Ganeti software itself. Download the
550 source from the project page at `<http://code.google.com/p/ganeti/>`_,
551 and install it (replace 2.6.0 with the latest version)::
553 $ tar xvzf ganeti-%2.6.0%.tar.gz
555 $ ./configure --localstatedir=/var --sysconfdir=/etc
558 $ mkdir /srv/ganeti/ /srv/ganeti/os /srv/ganeti/export
560 You also need to copy the file ``doc/examples/ganeti.initd`` from the
561 source archive to ``/etc/init.d/ganeti`` and register it with your
562 distribution's startup scripts, for example in Debian::
564 $ chmod +x /etc/init.d/ganeti
565 $ update-rc.d ganeti defaults 20 80
567 In order to automatically restart failed instances, you need to setup a
568 cron job run the *ganeti-watcher* command. A sample cron file is
569 provided in the source at ``doc/examples/ganeti.cron`` and you can copy
570 that (eventually altering the path) to ``/etc/cron.d/ganeti``. Finally,
571 a sample logrotate snippet is provided in the source at
572 ``doc/examples/ganeti.logrotate`` and you can copy it to
573 ``/etc/logrotate.d/ganeti`` to have Ganeti's logs rotated automatically.
578 The above ``make install`` invocation, or installing via your
579 distribution mechanisms, will install on the system:
581 - a set of python libraries under the *ganeti* namespace (depending on
582 the python version this can be located in either
583 ``lib/python-$ver/site-packages`` or various other locations)
584 - a set of programs under ``/usr/local/sbin`` or ``/usr/sbin``
585 - if the htools component was enabled, a set of programs under
586 ``/usr/local/bin`` or ``/usr/bin/``
587 - man pages for the above programs
588 - a set of tools under the ``lib/ganeti/tools`` directory
589 - an example iallocator script (see the admin guide for details) under
590 ``lib/ganeti/iallocators``
591 - a cron job that is needed for cluster maintenance
592 - an init script for automatic startup of Ganeti daemons
593 - provided but not installed automatically by ``make install`` is a bash
594 completion script that hopefully will ease working with the many
597 Installing the Operating System support packages
598 ++++++++++++++++++++++++++++++++++++++++++++++++
600 **Mandatory** on all nodes.
602 To be able to install instances you need to have an Operating System
603 installation script. An example OS that works under Debian and can
604 install Debian and Ubuntu instace OSes is provided on the project web
605 site. Download it from the project page and follow the instructions in
606 the ``README`` file. Here is the installation procedure (replace 0.12
607 with the latest version that is compatible with your ganeti version)::
610 $ wget http://ganeti.googlecode.com/files/ganeti-instance-debootstrap-%0.12%.tar.gz
611 $ tar xzf ganeti-instance-debootstrap-%0.12%.tar.gz
612 $ cd ganeti-instance-debootstrap-%0.12%
613 $ ./configure --with-os-dir=/srv/ganeti/os
617 In order to use this OS definition, you need to have internet access
618 from your nodes and have the *debootstrap*, *dump* and *restore*
619 commands installed on all nodes. Also, if the OS is configured to
620 partition the instance's disk in
621 ``/etc/default/ganeti-instance-debootstrap``, you will need *kpartx*
624 .. admonition:: Debian
626 Use this command on all nodes to install the required packages::
628 $ apt-get install debootstrap dump kpartx
630 Or alternatively install the OS definition from the Debian package::
632 $ apt-get install ganeti-instance-debootstrap
636 In order for debootstrap instances to be able to shutdown cleanly
637 they must install have basic ACPI support inside the instance. Which
638 packages are needed depend on the exact flavor of Debian or Ubuntu
639 which you're installing, but the example defaults file has a
640 commented out configuration line that works for Debian Lenny and
643 EXTRA_PKGS="acpi-support-base,console-tools,udev"
645 ``kbd`` can be used instead of ``console-tools``, and more packages
646 can be added, of course, if needed.
648 Please refer to the ``README`` file of ``ganeti-instance-debootstrap`` for
649 further documentation.
651 Alternatively, you can create your own OS definitions. See the manpage
652 :manpage:`ganeti-os-interface(7)`.
654 Initializing the cluster
655 ++++++++++++++++++++++++
657 **Mandatory** once per cluster, on the first node.
659 The last step is to initialize the cluster. After you have repeated the
660 above process on all of your nodes and choose one as the master. Make sure
661 there is a SSH key pair on the master node (optionally generating one using
662 ``ssh-keygen``). Finally execute::
664 $ gnt-cluster init %CLUSTERNAME%
666 The *CLUSTERNAME* is a hostname, which must be resolvable (e.g. it must
667 exist in DNS or in ``/etc/hosts``) by all the nodes in the cluster. You
668 must choose a name different from any of the nodes names for a
669 multi-node cluster. In general the best choice is to have a unique name
670 for a cluster, even if it consists of only one machine, as you will be
671 able to expand it later without any problems. Please note that the
672 hostname used for this must resolve to an IP address reserved
673 **exclusively** for this purpose, and cannot be the name of the first
676 If you want to use a bridge which is not ``xen-br0``, or no bridge at
677 all, change it with the ``--nic-parameters`` option. For example to
678 bridge on br0 you can add::
680 --nic-parameters link=br0
682 Or to not bridge at all, and use a separate routing table::
684 --nic-parameters mode=routed,link=100
686 If you don't have a ``xen-br0`` interface you also have to specify a
687 different network interface which will get the cluster IP, on the master
688 node, by using the ``--master-netdev <device>`` option.
690 You can use a different name than ``xenvg`` for the volume group (but
691 note that the name must be identical on all nodes). In this case you
692 need to specify it by passing the *--vg-name <VGNAME>* option to
693 ``gnt-cluster init``.
695 To set up the cluster as an Xen HVM cluster, use the
696 ``--enabled-hypervisors=xen-hvm`` option to enable the HVM hypervisor
697 (you can also add ``,xen-pvm`` to enable the PVM one too). You will also
698 need to create the VNC cluster password file
699 ``/etc/ganeti/vnc-cluster-password`` which contains one line with the
700 default VNC password for the cluster.
702 To setup the cluster for KVM-only usage (KVM and Xen cannot be mixed),
703 pass ``--enabled-hypervisors=kvm`` to the init command.
705 You can also invoke the command with the ``--help`` option in order to
706 see all the possibilities.
708 Hypervisor/Network/Cluster parameters
709 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
711 Please note that the default hypervisor/network/cluster parameters may
712 not be the correct one for your environment. Carefully check them, and
713 change them either at cluster init time, or later with ``gnt-cluster
716 Your instance types, networking environment, hypervisor type and version
717 may all affect what kind of parameters should be used on your cluster.
721 Instances are by default configured to use a host kernel, and to be
722 reached via serial console, which works nice for Linux paravirtualized
723 instances. If you want fully virtualized instances you may want to
724 handle their kernel inside the instance, and to use VNC.
726 Some versions of KVM have a bug that will make an instance hang when
727 configured to use the serial console (which is the default) unless a
728 connection is made to it within about 2 seconds of the instance's
729 startup. For such case it's recommended to disable the
730 ``serial_console`` option.
733 Joining the nodes to the cluster
734 ++++++++++++++++++++++++++++++++
736 **Mandatory** for all the other nodes.
738 After you have initialized your cluster you need to join the other nodes
739 to it. You can do so by executing the following command on the master
742 $ gnt-node add %NODENAME%
744 Separate replication network
745 ++++++++++++++++++++++++++++
749 Ganeti uses DRBD to mirror the disk of the virtual instances between
750 nodes. To use a dedicated network interface for this (in order to
751 improve performance or to enhance security) you need to configure an
752 additional interface for each node. Use the *-s* option with
753 ``gnt-cluster init`` and ``gnt-node add`` to specify the IP address of
754 this secondary interface to use for each node. Note that if you
755 specified this option at cluster setup time, you must afterwards use it
756 for every node add operation.
761 Execute the ``gnt-node list`` command to see all nodes in the cluster::
764 Node DTotal DFree MTotal MNode MFree Pinst Sinst
765 node1.example.com 197404 197404 2047 1896 125 0 0
767 The above shows a couple of things:
769 - The various Ganeti daemons can talk to each other
770 - Ganeti can examine the storage of the node (DTotal/DFree)
771 - Ganeti can talk to the selected hypervisor (MTotal/MNode/MFree)
776 With Ganeti a tool called :command:`burnin` is provided that can test
777 most of the Ganeti functionality. The tool is installed under the
778 ``lib/ganeti/tools`` directory (either under ``/usr`` or ``/usr/local``
779 based on the installation method). See more details under
785 You can now proceed either to the :doc:`admin`, or read the manpages of
786 the various commands (:manpage:`ganeti(7)`, :manpage:`gnt-cluster(8)`,
787 :manpage:`gnt-node(8)`, :manpage:`gnt-instance(8)`,
788 :manpage:`gnt-job(8)`).
790 .. rubric:: Footnotes
792 .. [#defkernel] The kernel and initrd paths can be changed at either
793 cluster level (which changes the default for all instances) or at
796 .. vim: set textwidth=72 :