as 'dc'.
For KVM the boot order is either "floppy", "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.
+ "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. Also note
+ that if you have set the ``kernel_path`` option, that will be used
+ for booting, and this setting will be silently ignored.
blockdev\_prefix
Valid for the Xen HVM and PVM hypervisors.
Enables or disables passing mouse events via SPICE vdagent.
+cpu\_type
+ Valid for the KVM hypervisor.
+
+ This parameter determines the emulated cpu for the instance. If this
+ parameter is empty (which is the default configuration), it will not
+ be passed to KVM.
+
+ Be aware of setting this parameter to ``"host"`` if you have nodes
+ with different CPUs from each other. Live migration may stop working
+ in this situation.
+
+ For more information please refer to the KVM manual.
+
acpi
Valid for the Xen HVM and KVM hypervisors.
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.
+ 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 (and the boot will be done accordingly to
+ ``boot_order``).
kernel\_args
Valid for the Xen PVM and KVM hypervisors.
versions >= 0.11.0.
cpu\_mask
- Valid for the LXC hypervisor.
+ Valid for the Xen, KVM and LXC hypervisors.
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.
+ The format of the mask can be given in three forms. First, the word
+ "all", which signifies the common case where all VCPUs can live on
+ any CPU, based on the hypervisor's decisions.
+
+ Second, 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, and the boundaries are inclusive. In this form, all VCPUs of
+ the instance will be mapped on the selected list of CPUs. Example:
+ ``0-2,5``, mapping all VCPUs (no matter how many) onto physical CPUs
+ 0, 1, 2 and 5.
+
+ The last form is used for explicit control of VCPU-CPU pinnings. In
+ this form, the list of VCPU mappings is given as a colon (:)
+ separated list, whose elements are the possible values for the
+ second or first form above. In this form, the number of elements in
+ the colon-separated list _must_ equal the number of VCPUs of the
+ instance.
+
+ Example::
+
+ # Map the entire instance to CPUs 0-2
+ gnt-instance modify -H cpu_mask=0-2 my-inst
+
+ # Map vCPU 0 to physical CPU 1 and vCPU 1 to CPU 3 (assuming 2 vCPUs)
+ gnt-instance modify -H cpu_mask=1:3 my-inst
+
+ # Pin vCPU 0 to CPUs 1 or 2, and vCPU 1 to any CPU
+ gnt-instance modify -H cpu_mask=1-2:all my-inst
+
+ # Pin vCPU 0 to any CPU, vCPU 1 to CPUs 1, 3, 4 or 5, and CPU 2 to
+ # CPU 0 (backslashes for escaping the comma)
+ gnt-instance modify -H cpu_mask=all:1\\,3-5:0 my-inst
+
+ # Pin entire VM to CPU 0
+ gnt-instance modify -H cpu_mask=0 my-inst
+
+ # Turn off CPU pinning (default setting)
+ gnt-instance modify -H cpu_mask=all my-inst
usb\_mouse
Valid for the KVM hypervisor.
``metavg=``*VG* option specifies the volume group for the metadata
device. ``--disk`` *N*``:add,size=``**SIZE** can be used to add a
disk at a specific index. The ``--disk remove`` option will remove the
-last disk of the instance. Use ``--disk ``*N*``:remove`` to remove a
+last disk of the instance. Use ``--disk `` *N*``:remove`` to remove a
disk by its index. 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``).
[\--disks *idx*] {*instance*}
**replace-disks** [\--submit] [\--early-release] [\--ignore-ipolicy]
-{\--iallocator *name* \| \--node *node* } {*instance*}
+{{-I\|\--iallocator} *name* \| \--node *node* } {*instance*}
**replace-disks** [\--submit] [\--early-release] [\--ignore-ipolicy]
{\--auto} {*instance*}
ACTIVATE-DISKS
^^^^^^^^^^^^^^
-**activate-disks** [\--submit] [\--ignore-size] {*instance*}
+**activate-disks** [\--submit] [\--ignore-size] [\--wait-for-sync] {*instance*}
Activates the block devices of the given instance. If successful, the
command will show the location and name of the block devices::
in LVM devices). This should not be used in normal cases, but only
when activate-disks fails without it.
+The ``--wait-for-sync`` option will ensure that the command returns only
+after the instance's disks are synchronised (mostly for DRBD); this can
+be useful to ensure consistency, as otherwise there are no commands that
+can wait until synchronisation is done. However when passing this
+option, the command will have additional output, making it harder to
+parse the disk information.
+
Note that it is safe to run this command while the instance is already
running.
GROW-DISK
^^^^^^^^^
-| **grow-disk** [\--no-wait-for-sync] [\--submit] {*instance*} {*disk*}
-| {*amount*}
+| **grow-disk** [\--no-wait-for-sync] [\--submit] [\--absolute]
+| {*instance*} {*disk*} {*amount*}
Grows an instance's disk. This is only possible for instances having a
plain, drbd or rbd disk template.
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.
+*amount* argument is given as a number which can have a suffix (like the
+disk size in instance create); if the suffix is missing, the value will
+be interpreted as mebibytes.
+
+By default, the *amount* value represents the desired increase in the
+disk size (e.g. an amount of 1G will take a disk of size 3G to 4G). If
+the optional ``--absolute`` parameter is passed, then the *amount*
+argument doesn't represent the delta, but instead the desired final disk
+size (e.g. an amount of 8G will take a disk of size 4G to 8G).
For instances with a drbd template, note that the disk grow operation
might complete on one node but fail on the other; this will leave the
# gnt-instance grow-disk instance1.example.com 0 16g
+Example for increasing the disk size to a certain size::
+
+ # gnt-instance grow-disk --absolute instance1.example.com 0 32g
Also note that disk shrinking is not supported; use **gnt-backup
export** and then **gnt-backup import** to reduce the disk size of an
RECREATE-DISKS
^^^^^^^^^^^^^^
-| **recreate-disks** [\--submit] [-n node1:[node2]]
+| **recreate-disks** [\--submit]
+| [{-n node1:[node2] \| {-I\|\--iallocator *name*}}]
| [\--disk=*N*[:[size=*VAL*][,mode=*ro\|rw*]]] {*instance*}
Recreates all or a subset of disks of the given instance.
has. Note that changing nodes is only allowed when all disks are
replaced, e.g. when no ``--disk`` option is passed.
+Another method of chosing which nodes to place the instance on is by
+using the specified iallocator, passing the ``--iallocator`` option.
+The primary and secondary nodes will be chosen by the specified
+iallocator plugin.
+
See **ganeti(7)** for a description of ``--submit`` and other common
options.
MIGRATE
^^^^^^^
-**migrate** [-f] {\--cleanup} {*instance*}
+| **migrate** [-f] [\--allow-failover] [\--non-live]
+| [\--migration-mode=live\|non-live] [\--ignore-ipolicy]
+| [\--no-runtime-changes] [\--submit]
+| [{-n|\--target-node} *node* \| {-I|\--iallocator} *name*] {*instance*}
-**migrate** [-f] [\--allow-failover] [\--non-live]
-[\--migration-mode=live\|non-live] [\--ignore-ipolicy]
-[\--no-runtime-changes]
-[{-n|\--target-node} *node* \| {-I|\--iallocator} *name*] {*instance*}
+| **migrate** [-f] \--cleanup [\--submit] {*instance*}
Migrate will move the instance to its secondary node without shutdown.
As with failover, it only works for instances having the drbd disk
instance's runtime before migrating it (eg. ballooning an instance
down because the target node doesn't have enough available memory).
+See **ganeti(7)** for a description of ``--submit`` and other common
+options.
+
Example (and expected output)::
# gnt-instance migrate instance1
CHANGE-GROUP
~~~~~~~~~~~~
-**change-group** [\--iallocator *NAME*] [\--to *GROUP*...] {*instance*}
+| **change-group** [\--submit]
+| [\--iallocator *NAME*] [\--to *GROUP*...] {*instance*}
This command moves an instance to another node group. The move is
calculated by an iallocator, either given on the command line or as a
If no specific destination groups are specified using ``--to``, all
groups except the one containing the instance are considered.
+See **ganeti(7)** for a description of ``--submit`` and other common
+options.
+
Example::
# gnt-instance change-group -I hail --to rack2 inst1.example.com