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gnt-cluster(8) Ganeti | Version @GANETI_VERSION@
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================================================
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Name
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----
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gnt-cluster - Ganeti administration, cluster-wide
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Synopsis
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--------
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**gnt-cluster** {command} [arguments...]
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DESCRIPTION
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-----------
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The **gnt-cluster** is used for cluster-wide administration in the
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Ganeti system.
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COMMANDS
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--------
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ADD-TAGS
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~~~~~~~~
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**add-tags** [--from *file*] {*tag*...}
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Add tags to the cluster. If any of the tags contains invalid
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characters, the entire operation will abort.
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If the ``--from`` option is given, the list of tags will be
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extended with the contents of that file (each line becomes a tag).
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In this case, there is not need to pass tags on the command line
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(if you do, both sources will be used). A file name of - will be
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interpreted as stdin.
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COMMAND
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~~~~~~~
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**command** [-n *node*] [-g *group*] {*command*}
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Executes a command on all nodes. If the option ``-n`` is not given,
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the command will be executed on all nodes, otherwise it will be
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executed only on the node(s) specified. Use the option multiple
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times for running it on multiple nodes, like::
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    # gnt-cluster command -n node1.example.com -n node2.example.com date
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The ``-g`` option can be used to run a command only on a specific node
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group, e.g.::
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    # gnt-cluster command -g default date
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The command is executed serially on the selected nodes. If the
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master node is present in the list, the command will be executed
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last on the master. Regarding the other nodes, the execution order
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is somewhat alphabetic, so that node2.example.com will be earlier
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than node10.example.com but after node1.example.com.
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So given the node names node1, node2, node3, node10, node11, with
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node3 being the master, the order will be: node1, node2, node10,
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node11, node3.
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The command is constructed by concatenating all other command line
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arguments. For example, to list the contents of the /etc directory
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on all nodes, run::
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    # gnt-cluster command ls -l /etc
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and the command which will be executed will be ``ls -l /etc``.
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COPYFILE
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~~~~~~~~
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| **copyfile** [--use-replication-network] [-n *node*] [-g *group*]
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| {*file*}
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Copies a file to all or to some nodes. The argument specifies the
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source file (on the current system), the ``-n`` argument specifies
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the target node, or nodes if the option is given multiple times. If
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``-n`` is not given at all, the file will be copied to all nodes. The
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``-g`` option can be used to only select nodes in a specific node group.
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Passing the ``--use-replication-network`` option will cause the
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copy to be done over the replication network (only matters if the
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primary/secondary IPs are different). Example::
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    # gnt-cluster -n node1.example.com -n node2.example.com copyfile /tmp/test
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This will copy the file /tmp/test from the current node to the two
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named nodes.
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DESTROY
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~~~~~~~
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**destroy** {--yes-do-it}
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Remove all configuration files related to the cluster, so that a
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**gnt-cluster init** can be done again afterwards.
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Since this is a dangerous command, you are required to pass the
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argument *--yes-do-it.*
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EPO
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~~~
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**epo** [--on] [--groups|--all] [--power-delay] *arguments*
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Performs an emergency power-off on nodes given as arguments. If
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``--groups`` is given, arguments are node groups. If ``--all`` is
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provided, the whole cluster will be shut down.
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The ``--on`` flag recovers the cluster after an emergency power-off.
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When powering on the cluster you can use ``--power-delay`` to define the
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time in seconds (fractions allowed) waited between powering on
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individual nodes.
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Please note that the master node will not be turned down or up
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automatically.  It will just be left in a state, where you can manully
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perform the shutdown of that one node. If the master is in the list of
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affected nodes and this is not a complete cluster emergency power-off
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(e.g. using ``--all``), you're required to do a master failover to
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another node not affected.
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GETMASTER
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~~~~~~~~~
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**getmaster**
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Displays the current master node.
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INFO
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~~~~
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**info** [--roman]
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Shows runtime cluster information: cluster name, architecture (32
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or 64 bit), master node, node list and instance list.
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Passing the ``--roman`` option gnt-cluster info will try to print
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its integer fields in a latin friendly way. This allows further
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diffusion of Ganeti among ancient cultures.
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INIT
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~~~~
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| **init**
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| [{-s|--secondary-ip} *secondary\_ip*]
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| [--vg-name *vg-name*]
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| [--master-netdev *interface-name*]
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| [{-m|--mac-prefix} *mac-prefix*]
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| [--no-lvm-storage]
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| [--no-etc-hosts]
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| [--no-ssh-init]
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| [--file-storage-dir *dir*]
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| [--enabled-hypervisors *hypervisors*]
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| [-t *hypervisor name*]
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| [{-H|--hypervisor-parameters} *hypervisor*:*hv-param*=*value*[,*hv-param*=*value*...]]
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| [{-B|--backend-parameters} *be-param*=*value* [,*be-param*=*value*...]]
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| [{-N|--nic-parameters} *nic-param*=*value* [,*nic-param*=*value*...]]
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| [--maintain-node-health {yes \| no}]
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| [--uid-pool *user-id pool definition*]
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| [{-I|--default-iallocator} *default instance allocator*]
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| [--primary-ip-version *version*]
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| [--prealloc-wipe-disks {yes \| no}]
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| [--node-parameters *ndparams*]
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| [{-C|--candidate-pool-size} *candidate\_pool\_size*]
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| {*clustername*}
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This commands is only run once initially on the first node of the
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cluster. It will initialize the cluster configuration, setup the
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ssh-keys, start the daemons on the master node, etc. in order to have
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a working one-node cluster.
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Note that the *clustername* is not any random name. It has to be
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resolvable to an IP address using DNS, and it is best if you give the
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fully-qualified domain name. This hostname must resolve to an IP
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address reserved exclusively for this purpose, i.e. not already in
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use.
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The cluster can run in two modes: single-home or dual-homed. In the
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first case, all traffic (both public traffic, inter-node traffic and
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data replication traffic) goes over the same interface. In the
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dual-homed case, the data replication traffic goes over the second
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network. The ``-s (--secondary-ip)`` option here marks the cluster as
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dual-homed and its parameter represents this node's address on the
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second network.  If you initialise the cluster with ``-s``, all nodes
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added must have a secondary IP as well.
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Note that for Ganeti it doesn't matter if the secondary network is
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actually a separate physical network, or is done using tunneling,
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etc. For performance reasons, it's recommended to use a separate
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network, of course.
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The ``--vg-name`` option will let you specify a volume group
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different than "xenvg" for Ganeti to use when creating instance
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disks. This volume group must have the same name on all nodes. Once
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the cluster is initialized this can be altered by using the
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**modify** command. If you don't want to use lvm storage at all use
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the ``--no-lvm-storage`` option. Once the cluster is initialized
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you can change this setup with the **modify** command.
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The ``--master-netdev`` option is useful for specifying a different
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interface on which the master will activate its IP address. It's
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important that all nodes have this interface because you'll need it
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for a master failover.
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The ``-m (--mac-prefix)`` option will let you specify a three byte
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prefix under which the virtual MAC addresses of your instances will be
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generated. The prefix must be specified in the format ``XX:XX:XX`` and
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the default is ``aa:00:00``.
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The ``--no-lvm-storage`` option allows you to initialize the
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cluster without lvm support. This means that only instances using
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files as storage backend will be possible to create. Once the
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cluster is initialized you can change this setup with the
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**modify** command.
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The ``--no-etc-hosts`` option allows you to initialize the cluster
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without modifying the /etc/hosts file.
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The ``--no-ssh-init`` option allows you to initialize the cluster
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without creating or distributing SSH key pairs.
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The ``--file-storage-dir`` option allows you set the directory to
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use for storing the instance disk files when using file storage as
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backend for instance disks.
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The ``--prealloc-wipe-disks`` sets a cluster wide configuration
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value for wiping disks prior to allocation. This increases security
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on instance level as the instance can't access untouched data from
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it's underlying storage.
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The ``--enabled-hypervisors`` option allows you to set the list of
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hypervisors that will be enabled for this cluster. Instance
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hypervisors can only be chosen from the list of enabled
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hypervisors, and the first entry of this list will be used by
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default. Currently, the following hypervisors are available:
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xen-pvm
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    Xen PVM hypervisor
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xen-hvm
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    Xen HVM hypervisor
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kvm
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    Linux KVM hypervisor
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chroot
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    a simple chroot manager that starts chroot based on a script at the
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    root of the filesystem holding the chroot
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fake
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    fake hypervisor for development/testing
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Either a single hypervisor name or a comma-separated list of
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hypervisor names can be specified. If this option is not specified,
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only the xen-pvm hypervisor is enabled by default.
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The ``-H (--hypervisor-parameters)`` option allows you to set default
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hypervisor specific parameters for the cluster. The format of this
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option is the name of the hypervisor, followed by a colon and a
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comma-separated list of key=value pairs. The keys available for each
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hypervisors are detailed in the gnt-instance(8) man page, in the
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**add** command plus the following parameters which are only
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configurable globally (at cluster level):
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migration\_port
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    Valid for the Xen PVM and KVM hypervisors.
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    This options specifies the TCP port to use for live-migration. For
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    Xen, the same port should be configured on all nodes in the
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    ``/etc/xen/xend-config.sxp`` file, under the key
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    "xend-relocation-port".
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migration\_bandwidth
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    Valid for the KVM hypervisor.
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    This option specifies the maximum bandwidth that KVM will use for
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    instance live migrations. The value is in MiB/s.
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    This option is only effective with kvm versions >= 78 and qemu-kvm
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    versions >= 0.10.0.
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The ``-B (--backend-parameters)`` option allows you to set the default
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backend parameters for the cluster. The parameter format is a
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comma-separated list of key=value pairs with the following supported
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keys:
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vcpus
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    Number of VCPUs to set for an instance by default, must be an
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    integer, will be set to 1 if no specified.
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memory
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    Amount of memory to allocate for an instance by default, can be
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    either an integer or an integer followed by a unit (M for mebibytes
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    and G for gibibytes are supported), will be set to 128M if not
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    specified.
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auto\_balance
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    Value of the auto\_balance flag for instances to use by default,
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    will be set to true if not specified.
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The ``-N (--nic-parameters)`` option allows you to set the default nic
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parameters for the cluster. The parameter format is a comma-separated
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list of key=value pairs with the following supported keys:
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mode
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    The default nic mode, 'routed' or 'bridged'.
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link
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    In bridged mode the default NIC bridge. In routed mode it
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    represents an hypervisor-vif-script dependent value to allow
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    different instance groups. For example under the KVM default
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    network script it is interpreted as a routing table number or
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    name.
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The option ``--maintain-node-health`` allows one to enable/disable
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automatic maintenance actions on nodes. Currently these include
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automatic shutdown of instances and deactivation of DRBD devices on
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offline nodes; in the future it might be extended to automatic
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removal of unknown LVM volumes, etc.
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The ``--uid-pool`` option initializes the user-id pool. The
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*user-id pool definition* can contain a list of user-ids and/or a
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list of user-id ranges. The parameter format is a comma-separated
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list of numeric user-ids or user-id ranges. The ranges are defined
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by a lower and higher boundary, separated by a dash. The boundaries
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are inclusive. If the ``--uid-pool`` option is not supplied, the
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user-id pool is initialized to an empty list. An empty list means
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that the user-id pool feature is disabled.
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The ``-I (--default-iallocator)`` option specifies the default
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instance allocator. The instance allocator will be used for operations
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like instance creation, instance and node migration, etc. when no
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manual override is specified. If this option is not specified and
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htools was not enabled at build time, the default instance allocator
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will be blank, which means that relevant operations will require the
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administrator to manually specify either an instance allocator, or a
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set of nodes. If the option is not specified but htools was enabled,
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the default iallocator will be **hail**(1) (assuming it can be found
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on disk). The default iallocator can be changed later using the
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**modify** command.
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The ``--primary-ip-version`` option specifies the IP version used
346
for the primary address. Possible values are 4 and 6 for IPv4 and
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IPv6, respectively. This option is used when resolving node names
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and the cluster name.
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The ``--node-parameters`` option allows you to set default node
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parameters for the cluster. Please see **ganeti**(7) for more
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information about supported key=value pairs.
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The ``-C (--candidate-pool-size)`` option specifies the
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``candidate_pool_size`` cluster parameter. This is the number of nodes
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that the master will try to keep as master\_candidates. For more
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details about this role and other node roles, see the ganeti(7).
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LIST-TAGS
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~~~~~~~~~
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**list-tags**
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List the tags of the cluster.
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MASTER-FAILOVER
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~~~~~~~~~~~~~~~
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**master-failover** [--no-voting]
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Failover the master role to the current node.
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The ``--no-voting`` option skips the remote node agreement checks.
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This is dangerous, but necessary in some cases (for example failing
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over the master role in a 2 node cluster with the original master
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down). If the original master then comes up, it won't be able to
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start its master daemon because it won't have enough votes, but so
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won't the new master, if the master daemon ever needs a restart.
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You can pass ``--no-voting`` to **ganeti-masterd** on the new
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master to solve this problem, and run **gnt-cluster redist-conf**
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to make sure the cluster is consistent again.
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MASTER-PING
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~~~~~~~~~~~
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**master-ping**
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Checks if the master daemon is alive.
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If the master daemon is alive and can respond to a basic query (the
391
equivalent of **gnt-cluster info**), then the exit code of the
392
command will be 0. If the master daemon is not alive (either due to
393
a crash or because this is not the master node), the exit code will
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be 1.
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MODIFY
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~~~~~~
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399
| **modify**
400
| [--vg-name *vg-name*]
401
| [--no-lvm-storage]
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| [--enabled-hypervisors *hypervisors*]
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| [{-H|--hypervisor-parameters} *hypervisor*:*hv-param*=*value*[,*hv-param*=*value*...]]
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| [{-B|--backend-parameters} *be-param*=*value* [,*be-param*=*value*...]]
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| [{-N|--nic-parameters} *nic-param*=*value* [,*nic-param*=*value*...]]
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| [--uid-pool *user-id pool definition*]
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| [--add-uids *user-id pool definition*]
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| [--remove-uids *user-id pool definition*]
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| [{-C|--candidate-pool-size} *candidate\_pool\_size*]
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| [--maintain-node-health {yes \| no}]
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| [--prealloc-wipe-disks {yes \| no}]
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| [{-I|--default-iallocator} *default instance allocator*]
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| [--reserved-lvs=*NAMES*]
414
| [--node-parameters *ndparams*]
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| [--master-netdev *interface-name*]
416

    
417
Modify the options for the cluster.
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The ``--vg-name``, ``--no-lvm-storarge``, ``--enabled-hypervisors``,
420
``-H (--hypervisor-parameters)``, ``-B (--backend-parameters)``,
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``--nic-parameters``, ``-C (--candidate-pool-size)``,
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``--maintain-node-health``, ``--prealloc-wipe-disks``, ``--uid-pool``,
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``--node-parameters``, ``--master-netdev`` options are described in
424
the **init** command.
425

    
426
The ``--add-uids`` and ``--remove-uids`` options can be used to
427
modify the user-id pool by adding/removing a list of user-ids or
428
user-id ranges.
429

    
430
The option ``--reserved-lvs`` specifies a list (comma-separated) of
431
logical volume group names (regular expressions) that will be
432
ignored by the cluster verify operation. This is useful if the
433
volume group used for Ganeti is shared with the system for other
434
uses. Note that it's not recommended to create and mark as ignored
435
logical volume names which match Ganeti's own name format (starting
436
with UUID and then .diskN), as this option only skips the
437
verification, but not the actual use of the names given.
438

    
439
To remove all reserved logical volumes, pass in an empty argument
440
to the option, as in ``--reserved-lvs=`` or ``--reserved-lvs ''``.
441

    
442
The ``-I (--default-iallocator)`` is described in the **init**
443
command. To clear the default iallocator, just pass an empty string
444
('').
445

    
446
QUEUE
447
~~~~~
448

    
449
**queue** {drain | undrain | info}
450

    
451
Change job queue properties.
452

    
453
The ``drain`` option sets the drain flag on the job queue. No new
454
jobs will be accepted, but jobs already in the queue will be
455
processed.
456

    
457
The ``undrain`` will unset the drain flag on the job queue. New
458
jobs will be accepted.
459

    
460
The ``info`` option shows the properties of the job queue.
461

    
462
WATCHER
463
~~~~~~~
464

    
465
**watcher** {pause *duration* | continue | info}
466

    
467
Make the watcher pause or let it continue.
468

    
469
The ``pause`` option causes the watcher to pause for *duration*
470
seconds.
471

    
472
The ``continue`` option will let the watcher continue.
473

    
474
The ``info`` option shows whether the watcher is currently paused.
475

    
476
redist-conf
477
~~~~~~~~~~~
478

    
479
**redist-conf** [--submit]
480

    
481
This command forces a full push of configuration files from the
482
master node to the other nodes in the cluster. This is normally not
483
needed, but can be run if the **verify** complains about
484
configuration mismatches.
485

    
486
The ``--submit`` option is used to send the job to the master
487
daemon but not wait for its completion. The job ID will be shown so
488
that it can be examined via **gnt-job info**.
489

    
490
REMOVE-TAGS
491
~~~~~~~~~~~
492

    
493
**remove-tags** [--from *file*] {*tag*...}
494

    
495
Remove tags from the cluster. If any of the tags are not existing
496
on the cluster, the entire operation will abort.
497

    
498
If the ``--from`` option is given, the list of tags to be removed will
499
be extended with the contents of that file (each line becomes a tag).
500
In this case, there is not need to pass tags on the command line (if
501
you do, tags from both sources will be removed). A file name of - will
502
be interpreted as stdin.
503

    
504
RENAME
505
~~~~~~
506

    
507
**rename** [-f] {*name*}
508

    
509
Renames the cluster and in the process updates the master IP
510
address to the one the new name resolves to. At least one of either
511
the name or the IP address must be different, otherwise the
512
operation will be aborted.
513

    
514
Note that since this command can be dangerous (especially when run
515
over SSH), the command will require confirmation unless run with
516
the ``-f`` option.
517

    
518
RENEW-CRYPTO
519
~~~~~~~~~~~~
520

    
521
| **renew-crypto** [-f]
522
| [--new-cluster-certificate] [--new-confd-hmac-key]
523
| [--new-rapi-certificate] [--rapi-certificate *rapi-cert*]
524
| [--new-cluster-domain-secret] [--cluster-domain-secret *filename*]
525

    
526
This command will stop all Ganeti daemons in the cluster and start
527
them again once the new certificates and keys are replicated. The
528
options ``--new-cluster-certificate`` and ``--new-confd-hmac-key``
529
can be used to regenerate the cluster-internal SSL certificate
530
respective the HMAC key used by ganeti-confd(8).
531

    
532
To generate a new self-signed RAPI certificate (used by
533
ganeti-rapi(8)) specify ``--new-rapi-certificate``. If you want to
534
use your own certificate, e.g. one signed by a certificate
535
authority (CA), pass its filename to ``--rapi-certificate``.
536

    
537
``--new-cluster-domain-secret`` generates a new, random cluster
538
domain secret. ``--cluster-domain-secret`` reads the secret from a
539
file. The cluster domain secret is used to sign information
540
exchanged between separate clusters via a third party.
541

    
542
REPAIR-DISK-SIZES
543
~~~~~~~~~~~~~~~~~
544

    
545
**repair-disk-sizes** [instance...]
546

    
547
This command checks that the recorded size of the given instance's
548
disks matches the actual size and updates any mismatches found.
549
This is needed if the Ganeti configuration is no longer consistent
550
with reality, as it will impact some disk operations. If no
551
arguments are given, all instances will be checked.
552

    
553
Note that only active disks can be checked by this command; in case
554
a disk cannot be activated it's advised to use
555
**gnt-instance activate-disks --ignore-size ...** to force
556
activation without regard to the current size.
557

    
558
When the all disk sizes are consistent, the command will return no
559
output. Otherwise it will log details about the inconsistencies in
560
the configuration.
561

    
562
SEARCH-TAGS
563
~~~~~~~~~~~
564

    
565
**search-tags** {*pattern*}
566

    
567
Searches the tags on all objects in the cluster (the cluster
568
itself, the nodes and the instances) for a given pattern. The
569
pattern is interpreted as a regular expression and a search will be
570
done on it (i.e. the given pattern is not anchored to the beggining
571
of the string; if you want that, prefix the pattern with ^).
572

    
573
If no tags are matching the pattern, the exit code of the command
574
will be one. If there is at least one match, the exit code will be
575
zero. Each match is listed on one line, the object and the tag
576
separated by a space. The cluster will be listed as /cluster, a
577
node will be listed as /nodes/*name*, and an instance as
578
/instances/*name*. Example:
579

    
580
::
581

    
582
    # gnt-cluster search-tags time
583
    /cluster ctime:2007-09-01
584
    /nodes/node1.example.com mtime:2007-10-04
585

    
586
VERIFY
587
~~~~~~
588

    
589
**verify** [--no-nplus1-mem] [--node-group *nodegroup*]
590

    
591
Verify correctness of cluster configuration. This is safe with
592
respect to running instances, and incurs no downtime of the
593
instances.
594

    
595
If the ``--no-nplus1-mem`` option is given, Ganeti won't check
596
whether if it loses a node it can restart all the instances on
597
their secondaries (and report an error otherwise).
598

    
599
With ``--node-group``, restrict the verification to those nodes and
600
instances that live in the named group. This will not verify global
601
settings, but will allow to perform verification of a group while other
602
operations are ongoing in other groups.
603

    
604
VERIFY-DISKS
605
~~~~~~~~~~~~
606

    
607
**verify-disks**
608

    
609
The command checks which instances have degraded DRBD disks and
610
activates the disks of those instances.
611

    
612
This command is run from the **ganeti-watcher** tool, which also
613
has a different, complementary algorithm for doing this check.
614
Together, these two should ensure that DRBD disks are kept
615
consistent.
616

    
617
VERSION
618
~~~~~~~
619

    
620
**version**
621

    
622
Show the cluster version.
623

    
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.. vim: set textwidth=72 :
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.. Local Variables:
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.. mode: rst
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.. fill-column: 72
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.. End: