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

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Name

----

gnt-instance - Ganeti instance administration

Synopsis

--------

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

DESCRIPTION

-----------

The **gnt-instance** command is used for instance administration in

the Ganeti system.

COMMANDS

--------

Creation/removal/querying

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

ADD

^^^

| **add**

| {-t {diskless | file \| plain \| drbd}}

| {--disk=*N*: {size=*VAL* \| adopt=*LV*}[,vg=*VG*][,mode=*ro\|rw*]

|  \| -s *SIZE*}

| [--no-ip-check] [--no-name-check] [--no-start] [--no-install]

| [--net=*N* [:options...] \| --no-nics]

| [-B *BEPARAMS*]

| [-H *HYPERVISOR* [: option=*value*... ]]

| [--file-storage-dir *dir\_path*] [--file-driver {loop \| blktap}]

| {-n *node[:secondary-node]* \| --iallocator *name*}

| {-o *os-type*}

| [--submit]

| {*instance*}

Creates a new instance on the specified host. The *instance* argument

must be in DNS, but depending on the bridge/routing setup, need not be

in the same network as the nodes in the cluster.

The ``disk`` option specifies the parameters for the disks of the

instance. The numbering of disks starts at zero, and at least one disk

needs to be passed. For each disk, either the size or the adoption

source needs to be given, and optionally the access mode (read-only or

the default of read-write) and LVM volume group can also be specified.

The size is interpreted (when no unit is given) in mebibytes. You can

also use one of the suffixes *m*, *g* or *t* to specify the exact the

units used; these suffixes map to mebibytes, gibibytes and tebibytes.

When using the ``adopt`` key in the disk definition, Ganeti will

reuse those volumes (instead of creating new ones) as the

instance's disks. Ganeti will rename these volumes to the standard

format, and (without installing the OS) will use them as-is for the

instance. This allows migrating instances from non-managed mode

(e.q. plain KVM with LVM) to being managed via Ganeti. Note that

this works only for the \`plain' disk template (see below for

template details).

Alternatively, a single-disk instance can be created via the ``-s``

option which takes a single argument, the size of the disk. This is

similar to the Ganeti 1.2 version (but will only create one disk).

The minimum disk specification is therefore ``--disk 0:size=20G`` (or

``-s 20G`` when using the ``-s`` option), and a three-disk instance

can be specified as ``--disk 0:size=20G --disk 1:size=4G --disk

2:size=100G``.

The ``--no-ip-check`` skips the checks that are done to see if the

instance's IP is not already alive (i.e. reachable from the master

node).

The ``--no-name-check`` skips the check for the instance name via

the resolver (e.g. in DNS or /etc/hosts, depending on your setup).

Since the name check is used to compute the IP address, if you pass

this option you must also pass the ``--no-ip-check`` option.

If you don't wat the instance to automatically start after

creation, this is possible via the ``--no-start`` option. This will

leave the instance down until a subsequent **gnt-instance start**

command.

The NICs of the instances can be specified via the ``--net``

option. By default, one NIC is created for the instance, with a

random MAC, and set up according the the cluster level nic

parameters. Each NIC can take these parameters (all optional):

mac

    either a value or 'generate' to generate a new unique MAC

ip

    specifies the IP address assigned to the instance from the Ganeti

    side (this is not necessarily what the instance will use, but what

    the node expects the instance to use)

mode

    specifies the connection mode for this nic: routed or bridged.

link

    in bridged mode specifies the bridge to attach this NIC to, in

    routed mode it's intended to differentiate between different

    routing tables/instance groups (but the meaning is dependent on the

    network script, see gnt-cluster(8) for more details)

Of these "mode" and "link" are nic parameters, and inherit their

default at cluster level.

Alternatively, if no network is desired for the instance, you can

prevent the default of one NIC with the ``--no-nics`` option.

The ``-o`` options specifies the operating system to be installed.

The available operating systems can be listed with **gnt-os list**.

Passing ``--no-install`` will however skip the OS installation,

allowing a manual import if so desired. Note that the

no-installation mode will automatically disable the start-up of the

instance (without an OS, it most likely won't be able to start-up

successfully).

The ``-B`` option specifies the backend parameters for the

instance. If no such parameters are specified, the values are

inherited from the cluster. Possible parameters are:

memory

    the memory size of the instance; as usual, suffixes can be used to

    denote the unit, otherwise the value is taken in mebibites

vcpus

    the number of VCPUs to assign to the instance (if this value makes

    sense for the hypervisor)

auto\_balance

    whether the instance is considered in the N+1 cluster checks

    (enough redundancy in the cluster to survive a node failure)

The ``-H`` option specified the hypervisor to use for the instance

(must be one of the enabled hypervisors on the cluster) and

optionally custom parameters for this instance. If not other

options are used (i.e. the invocation is just -H *NAME*) the

instance will inherit the cluster options. The defaults below show

the cluster defaults at cluster creation time.

The possible hypervisor options are as follows:

boot\_order

    Valid for the Xen HVM and KVM hypervisors.

    A string value denoting the boot order. This has different meaning

    for the Xen HVM hypervisor and for the KVM one.

    For Xen HVM, The boot order is a string of letters listing the boot

    devices, with valid device letters being:

    a

        floppy drive

    c

        hard disk

    d

        CDROM drive

    n

        network boot (PXE)

    The default is not to set an HVM boot order which is interpreted as

    'dc'.

    For KVM the boot order is either "cdrom", "disk" or "network".

    Please note that older versions of KVM couldn't netboot from virtio

    interfaces. This has been fixed in more recent versions and is

    confirmed to work at least with qemu-kvm 0.11.1.

cdrom\_image\_path

    Valid for the Xen HVM and KVM hypervisors.

    The path to a CDROM image to attach to the instance.

nic\_type

    Valid for the Xen HVM and KVM hypervisors.

    This parameter determines the way the network cards are presented

    to the instance. The possible options are:

    rtl8139 (default for Xen HVM) (HVM & KVM)

    ne2k\_isa (HVM & KVM)

    ne2k\_pci (HVM & KVM)

    i82551 (KVM)

    i82557b (KVM)

    i82559er (KVM)

    pcnet (KVM)

    e1000 (KVM)

    paravirtual (default for KVM) (HVM & KVM)

disk\_type

    Valid for the Xen HVM and KVM hypervisors.

    This parameter determines the way the disks are presented to the

    instance. The possible options are:

    ioemu (default for HVM & KVM) (HVM & KVM)

    ide (HVM & KVM)

    scsi (KVM)

    sd (KVM)

    mtd (KVM)

    pflash (KVM)

vnc\_bind\_address

    Valid for the Xen HVM and KVM hypervisors.

    Specifies the address that the VNC listener for this instance

    should bind to. Valid values are IPv4 addresses. Use the address

    0.0.0.0 to bind to all available interfaces (this is the default)

    or specify the address of one of the interfaces on the node to

    restrict listening to that interface.

vnc\_tls

    Valid for the KVM hypervisor.

    A boolean option that controls whether the VNC connection is

    secured with TLS.

vnc\_x509\_path

    Valid for the KVM hypervisor.

    If ``vnc_tls`` is enabled, this options specifies the path to the

    x509 certificate to use.

vnc\_x509\_verify

    Valid for the KVM hypervisor.

acpi

    Valid for the Xen HVM and KVM hypervisors.

    A boolean option that specifies if the hypervisor should enable

    ACPI support for this instance. By default, ACPI is disabled.

pae

    Valid for the Xen HVM and KVM hypervisors.

    A boolean option that specifies if the hypervisor should enabled

    PAE support for this instance. The default is false, disabling PAE

    support.

use\_localtime

    Valid for the Xen HVM and KVM hypervisors.

    A boolean option that specifies if the instance should be started

    with its clock set to the localtime of the machine (when true) or

    to the UTC (When false). The default is false, which is useful for

    Linux/Unix machines; for Windows OSes, it is recommended to enable

    this parameter.

kernel\_path

    Valid for the Xen PVM and KVM hypervisors.

    This option specifies the path (on the node) to the kernel to boot

    the instance with. Xen PVM instances always require this, while for

    KVM if this option is empty, it will cause the machine to load the

    kernel from its disks.

kernel\_args

    Valid for the Xen PVM and KVM hypervisors.

    This options specifies extra arguments to the kernel that will be

    loaded. device. This is always used for Xen PVM, while for KVM it

    is only used if the ``kernel_path`` option is also specified.

    The default setting for this value is simply ``"ro"``, which mounts

    the root disk (initially) in read-only one. For example, setting

    this to single will cause the instance to start in single-user

    mode.

initrd\_path

    Valid for the Xen PVM and KVM hypervisors.

    This option specifies the path (on the node) to the initrd to boot

    the instance with. Xen PVM instances can use this always, while for

    KVM if this option is only used if the ``kernel_path`` option is

    also specified. You can pass here either an absolute filename (the

    path to the initrd) if you want to use an initrd, or use the format

    no\_initrd\_path for no initrd.

root\_path

    Valid for the Xen PVM and KVM hypervisors.

    This options specifies the name of the root device. This is always

    needed for Xen PVM, while for KVM it is only used if the

    ``kernel_path`` option is also specified.

serial\_console

    Valid for the KVM hypervisor.

    This boolean option specifies whether to emulate a serial console

    for the instance.

disk\_cache

    Valid for the KVM hypervisor.

    The disk cache mode. It can be either default to not pass any cache

    option to KVM, or one of the KVM cache modes: none (for direct

    I/O), writethrough (to use the host cache but report completion to

    the guest only when the host has committed the changes to disk) or

    writeback (to use the host cache and report completion as soon as

    the data is in the host cache). Note that there are special

    considerations for the cache mode depending on version of KVM used

    and disk type (always raw file under Ganeti), please refer to the

    KVM documentation for more details.

security\_model

    Valid for the KVM hypervisor.

    The security model for kvm. Currently one of "none", "user" or

    "pool". Under "none", the default, nothing is done and instances

    are run as the Ganeti daemon user (normally root).

    Under "user" kvm will drop privileges and become the user specified

    by the security\_domain parameter.

    Under "pool" a global cluster pool of users will be used, making

    sure no two instances share the same user on the same node. (this

    mode is not implemented yet)

security\_domain

    Valid for the KVM hypervisor.

    Under security model "user" the username to run the instance under.

    It must be a valid username existing on the host.

    Cannot be set under security model "none" or "pool".

kvm\_flag

    Valid for the KVM hypervisor.

    If "enabled" the -enable-kvm flag is passed to kvm. If "disabled"

    -disable-kvm is passed. If unset no flag is passed, and the default

    running mode for your kvm binary will be used.

mem\_path

    Valid for the KVM hypervisor.

    This option passes the -mem-path argument to kvm with the path (on

    the node) to the mount point of the hugetlbfs file system, along

    with the -mem-prealloc argument too.

use\_chroot

    Valid for the KVM hypervisor.

    This boolean option determines wether to run the KVM instance in a

    chroot directory.

    If it is set to ``true``, an empty directory is created before

    starting the instance and its path is passed via the -chroot flag

    to kvm. The directory is removed when the instance is stopped.

    It is set to ``false`` by default.

migration\_downtime

    Valid for the KVM hypervisor.

    The maximum amount of time (in ms) a KVM instance is allowed to be

    frozen during a live migration, in order to copy dirty memory

    pages. Default value is 30ms, but you may need to increase this

    value for busy instances.

    This option is only effective with kvm versions >= 87 and qemu-kvm

    versions >= 0.11.0.

cpu\_mask

    Valid for the LXC hypervisor.

    The processes belonging to the given instance are only scheduled on

    the specified CPUs.

    The parameter format is a comma-separated list of CPU IDs or CPU ID

    ranges. The ranges are defined by a lower and higher boundary,

    separated by a dash. The boundaries are inclusive.

usb\_mouse

    Valid for the KVM hypervisor.

    This option specifies the usb mouse type to be used. It can be

    "mouse" or "tablet". When using VNC it's recommended to set it to

    "tablet".

The ``--iallocator`` option specifies the instance allocator plugin

to use. If you pass in this option the allocator will select nodes

for this instance automatically, so you don't need to pass them

with the ``-n`` option. For more information please refer to the

instance allocator documentation.

The ``-t`` options specifies the disk layout type for the instance.

The available choices are:

diskless

    This creates an instance with no disks. Its useful for testing only

    (or other special cases).

file

    Disk devices will be regular files.

plain

    Disk devices will be logical volumes.

drbd

    Disk devices will be drbd (version 8.x) on top of lvm volumes.

The optional second value of the ``--node`` is used for the drbd

template type and specifies the remote node.

If you do not want gnt-instance to wait for the disk mirror to be

synced, use the ``--no-wait-for-sync`` option.

The ``--file-storage-dir`` specifies the relative path under the

cluster-wide file storage directory to store file-based disks. It is

useful for having different subdirectories for different

instances. The full path of the directory where the disk files are

stored will consist of cluster-wide file storage directory + optional

subdirectory + instance name. Example:

``@RPL_FILE_STORAGE_DIR@``*/mysubdir/instance1.example.com*. This

option is only relevant for instances using the file storage backend.

The ``--file-driver`` specifies the driver to use for file-based

disks. Note that currently these drivers work with the xen

hypervisor only. This option is only relevant for instances using

the file storage backend. The available choices are:

loop

    Kernel loopback driver. This driver uses loopback devices to access

    the filesystem within the file. However, running I/O intensive

    applications in your instance using the loop driver might result in

    slowdowns. Furthermore, if you use the loopback driver consider

    increasing the maximum amount of loopback devices (on most systems

    it's 8) using the max\_loop param.

blktap

    The blktap driver (for Xen hypervisors). In order to be able to use

    the blktap driver you should check if the 'blktapctrl' user space

    disk agent is running (usually automatically started via xend).

    This user-level disk I/O interface has the advantage of better

    performance. Especially if you use a network file system (e.g. NFS)

    to store your instances this is the recommended choice.

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**.

Example::

    # gnt-instance add -t file --disk 0:size=30g -B memory=512 -o debian-etch \

      -n node1.example.com --file-storage-dir=mysubdir instance1.example.com

    # gnt-instance add -t plain --disk 0:size=30g -B memory=512 -o debian-etch \

      -n node1.example.com instance1.example.com

    # gnt-instance add -t plain --disk 0:size=30g --disk 1:size=100g,vg=san \

      -B memory=512 -o debian-etch -n node1.example.com instance1.example.com

    # gnt-instance add -t drbd --disk 0:size=30g -B memory=512 -o debian-etch \

      -n node1.example.com:node2.example.com instance2.example.com

BATCH-CREATE

^^^^^^^^^^^^

**batch-create** {instances\_file.json}

This command (similar to the Ganeti 1.2 **batcher** tool) submits

multiple instance creation jobs based on a definition file. The

instance configurations do not encompass all the possible options

for the **add** command, but only a subset.

The instance file should be a valid-formed JSON file, containing a

dictionary with instance name and instance parameters. The accepted

parameters are:

disk\_size

    The size of the disks of the instance.

disk\_template

    The disk template to use for the instance, the same as in the

    **add** command.

backend

    A dictionary of backend parameters.

hypervisor

    A dictionary with a single key (the hypervisor name), and as value

    the hypervisor options. If not passed, the default hypervisor and

    hypervisor options will be inherited.

mac, ip, mode, link

    Specifications for the one NIC that will be created for the

    instance. 'bridge' is also accepted as a backwards compatibile

    key.

nics

    List of nics that will be created for the instance. Each entry

    should be a dict, with mac, ip, mode and link as possible keys.

    Please don't provide the "mac, ip, mode, link" parent keys if you

    use this method for specifying nics.

primary\_node, secondary\_node

    The primary and optionally the secondary node to use for the

    instance (in case an iallocator script is not used).

iallocator

    Instead of specifying the nodes, an iallocator script can be used

    to automatically compute them.

start

    whether to start the instance

ip\_check

    Skip the check for already-in-use instance; see the description in

    the **add** command for details.

name\_check

    Skip the name check for instances; see the description in the

    **add** command for details.

file\_storage\_dir, file\_driver

    Configuration for the file disk type, see the **add** command for

    details.

A simple definition for one instance can be (with most of the

parameters taken from the cluster defaults)::

    {

      "instance3": {

        "template": "drbd",

        "os": "debootstrap",

        "disk_size": ["25G"],

        "iallocator": "dumb"

      },

      "instance5": {

        "template": "drbd",

        "os": "debootstrap",

        "disk_size": ["25G"],

        "iallocator": "dumb",

        "hypervisor": "xen-hvm",

        "hvparams": {"acpi": true},

        "backend": {"memory": 512}

      }

    }

The command will display the job id for each submitted instance, as

follows::

    # gnt-instance batch-create instances.json

    instance3: 11224

    instance5: 11225

REMOVE

^^^^^^

**remove** [--ignore-failures] [--shutdown-timeout=*N*] [--submit]

{*instance*}

Remove an instance. This will remove all data from the instance and

there is *no way back*. If you are not sure if you use an instance

again, use **shutdown** first and leave it in the shutdown state

for a while.

The ``--ignore-failures`` option will cause the removal to proceed

even in the presence of errors during the removal of the instance

(e.g. during the shutdown or the disk removal). If this option is

not given, the command will stop at the first error.

The ``--shutdown-timeout`` is used to specify how much time to wait

before forcing the shutdown (e.g. ``xm destroy`` in Xen, killing the

kvm process for KVM, etc.). By default two minutes are given to each

instance to stop.

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**.

Example::

    # gnt-instance remove instance1.example.com

LIST

^^^^

| **list**

| [--no-headers] [--separator=*SEPARATOR*] [--units=*UNITS*]

| [-o *[+]FIELD,...*] [--roman] [instance...]

Shows the currently configured instances with memory usage, disk

usage, the node they are running on, and their run status.

The ``--no-headers`` option will skip the initial header line. The

``--separator`` option takes an argument which denotes what will be

used between the output fields. Both these options are to help

scripting.

The units used to display the numeric values in the output varies,

depending on the options given. By default, the values will be

formatted in the most appropriate unit. If the ``--separator``

option is given, then the values are shown in mebibytes to allow

parsing by scripts. In both cases, the ``--units`` option can be

used to enforce a given output unit.

The ``--roman`` option allows latin people to better understand the

cluster instances' status.

The ``-o`` option takes a comma-separated list of output fields.

The available fields and their meaning are:

name

    the instance name

os

    the OS of the instance

pnode

    the primary node of the instance

snodes

    comma-separated list of secondary nodes for the instance; usually

    this will be just one node

admin\_state

    the desired state of the instance (either "yes" or "no" denoting

    the instance should run or not)

disk\_template

    the disk template of the instance

oper\_state

    the actual state of the instance; can be one of the values

    "running", "stopped", "(node down)"

status

    combined form of admin\_state and oper\_stat; this can be one of:

    ERROR\_nodedown if the node of the instance is down, ERROR\_down if

    the instance should run but is down, ERROR\_up if the instance

    should be stopped but is actually running, ADMIN\_down if the

    instance has been stopped (and is stopped) and running if the

    instance is set to be running (and is running)

oper\_ram

    the actual memory usage of the instance as seen by the hypervisor

oper\_vcpus

    the actual number of VCPUs the instance is using as seen by the

    hypervisor

ip

    the ip address Ganeti recognizes as associated with the first

    instance interface

mac

    the first instance interface MAC address

nic\_mode

    the mode of the first instance NIC (routed or bridged)

nic\_link

    the link of the first instance NIC

sda\_size

    the size of the instance's first disk

sdb\_size

    the size of the instance's second disk, if any

vcpus

    the number of VCPUs allocated to the instance

tags

    comma-separated list of the instances's tags

serial\_no

    the so called 'serial number' of the instance; this is a numeric

    field that is incremented each time the instance is modified, and

    it can be used to track modifications

ctime

    the creation time of the instance; note that this field contains

    spaces and as such it's harder to parse

    if this attribute is not present (e.g. when upgrading from older

    versions), then "N/A" will be shown instead

mtime

    the last modification time of the instance; note that this field

    contains spaces and as such it's harder to parse

    if this attribute is not present (e.g. when upgrading from older

    versions), then "N/A" will be shown instead

uuid

    Show the UUID of the instance (generated automatically by Ganeti)

network\_port

    If the instance has a network port assigned to it (e.g. for VNC

    connections), this will be shown, otherwise - will be displayed.

beparams

    A text format of the entire beparams for the instance. It's more

    useful to select individual fields from this dictionary, see

    below.

disk.count

    The number of instance disks.

disk.size/N

    The size of the instance's Nth disk. This is a more generic form of

    the sda\_size and sdb\_size fields.

disk.sizes

    A comma-separated list of the disk sizes for this instance.

disk\_usage

    The total disk space used by this instance on each of its nodes.

    This is not the instance-visible disk size, but the actual disk

    "cost" of the instance.

nic.mac/N

    The MAC of the Nth instance NIC.

nic.ip/N

    The IP address of the Nth instance NIC.

nic.mode/N

    The mode of the Nth instance NIC

nic.link/N

    The link of the Nth instance NIC

nic.macs

    A comma-separated list of all the MACs of the instance's NICs.

nic.ips

    A comma-separated list of all the IP addresses of the instance's

    NICs.

nic.modes

    A comma-separated list of all the modes of the instance's NICs.

nic.links

    A comma-separated list of all the link parameters of the instance's

    NICs.

nic.count

    The number of instance nics.

hv/*NAME*

    The value of the hypervisor parameter called *NAME*. For details of

    what hypervisor parameters exist and their meaning, see the **add**

    command.

be/memory

    The configured memory for the instance.

be/vcpus

    The configured number of VCPUs for the instance.

be/auto\_balance

    Whether the instance is considered in N+1 checks.

If the value of the option starts with the character ``+``, the new

field(s) will be added to the default list. This allows to quickly

see the default list plus a few other fields, instead of retyping

the entire list of fields.

There is a subtle grouping about the available output fields: all

fields except for ``oper_state``, ``oper_ram``, ``oper_vcpus`` and

``status`` are configuration value and not run-time values. So if

you don't select any of the these fields, the query will be

satisfied instantly from the cluster configuration, without having

to ask the remote nodes for the data. This can be helpful for big

clusters when you only want some data and it makes sense to specify

a reduced set of output fields.

The default output field list is: name, os, pnode, admin\_state,

oper\_state, oper\_ram.

INFO

^^^^

**info** [-s \| --static] [--roman] {--all \| *instance*}

Show detailed information about the given instance(s). This is

different from **list** as it shows detailed data about the

instance's disks (especially useful for the drbd disk template).

If the option ``-s`` is used, only information available in the

configuration file is returned, without querying nodes, making the

operation faster.

Use the ``--all`` to get info about all instances, rather than

explicitly passing the ones you're interested in.

The ``--roman`` option can be used to cause envy among people who

like ancient cultures, but are stuck with non-latin-friendly

cluster virtualization technologies.

MODIFY

^^^^^^

| **modify**

| [-H *HYPERVISOR\_PARAMETERS*]

| [-B *BACKEND\_PARAMETERS*]

| [--net add*[:options]* \| --net remove \| --net *N:options*]

| [--disk add:size=*SIZE*[,vg=*VG*] \| --disk remove \|

|  --disk *N*:mode=*MODE*]

| [-t plain | -t drbd -n *new_secondary*]

| [--os-name=*OS* [--force-variant]]

| [--submit]

| {*instance*}

Modifies the memory size, number of vcpus, ip address, MAC address

and/or nic parameters for an instance. It can also add and remove

disks and NICs to/from the instance. Note that you need to give at

least one of the arguments, otherwise the command complains.

The ``-H`` option specifies hypervisor options in the form of

name=value[,...]. For details which options can be specified, see

the **add** command.

The ``-t`` option will change the disk template of the instance.

Currently only conversions between the plain and drbd disk templates

are supported, and the instance must be stopped before attempting the

conversion. When changing from the plain to the drbd disk template, a

new secondary node must be specified via the ``-n`` option.

The ``--disk add:size=``*SIZE* option adds a disk to the instance. The

optional ``vg=``*VG* option specifies LVM volume group other than default

vg to create disk on. The ``--disk remove`` option will remove the last

disk of the instance. The ``--disk`` *N*``:mode=``*MODE* option will change

the mode of the Nth disk of the instance between read-only (``ro``) and

read-write (``rw``).

The ``--net add:``*options* option will add a new NIC to the

instance. The available options are the same as in the **add** command

(mac, ip, link, mode). The ``--net remove`` will remove the last NIC

of the instance, while the ``--net`` *N*:*options* option will

change the parameters of the Nth instance NIC.

The option ``--os-name`` will change the OS name for the instance

(without reinstallation). In case an OS variant is specified that

is not found, then by default the modification is refused, unless

``--force-variant`` is passed. An invalid OS will also be refused,

unless the ``--force`` option is given.

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**.

All the changes take effect at the next restart. If the instance is

running, there is no effect on the instance.

REINSTALL

^^^^^^^^^

| **reinstall** [-o *os-type*] [--select-os] [-f *force*]

| [--force-multiple]

| [--instance \| --node \| --primary \| --secondary \| --all]

| [-O *OS\_PARAMETERS*] [--submit] {*instance*...}

Reinstalls the operating system on the given instance(s). The

instance(s) must be stopped when running this command. If the

``--os-type`` is specified, the operating system is changed.

The ``--select-os`` option switches to an interactive OS reinstall.

The user is prompted to select the OS template from the list of

available OS templates. OS parameters can be overridden using

``-O``.

Since this is a potentially dangerous command, the user will be

required to confirm this action, unless the ``-f`` flag is passed.

When multiple instances are selected (either by passing multiple

arguments or by using the ``--node``, ``--primary``,

``--secondary`` or ``--all`` options), the user must pass the

``--force-multiple`` options to skip the interactive confirmation.

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**.

RENAME

^^^^^^

| **rename** [--no-ip-check] [--no-name-check] [--submit]

| {*instance*} {*new\_name*}

Renames the given instance. The instance must be stopped when

running this command. The requirements for the new name are the

same as for adding an instance: the new name must be resolvable and

the IP it resolves to must not be reachable (in order to prevent

duplicate IPs the next time the instance is started). The IP test

can be skipped if the ``--no-ip-check`` option is passed.

The ``--no-name-check`` skips the check for the new instance name

via the resolver (e.g. in DNS or /etc/hosts, depending on your

setup). Since the name check is used to compute the IP address, if

you pass this option you must also pass the ``--no-ip-check``

option.

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**.

Starting/stopping/connecting to console

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

STARTUP

^^^^^^^

| **startup**

| [--force] [--ignore-offline]

| [--force-multiple]

| [--instance \| --node \| --primary \| --secondary \| --all \|

| --tags \| --node-tags \| --pri-node-tags \| --sec-node-tags]

| [-H ``key=value...``] [-B ``key=value...``]

| [--submit]

| {*name*...}

Starts one or more instances, depending on the following options.

The four available modes are:

--instance

    will start the instances given as arguments (at least one argument

    required); this is the default selection

--node

    will start the instances who have the given node as either primary

    or secondary

--primary

    will start all instances whose primary node is in the list of nodes

    passed as arguments (at least one node required)

--secondary

    will start all instances whose secondary node is in the list of

    nodes passed as arguments (at least one node required)

--all

    will start all instances in the cluster (no arguments accepted)

--tags

    will start all instances in the cluster with the tags given as

    arguments

--node-tags

    will start all instances in the cluster on nodes with the tags

    given as arguments

--pri-node-tags

    will start all instances in the cluster on primary nodes with the

    tags given as arguments

--sec-node-tags

    will start all instances in the cluster on secondary nodes with the

    tags given as arguments

Note that although you can pass more than one selection option, the

last one wins, so in order to guarantee the desired result, don't

pass more than one such option.

Use ``--force`` to start even if secondary disks are failing.

``--ignore-offline`` can be used to ignore offline primary nodes

and mark the instance as started even if the primary is not

available.

The ``--force-multiple`` will skip the interactive confirmation in

the case the more than one instance will be affected.

The ``-H`` and ``-B`` options specify temporary hypervisor and

backend parameters that can be used to start an instance with

modified parameters. They can be useful for quick testing without

having to modify an instance back and forth, e.g.::

    # gnt-instance start -H root_args="single" instance1

    # gnt-instance start -B memory=2048 instance2

The first form will start the instance instance1 in single-user

mode, and the instance instance2 with 2GB of RAM (this time only,

unless that is the actual instance memory size already). Note that

the values override the instance parameters (and not extend them):

an instance with "root\_args=ro" when started with -H

root\_args=single will result in "single", not "ro single".

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**.

Example::

    # gnt-instance start instance1.example.com

    # gnt-instance start --node node1.example.com node2.example.com

    # gnt-instance start --all

SHUTDOWN

^^^^^^^^

| **shutdown**

| [--timeout=*N*]

| [--force-multiple] [--ignore-offline]

| [--instance \| --node \| --primary \| --secondary \| --all \|

| --tags \| --node-tags \| --pri-node-tags \| --sec-node-tags]

| [--submit]

| {*name*...}

Stops one or more instances. If the instance cannot be cleanly

stopped during a hardcoded interval (currently 2 minutes), it will

forcibly stop the instance (equivalent to switching off the power

on a physical machine).

The ``--timeout`` is used to specify how much time to wait before

forcing the shutdown (e.g. ``xm destroy`` in Xen, killing the kvm

process for KVM, etc.). By default two minutes are given to each

instance to stop.

The ``--instance``, ``--node``, ``--primary``, ``--secondary``,

``--all``, ``--tags``, ``--node-tags``, ``--pri-node-tags`` and

``--sec-node-tags`` options are similar as for the **startup**

command and they influence the actual instances being shutdown.

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**.

``--ignore-offline`` can be used to ignore offline primary nodes

and force the instance to be marked as stopped. This option should

be used with care as it can lead to an inconsistent cluster state.

Example::

    # gnt-instance shutdown instance1.example.com

    # gnt-instance shutdown --all

REBOOT

^^^^^^

| **reboot**

| [--type=*REBOOT-TYPE*]

| [--ignore-secondaries]

| [--shutdown-timeout=*N*]

| [--force-multiple]

| [--instance \| --node \| --primary \| --secondary \| --all \|

| --tags \| --node-tags \| --pri-node-tags \| --sec-node-tags]

| [--submit]

| [*name*...]

Reboots one or more instances. The type of reboot depends on the

value of ``--type``. A soft reboot does a hypervisor reboot, a hard

reboot does a instance stop, recreates the hypervisor config for

the instance and starts the instance. A full reboot does the

equivalent of **gnt-instance shutdown && gnt-instance startup**.

The default is hard reboot.

For the hard reboot the option ``--ignore-secondaries`` ignores

errors for the secondary node while re-assembling the instance

disks.

The ``--instance``, ``--node``, ``--primary``, ``--secondary``,

``--all``, ``--tags``, ``--node-tags``, ``--pri-node-tags`` and

``--sec-node-tags`` options are similar as for the **startup**

command and they influence the actual instances being rebooted.

The ``--shutdown-timeout`` is used to specify how much time to wait

before forcing the shutdown (xm destroy in xen, killing the kvm

process, for kvm). By default two minutes are given to each

instance to stop.

The ``--force-multiple`` will skip the interactive confirmation in

the case the more than one instance will be affected.

Example::

    # gnt-instance reboot instance1.example.com

    # gnt-instance reboot --type=full instance1.example.com

CONSOLE

^^^^^^^

**console** [--show-cmd] {*instance*}

Connects to the console of the given instance. If the instance is

not up, an error is returned. Use the ``--show-cmd`` option to

display the command instead of executing it.

For HVM instances, this will attempt to connect to the serial

console of the instance. To connect to the virtualized "physical"

console of a HVM instance, use a VNC client with the connection

info from the **info** command.

Example::

    # gnt-instance console instance1.example.com

Disk management

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

REPLACE-DISKS

^^^^^^^^^^^^^

**replace-disks** [--submit] [--early-release] {-p} [--disks *idx*]

{*instance*}

**replace-disks** [--submit] [--early-release] {-s} [--disks *idx*]

{*instance*}

**replace-disks** [--submit] [--early-release] {--iallocator *name*

\| --new-secondary *NODE*} {*instance*}

**replace-disks** [--submit] [--early-release] {--auto}

{*instance*}

This command is a generalized form for replacing disks. It is

currently only valid for the mirrored (DRBD) disk template.

The first form (when passing the ``-p`` option) will replace the

disks on the primary, while the second form (when passing the

``-s`` option will replace the disks on the secondary node. For

these two cases (as the node doesn't change), it is possible to

only run the replace for a subset of the disks, using the option

``--disks`` which takes a list of comma-delimited disk indices

(zero-based), e.g. 0,2 to replace only the first and third disks.

The third form (when passing either the ``--iallocator`` or the

``--new-secondary`` option) is designed to change secondary node of

the instance. Specifying ``--iallocator`` makes the new secondary

be selected automatically by the specified allocator plugin,

otherwise the new secondary node will be the one chosen manually

via the ``--new-secondary`` option.

The fourth form (when using ``--auto``) will automatically

determine which disks of an instance are faulty and replace them

within the same node. The ``--auto`` option works only when an

instance has only faulty disks on either the primary or secondary

node; it doesn't work when both sides have faulty disks.

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**.

The ``--early-release`` changes the code so that the old storage on

secondary node(s) is removed early (before the resync is completed)

and the internal Ganeti locks for the current (and new, if any)

secondary node are also released, thus allowing more parallelism in

the cluster operation. This should be used only when recovering

from a disk failure on the current secondary (thus the old storage

is already broken) or when the storage on the primary node is known

to be fine (thus we won't need the old storage for potential

recovery).

Note that it is not possible to select an offline or drained node

as a new secondary.

ACTIVATE-DISKS

^^^^^^^^^^^^^^

**activate-disks** [--submit] [--ignore-size] {*instance*}

Activates the block devices of the given instance. If successful,

the command will show the location and name of the block devices::

    node1.example.com:disk/0:/dev/drbd0

    node1.example.com:disk/1:/dev/drbd1

In this example, *node1.example.com* is the name of the node on

which the devices have been activated. The *disk/0* and *disk/1*

are the Ganeti-names of the instance disks; how they are visible

inside the instance is hypervisor-specific. */dev/drbd0* and

*/dev/drbd1* are the actual block devices as visible on the node.

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**.

The ``--ignore-size`` option can be used to activate disks ignoring

the currently configured size in Ganeti. This can be used in cases

where the configuration has gotten out of sync with the real-world

(e.g. after a partially-failed grow-disk operation or due to

rounding in LVM devices). This should not be used in normal cases,

but only when activate-disks fails without it.

Note that it is safe to run this command while the instance is

already running.

DEACTIVATE-DISKS

^^^^^^^^^^^^^^^^

**deactivate-disks** [--submit] {*instance*}

De-activates the block devices of the given instance. Note that if

you run this command for an instance with a drbd disk template,

while it is running, it will not be able to shutdown the block

devices on the primary node, but it will shutdown the block devices

on the secondary nodes, thus breaking the replication.

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**.

GROW-DISK

^^^^^^^^^

**grow-disk** [--no-wait-for-sync] [--submit] {*instance*} {*disk*}

{*amount*}

Grows an instance's disk. This is only possible for instances

having a plain or drbd disk template.

Note that this command only change the block device size; it will

not grow the actual filesystems, partitions, etc. that live on that

disk. Usually, you will need to:

#. use **gnt-instance grow-disk**

#. reboot the instance (later, at a convenient time)

#. use a filesystem resizer, such as ext2online(8) or

   xfs\_growfs(8) to resize the filesystem, or use fdisk(8) to change

   the partition table on the disk

The *disk* argument is the index of the instance disk to grow. The

*amount* argument is given either as a number (and it represents

the amount to increase the disk with in mebibytes) or can be given

similar to the arguments in the create instance operation, with a

suffix denoting the unit.

Note that the disk grow operation might complete on one node but

fail on the other; this will leave the instance with

different-sized LVs on the two nodes, but this will not create

problems (except for unused space).

If you do not want gnt-instance to wait for the new disk region to

be synced, use the ``--no-wait-for-sync`` option.

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**.

Example (increase the first disk for instance1 by 16GiB)::

    # gnt-instance grow-disk instance1.example.com 0 16g

Also note that disk shrinking is not supported; use

**gnt-backup export** and then **gnt-backup import** to reduce the

disk size of an instance.

RECREATE-DISKS

^^^^^^^^^^^^^^

**recreate-disks** [--submit] [--disks=``indices``] {*instance*}

Recreates the disks of the given instance, or only a subset of the

disks (if the option ``disks`` is passed, which must be a

comma-separated list of disk indices, starting from zero).

Note that this functionality should only be used for missing disks;

if any of the given disks already exists, the operation will fail.

While this is suboptimal, recreate-disks should hopefully not be

needed in normal operation and as such the impact of this is low.

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**.

Recovery

~~~~~~~~

FAILOVER

^^^^^^^^

**failover** [-f] [--ignore-consistency] [--shutdown-timeout=*N*]

[--submit] {*instance*}

Failover will fail the instance over its secondary node. This works

only for instances having a drbd disk template.

Normally the failover will check the consistency of the disks

before failing over the instance. If you are trying to migrate

instances off a dead node, this will fail. Use the

``--ignore-consistency`` option for this purpose. Note that this

option can be dangerous as errors in shutting down the instance

will be ignored, resulting in possibly having the instance running

on two machines in parallel (on disconnected DRBD drives).

The ``--shutdown-timeout`` is used to specify how much time to wait

before forcing the shutdown (xm destroy in xen, killing the kvm

process, for kvm). By default two minutes are given to each

instance to stop.

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**.

Example::

    # gnt-instance failover instance1.example.com

MIGRATE

^^^^^^^

**migrate** [-f] {--cleanup} {*instance*}

**migrate** [-f] [--non-live] [--migration-mode=live\|non-live]

{*instance*}

Migrate will move the instance to its secondary node without

shutdown. It only works for instances having the drbd8 disk

template type.

The migration command needs a perfectly healthy instance, as we

rely on the dual-master capability of drbd8 and the disks of the

instance are not allowed to be degraded.

The ``--non-live`` and ``--migration-mode=non-live`` options will

switch (for the hypervisors that support it) between a "fully live"

(i.e. the interruption is as minimal as possible) migration and one

in which the instance is frozen, its state saved and transported to

the remote node, and then resumed there. This all depends on the

hypervisor support for two different methods. In any case, it is

not an error to pass this parameter (it will just be ignored if the

hypervisor doesn't support it). The option

``--migration-mode=live`` option will request a fully-live

migration. The default, when neither option is passed, depends on

the hypervisor parameters (and can be viewed with the

**gnt-cluster info** command).

If the ``--cleanup`` option is passed, the operation changes from

migration to attempting recovery from a failed previous migration.

In this mode, Ganeti checks if the instance runs on the correct

node (and updates its configuration if not) and ensures the

instances's disks are configured correctly. In this mode, the

``--non-live`` option is ignored.

The option ``-f`` will skip the prompting for confirmation.

Example (and expected output)::

    # gnt-instance migrate instance1

    Migrate will happen to the instance instance1. Note that migration is

    **experimental** in this version. This might impact the instance if

    anything goes wrong. Continue?

    y/[n]/?: y

    * checking disk consistency between source and target

    * ensuring the target is in secondary mode

    * changing disks into dual-master mode

     - INFO: Waiting for instance instance1 to sync disks.

     - INFO: Instance instance1's disks are in sync.

    * migrating instance to node2.example.com

    * changing the instance's disks on source node to secondary

     - INFO: Waiting for instance instance1 to sync disks.

     - INFO: Instance instance1's disks are in sync.

    * changing the instance's disks to single-master

    #

MOVE

^^^^

**move** [-f] [-n *node*] [--shutdown-timeout=*N*] [--submit]

{*instance*}

Move will move the instance to an arbitrary node in the cluster.

This works only for instances having a plain or file disk

template.

Note that since this operation is done via data copy, it will take

a long time for big disks (similar to replace-disks for a drbd

instance).

The ``--shutdown-timeout`` is used to specify how much time to wait

before forcing the shutdown (e.g. ``xm destroy`` in XEN, killing the

kvm process for KVM, etc.). By default two minutes are given to each

instance to stop.

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**.

Example::

    # gnt-instance move -n node3.example.com instance1.example.com

TAGS

~~~~

ADD-TAGS

^^^^^^^^

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

Add tags to the given instance. 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.

LIST-TAGS

^^^^^^^^^

**list-tags** {*instancename*}

List the tags of the given instance.

REMOVE-TAGS

^^^^^^^^^^^

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

Remove tags from the given instance. If any of the tags are not

existing on the node, 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.