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gnt-cluster(8) Ganeti | Version @GANETI_VERSION@

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Name

----

gnt-cluster - Ganeti administration, cluster-wide

Synopsis

--------

**gnt-cluster** {command} [arguments...]

DESCRIPTION

-----------

The **gnt-cluster** is used for cluster-wide administration in the

Ganeti system.

COMMANDS

--------

ADD-TAGS

~~~~~~~~

**add-tags** [--from *file*] {*tag*...}

Add tags to the cluster. If any of the tags contains invalid

characters, the entire operation will abort.

If the ``--from`` option is given, the list of tags will be

extended with the contents of that file (each line becomes a tag).

In this case, there is not need to pass tags on the command line

(if you do, both sources will be used). A file name of - will be

interpreted as stdin.

COMMAND

~~~~~~~

**command** [-n *node*] [-g *group*] {*command*}

Executes a command on all nodes. If the option ``-n`` is not given,

the command will be executed on all nodes, otherwise it will be

executed only on the node(s) specified. Use the option multiple

times for running it on multiple nodes, like::

    # gnt-cluster command -n node1.example.com -n node2.example.com date

The ``-g`` option can be used to run a command only on a specific node

group, e.g.::

    # gnt-cluster command -g default date

The command is executed serially on the selected nodes. If the

master node is present in the list, the command will be executed

last on the master. Regarding the other nodes, the execution order

is somewhat alphabetic, so that node2.example.com will be earlier

than node10.example.com but after node1.example.com.

So given the node names node1, node2, node3, node10, node11, with

node3 being the master, the order will be: node1, node2, node10,

node11, node3.

The command is constructed by concatenating all other command line

arguments. For example, to list the contents of the /etc directory

on all nodes, run::

    # gnt-cluster command ls -l /etc

and the command which will be executed will be ``ls -l /etc``.

COPYFILE

~~~~~~~~

| **copyfile** [--use-replication-network] [-n *node*] [-g *group*]

| {*file*}

Copies a file to all or to some nodes. The argument specifies the

source file (on the current system), the ``-n`` argument specifies

the target node, or nodes if the option is given multiple times. If

``-n`` is not given at all, the file will be copied to all nodes. The

``-g`` option can be used to only select nodes in a specific node group.

Passing the ``--use-replication-network`` option will cause the

copy to be done over the replication network (only matters if the

primary/secondary IPs are different). Example::

    # gnt-cluster -n node1.example.com -n node2.example.com copyfile /tmp/test

This will copy the file /tmp/test from the current node to the two

named nodes.

DESTROY

~~~~~~~

**destroy** {--yes-do-it}

Remove all configuration files related to the cluster, so that a

**gnt-cluster init** can be done again afterwards.

Since this is a dangerous command, you are required to pass the

argument *--yes-do-it.*

EPO

~~~

**epo** [--on] [--groups|--all] [--power-delay] *arguments*

Performs an emergency power-off on nodes given as arguments. If

``--groups`` is given, arguments are node groups. If ``--all`` is

provided, the whole cluster will be shut down.

The ``--on`` flag recovers the cluster after an emergency power-off.

When powering on the cluster you can use ``--power-delay`` to define the

time in seconds (fractions allowed) waited between powering on

individual nodes.

Please note that the master node will not be turned down or up

automatically.  It will just be left in a state, where you can manully

perform the shutdown of that one node. If the master is in the list of

affected nodes and this is not a complete cluster emergency power-off

(e.g. using ``--all``), you're required to do a master failover to

another node not affected.

GETMASTER

~~~~~~~~~

**getmaster**

Displays the current master node.

INFO

~~~~

**info** [--roman]

Shows runtime cluster information: cluster name, architecture (32

or 64 bit), master node, node list and instance list.

Passing the ``--roman`` option gnt-cluster info will try to print

its integer fields in a latin friendly way. This allows further

diffusion of Ganeti among ancient cultures.

INIT

~~~~

| **init**

| [{-s|--secondary-ip} *secondary\_ip*]

| [--vg-name *vg-name*]

| [--master-netdev *interface-name*]

| [{-m|--mac-prefix} *mac-prefix*]

| [--no-lvm-storage]

| [--no-etc-hosts]

| [--no-ssh-init]

| [--file-storage-dir *dir*]

| [--enabled-hypervisors *hypervisors*]

| [-t *hypervisor name*]

| [{-H|--hypervisor-parameters} *hypervisor*:*hv-param*=*value*[,*hv-param*=*value*...]]

| [{-B|--backend-parameters} *be-param*=*value* [,*be-param*=*value*...]]

| [{-N|--nic-parameters} *nic-param*=*value* [,*nic-param*=*value*...]]

| [--maintain-node-health {yes \| no}]

| [--uid-pool *user-id pool definition*]

| [{-I|--default-iallocator} *default instance allocator*]

| [--primary-ip-version *version*]

| [--prealloc-wipe-disks {yes \| no}]

| [--node-parameters *ndparams*]

| [{-C|--candidate-pool-size} *candidate\_pool\_size*]

| {*clustername*}

This commands is only run once initially on the first node of the

cluster. It will initialize the cluster configuration, setup the

ssh-keys, start the daemons on the master node, etc. in order to have

a working one-node cluster.

Note that the *clustername* is not any random name. It has to be

resolvable to an IP address using DNS, and it is best if you give the

fully-qualified domain name. This hostname must resolve to an IP

address reserved exclusively for this purpose, i.e. not already in

use.

The cluster can run in two modes: single-home or dual-homed. In the

first case, all traffic (both public traffic, inter-node traffic and

data replication traffic) goes over the same interface. In the

dual-homed case, the data replication traffic goes over the second

network. The ``-s (--secondary-ip)`` option here marks the cluster as

dual-homed and its parameter represents this node's address on the

second network.  If you initialise the cluster with ``-s``, all nodes

added must have a secondary IP as well.

Note that for Ganeti it doesn't matter if the secondary network is

actually a separate physical network, or is done using tunneling,

etc. For performance reasons, it's recommended to use a separate

network, of course.

The ``--vg-name`` option will let you specify a volume group

different than "xenvg" for Ganeti to use when creating instance

disks. This volume group must have the same name on all nodes. Once

the cluster is initialized this can be altered by using the

**modify** command. If you don't want to use lvm storage at all use

the ``--no-lvm-storage`` option. Once the cluster is initialized

you can change this setup with the **modify** command.

The ``--master-netdev`` option is useful for specifying a different

interface on which the master will activate its IP address. It's

important that all nodes have this interface because you'll need it

for a master failover.

The ``-m (--mac-prefix)`` option will let you specify a three byte

prefix under which the virtual MAC addresses of your instances will be

generated. The prefix must be specified in the format ``XX:XX:XX`` and

the default is ``aa:00:00``.

The ``--no-lvm-storage`` option allows you to initialize the

cluster without lvm support. This means that only instances using

files as storage backend will be possible to create. Once the

cluster is initialized you can change this setup with the

**modify** command.

The ``--no-etc-hosts`` option allows you to initialize the cluster

without modifying the /etc/hosts file.

The ``--no-ssh-init`` option allows you to initialize the cluster

without creating or distributing SSH key pairs.

The ``--file-storage-dir`` option allows you set the directory to

use for storing the instance disk files when using file storage as

backend for instance disks.

The ``--prealloc-wipe-disks`` sets a cluster wide configuration

value for wiping disks prior to allocation. This increases security

on instance level as the instance can't access untouched data from

it's underlying storage.

The ``--enabled-hypervisors`` option allows you to set the list of

hypervisors that will be enabled for this cluster. Instance

hypervisors can only be chosen from the list of enabled

hypervisors, and the first entry of this list will be used by

default. Currently, the following hypervisors are available:

xen-pvm

    Xen PVM hypervisor

xen-hvm

    Xen HVM hypervisor

kvm

    Linux KVM hypervisor

chroot

    a simple chroot manager that starts chroot based on a script at the

    root of the filesystem holding the chroot

fake

    fake hypervisor for development/testing

Either a single hypervisor name or a comma-separated list of

hypervisor names can be specified. If this option is not specified,

only the xen-pvm hypervisor is enabled by default.

The ``-H (--hypervisor-parameters)`` option allows you to set default

hypervisor specific parameters for the cluster. The format of this

option is the name of the hypervisor, followed by a colon and a

comma-separated list of key=value pairs. The keys available for each

hypervisors are detailed in the gnt-instance(8) man page, in the

**add** command plus the following parameters which are only

configurable globally (at cluster level):

migration\_port

    Valid for the Xen PVM and KVM hypervisors.

    This options specifies the TCP port to use for live-migration. For

    Xen, the same port should be configured on all nodes in the

    ``/etc/xen/xend-config.sxp`` file, under the key

    "xend-relocation-port".

migration\_bandwidth

    Valid for the KVM hypervisor.

    This option specifies the maximum bandwidth that KVM will use for

    instance live migrations. The value is in MiB/s.

    This option is only effective with kvm versions >= 78 and qemu-kvm

    versions >= 0.10.0.

The ``-B (--backend-parameters)`` option allows you to set the default

backend parameters for the cluster. The parameter format is a

comma-separated list of key=value pairs with the following supported

keys:

vcpus

    Number of VCPUs to set for an instance by default, must be an

    integer, will be set to 1 if no specified.

memory

    Amount of memory to allocate for an instance by default, can be

    either an integer or an integer followed by a unit (M for mebibytes

    and G for gibibytes are supported), will be set to 128M if not

    specified.

auto\_balance

    Value of the auto\_balance flag for instances to use by default,

    will be set to true if not specified.

The ``-N (--nic-parameters)`` option allows you to set the default nic

parameters for the cluster. The parameter format is a comma-separated

list of key=value pairs with the following supported keys:

mode

    The default nic mode, 'routed' or 'bridged'.

link

    In bridged mode the default NIC bridge. In routed mode it

    represents an hypervisor-vif-script dependent value to allow

    different instance groups. For example under the KVM default

    network script it is interpreted as a routing table number or

    name.

The option ``--maintain-node-health`` allows one to enable/disable

automatic maintenance actions on nodes. Currently these include

automatic shutdown of instances and deactivation of DRBD devices on

offline nodes; in the future it might be extended to automatic

removal of unknown LVM volumes, etc.

The ``--uid-pool`` option initializes the user-id pool. The

*user-id pool definition* can contain a list of user-ids and/or a

list of user-id ranges. The parameter format is a comma-separated

list of numeric user-ids or user-id ranges. The ranges are defined

by a lower and higher boundary, separated by a dash. The boundaries

are inclusive. If the ``--uid-pool`` option is not supplied, the

user-id pool is initialized to an empty list. An empty list means

that the user-id pool feature is disabled.

The ``-I (--default-iallocator)`` option specifies the default

instance allocator. The instance allocator will be used for operations

like instance creation, instance and node migration, etc. when no

manual override is specified. If this option is not specified and

htools was not enabled at build time, the default instance allocator

will be blank, which means that relevant operations will require the

administrator to manually specify either an instance allocator, or a

set of nodes. If the option is not specified but htools was enabled,

the default iallocator will be **hail**(1) (assuming it can be found

on disk). The default iallocator can be changed later using the

**modify** command.

The ``--primary-ip-version`` option specifies the IP version used

for the primary address. Possible values are 4 and 6 for IPv4 and

IPv6, respectively. This option is used when resolving node names

and the cluster name.

The ``--node-parameters`` option allows you to set default node

parameters for the cluster. Please see **ganeti**(7) for more

information about supported key=value pairs.

The ``-C (--candidate-pool-size)`` option specifies the

``candidate_pool_size`` cluster parameter. This is the number of nodes

that the master will try to keep as master\_candidates. For more

details about this role and other node roles, see the ganeti(7).

LIST-TAGS

~~~~~~~~~

**list-tags**

List the tags of the cluster.

MASTER-FAILOVER

~~~~~~~~~~~~~~~

**master-failover** [--no-voting]

Failover the master role to the current node.

The ``--no-voting`` option skips the remote node agreement checks.

This is dangerous, but necessary in some cases (for example failing

over the master role in a 2 node cluster with the original master

down). If the original master then comes up, it won't be able to

start its master daemon because it won't have enough votes, but so

won't the new master, if the master daemon ever needs a restart.

You can pass ``--no-voting`` to **ganeti-masterd** on the new

master to solve this problem, and run **gnt-cluster redist-conf**

to make sure the cluster is consistent again.

MASTER-PING

~~~~~~~~~~~

**master-ping**

Checks if the master daemon is alive.

If the master daemon is alive and can respond to a basic query (the

equivalent of **gnt-cluster info**), then the exit code of the

command will be 0. If the master daemon is not alive (either due to

a crash or because this is not the master node), the exit code will

be 1.

MODIFY

~~~~~~

| **modify**

| [--vg-name *vg-name*]

| [--no-lvm-storage]

| [--enabled-hypervisors *hypervisors*]

| [{-H|--hypervisor-parameters} *hypervisor*:*hv-param*=*value*[,*hv-param*=*value*...]]

| [{-B|--backend-parameters} *be-param*=*value* [,*be-param*=*value*...]]

| [{-N|--nic-parameters} *nic-param*=*value* [,*nic-param*=*value*...]]

| [--uid-pool *user-id pool definition*]

| [--add-uids *user-id pool definition*]

| [--remove-uids *user-id pool definition*]

| [{-C|--candidate-pool-size} *candidate\_pool\_size*]

| [--maintain-node-health {yes \| no}]

| [--prealloc-wipe-disks {yes \| no}]

| [{-I|--default-iallocator} *default instance allocator*]

| [--reserved-lvs=*NAMES*]

| [--node-parameters *ndparams*]

| [--master-netdev *interface-name*]

Modify the options for the cluster.

The ``--vg-name``, ``--no-lvm-storarge``, ``--enabled-hypervisors``,

``-H (--hypervisor-parameters)``, ``-B (--backend-parameters)``,

``--nic-parameters``, ``-C (--candidate-pool-size)``,

``--maintain-node-health``, ``--prealloc-wipe-disks``, ``--uid-pool``,

``--node-parameters``, ``--master-netdev`` options are described in

the **init** command.

The ``--add-uids`` and ``--remove-uids`` options can be used to

modify the user-id pool by adding/removing a list of user-ids or

user-id ranges.

The option ``--reserved-lvs`` specifies a list (comma-separated) of

logical volume group names (regular expressions) that will be

ignored by the cluster verify operation. This is useful if the

volume group used for Ganeti is shared with the system for other

uses. Note that it's not recommended to create and mark as ignored

logical volume names which match Ganeti's own name format (starting

with UUID and then .diskN), as this option only skips the

verification, but not the actual use of the names given.

To remove all reserved logical volumes, pass in an empty argument

to the option, as in ``--reserved-lvs=`` or ``--reserved-lvs ''``.

The ``-I (--default-iallocator)`` is described in the **init**

command. To clear the default iallocator, just pass an empty string

('').

QUEUE

~~~~~

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

Change job queue properties.

The ``drain`` option sets the drain flag on the job queue. No new

jobs will be accepted, but jobs already in the queue will be

processed.

The ``undrain`` will unset the drain flag on the job queue. New

jobs will be accepted.

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

WATCHER

~~~~~~~

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

Make the watcher pause or let it continue.

The ``pause`` option causes the watcher to pause for *duration*

seconds.

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

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

redist-conf

~~~~~~~~~~~

**redist-conf** [--submit]

This command forces a full push of configuration files from the

master node to the other nodes in the cluster. This is normally not

needed, but can be run if the **verify** complains about

configuration mismatches.

The ``--submit`` option is used to send the job to the master

daemon but not wait for its completion. The job ID will be shown so

that it can be examined via **gnt-job info**.

REMOVE-TAGS

~~~~~~~~~~~

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

Remove tags from the cluster. If any of the tags are not existing

on the cluster, the entire operation will abort.

If the ``--from`` option is given, the list of tags to be removed will

be extended with the contents of that file (each line becomes a tag).

In this case, there is not need to pass tags on the command line (if

you do, tags from both sources will be removed). A file name of - will

be interpreted as stdin.

RENAME

~~~~~~

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

Renames the cluster and in the process updates the master IP

address to the one the new name resolves to. At least one of either

the name or the IP address must be different, otherwise the

operation will be aborted.

Note that since this command can be dangerous (especially when run

over SSH), the command will require confirmation unless run with

the ``-f`` option.

RENEW-CRYPTO

~~~~~~~~~~~~

| **renew-crypto** [-f]

| [--new-cluster-certificate] [--new-confd-hmac-key]

| [--new-rapi-certificate] [--rapi-certificate *rapi-cert*]

| [--new-cluster-domain-secret] [--cluster-domain-secret *filename*]

This command will stop all Ganeti daemons in the cluster and start

them again once the new certificates and keys are replicated. The

options ``--new-cluster-certificate`` and ``--new-confd-hmac-key``

can be used to regenerate the cluster-internal SSL certificate

respective the HMAC key used by ganeti-confd(8).

To generate a new self-signed RAPI certificate (used by

ganeti-rapi(8)) specify ``--new-rapi-certificate``. If you want to

use your own certificate, e.g. one signed by a certificate

authority (CA), pass its filename to ``--rapi-certificate``.

``--new-cluster-domain-secret`` generates a new, random cluster

domain secret. ``--cluster-domain-secret`` reads the secret from a

file. The cluster domain secret is used to sign information

exchanged between separate clusters via a third party.

REPAIR-DISK-SIZES

~~~~~~~~~~~~~~~~~

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

This command checks that the recorded size of the given instance's

disks matches the actual size and updates any mismatches found.

This is needed if the Ganeti configuration is no longer consistent

with reality, as it will impact some disk operations. If no

arguments are given, all instances will be checked.

Note that only active disks can be checked by this command; in case

a disk cannot be activated it's advised to use

**gnt-instance activate-disks --ignore-size ...** to force

activation without regard to the current size.

When the all disk sizes are consistent, the command will return no

output. Otherwise it will log details about the inconsistencies in

the configuration.

SEARCH-TAGS

~~~~~~~~~~~

**search-tags** {*pattern*}

Searches the tags on all objects in the cluster (the cluster

itself, the nodes and the instances) for a given pattern. The

pattern is interpreted as a regular expression and a search will be

done on it (i.e. the given pattern is not anchored to the beggining

of the string; if you want that, prefix the pattern with ^).

If no tags are matching the pattern, the exit code of the command

will be one. If there is at least one match, the exit code will be

zero. Each match is listed on one line, the object and the tag

separated by a space. The cluster will be listed as /cluster, a

node will be listed as /nodes/*name*, and an instance as

/instances/*name*. Example:

::

    # gnt-cluster search-tags time

    /cluster ctime:2007-09-01

    /nodes/node1.example.com mtime:2007-10-04

VERIFY

~~~~~~

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

Verify correctness of cluster configuration. This is safe with

respect to running instances, and incurs no downtime of the

instances.

If the ``--no-nplus1-mem`` option is given, Ganeti won't check

whether if it loses a node it can restart all the instances on

their secondaries (and report an error otherwise).

With ``--node-group``, restrict the verification to those nodes and

instances that live in the named group. This will not verify global

settings, but will allow to perform verification of a group while other

operations are ongoing in other groups.

VERIFY-DISKS

~~~~~~~~~~~~

**verify-disks**

The command checks which instances have degraded DRBD disks and

activates the disks of those instances.

This command is run from the **ganeti-watcher** tool, which also

has a different, complementary algorithm for doing this check.

Together, these two should ensure that DRBD disks are kept

consistent.

VERSION

~~~~~~~

**version**

Show the cluster version.

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