===========================
Launch and manage instances
===========================

Instances are virtual machines that run inside the cloud.
You can launch an instance from the following sources:

* Images uploaded to the Image service.

* Image that you have copied to a persistent volume. The instance
  launches from the volume, which is provided by the ``cinder-volume``
  API through iSCSI.

* Instance snapshot that you took.

Launch an instance
~~~~~~~~~~~~~~~~~~

#. Log in to the dashboard.

#. Select the appropriate project from the drop down menu at the top left.

#. On the :guilabel:`Project` tab, open the :guilabel:`Compute` tab and
   click :guilabel:`Instances` category.

   The dashboard shows the instances with its name, its private and
   floating IP addresses, size, status, task, power state, and so on.

#. Click :guilabel:`Launch Instance`.

#. In the :guilabel:`Launch Instance` dialog box, specify the following values:

   :guilabel:`Details` tab

   Instance Name
      Assign a name to the virtual machine.

      .. note::

         The name you assign here becomes the initial host name of the server.
         If the name is longer than 63 characters, the Compute service
         truncates it automatically to ensure dnsmasq works correctly.

         After the server is built, if you change the server name in the API
         or change the host name directly, the names are not updated in the
         dashboard.

         Server names are not guaranteed to be unique when created so you
         could have two instances with the same host name.

   Description
      You can assign a brief description of the virtual machine.

   Availability Zone
      By default, this value is set to the availability zone given by the
      cloud provider (for example, ``us-west`` or ``apac-south``). For some
      cases, it could be ``nova``.

   Count
      To launch multiple instances, enter a value greater than ``1``. The
      default is ``1``.

   :guilabel:`Source` tab

   Instance Boot Source
      Your options are:

      Boot from image
          If you choose this option, a new field for :guilabel:`Image Name`
          displays. You can select the image from the list.

      Boot from snapshot
          If you choose this option, a new field for :guilabel:`Instance
          Snapshot` displays. You can select the snapshot from the list.

      Boot from volume
          If you choose this option, a new field for :guilabel:`Volume`
          displays. You can select the volume from the list.

      Boot from image (creates a new volume)
          With this option, you can boot from an image and create a volume
          by entering the :guilabel:`Device Size` and :guilabel:`Device
          Name` for your volume. Click the :guilabel:`Delete Volume on
          Instance Delete` option to delete the volume on deleting the
          instance.

      Boot from volume snapshot (creates a new volume)
          Using this option, you can boot from a volume snapshot and create
          a new volume by choosing :guilabel:`Volume Snapshot` from a list
          and adding a :guilabel:`Device Name` for your volume. Click the
          :guilabel:`Delete Volume on Instance Delete` option to delete the
          volume on deleting the instance.

   Image Name
      This field changes based on your previous selection. If you have
      chosen to launch an instance using an image, the :guilabel:`Image Name`
      field displays. Select the image name from the dropdown list.

   Instance Snapshot
      This field changes based on your previous selection. If you have
      chosen to launch an instance using a snapshot, the
      :guilabel:`Instance Snapshot` field displays.
      Select the snapshot name from the dropdown list.

   Volume
      This field changes based on your previous selection. If you have
      chosen to launch an instance using a volume, the :guilabel:`Volume`
      field displays. Select the volume name from the dropdown list.
      If you want to delete the volume on instance delete,
      check the :guilabel:`Delete Volume on Instance Delete` option.

   :guilabel:`Flavor` tab

   Flavor
      Specify the size of the instance to launch.

      .. note::

         The flavor is selected based on the size of the image selected
         for launching an instance. For example, while creating an image, if
         you have entered the value in the :guilabel:`Minimum RAM (MB)` field
         as 2048, then on selecting the image, the default flavor is
         ``m1.small``.

   :guilabel:`Networks` tab

   Selected Networks
      To add a network to the instance, click the :guilabel:`+` in the
      :guilabel:`Available` field.

   :guilabel:`Network Ports` tab

   Ports
      Activate the ports that you want to assign to the instance.

   :guilabel:`Security Groups` tab

   Security Groups
      Activate the security groups that you want to assign to the instance.

      Security groups are a kind of cloud firewall that define which
      incoming network traffic is forwarded to instances.

      If you have not created any security groups, you can assign
      only the default security group to the instance.

   :guilabel:`Key Pair` tab

   Key Pair
      Specify a key pair.

      If the image uses a static root password or a static key set
      (neither is recommended), you do not need to provide a key pair
      to launch the instance.

   :guilabel:`Configuration` tab

   Customization Script Source
      Specify a customization script that runs after your instance
      launches.

   :guilabel:`Metadata` tab

   Available Metadata
      Add Metadata items to your instance.

#. Click :guilabel:`Launch Instance`.

   The instance starts on a compute node in the cloud.

.. note::

   If you did not provide a key pair, security groups, or rules, users
   can access the instance only from inside the cloud through VNC. Even
   pinging the instance is not possible without an ICMP rule configured.

You can also launch an instance from the :guilabel:`Images` or
:guilabel:`Volumes` category when you launch an instance from
an image or a volume respectively.

When you launch an instance from an image, OpenStack creates a local
copy of the image on the compute node where the instance starts.

For details on creating images, see `Creating images
manually <https://docs.openstack.org/image-guide/create-images-manually.html>`_
in the *OpenStack Virtual Machine Image Guide*.

When you launch an instance from a volume, note the following steps:

* To select the volume from which to launch, launch an instance from
  an arbitrary image on the volume. The arbitrary image that you select
  does not boot. Instead, it is replaced by the image on the volume that
  you choose in the next steps.

  To boot a Xen image from a volume, the image you launch in must be
  the same type, fully virtualized or paravirtualized, as the one on
  the volume.

* Select the volume or volume snapshot from which to boot. Enter a
  device name. Enter ``vda`` for KVM images or ``xvda`` for Xen images.

.. note::

   When running QEMU without support for the hardware virtualization, set
   ``cpu_mode="none"`` alongside ``virt_type=qemu`` in
   ``/etc/nova/nova-compute.conf`` to solve the following error:

   .. code-block:: console

      libvirtError: unsupported configuration: CPU mode 'host-model'
      for ``x86_64`` qemu domain on ``x86_64`` host is not supported by hypervisor

Connect to your instance by using SSH
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

To connect to your instance via SSH, use the downloaded key pair file.

.. note::

   The user name is ``ubuntu`` for the Ubuntu cloud images on TryStack.

#. Copy the IP address for your instance.

#. Use the :command:`ssh` command to make a secure connection to the instance.
   For example:

   .. code-block:: console

      $ ssh -i MyKey.pem ubuntu@10.0.0.2

#. At the prompt, type ``yes``.

It is also possible to SSH into an instance without an SSH keypair, if the
administrator has enabled root password injection.  For more information
about root password injection, see `Injecting the administrator password
<https://docs.openstack.org/nova/latest/admin/admin-password-injection.html>`_
in the *OpenStack Administrator Guide*.

Track usage for instances
~~~~~~~~~~~~~~~~~~~~~~~~~

You can track usage for instances for each project. You can track costs
per month by showing meters like number of vCPUs, disks, RAM, and
uptime for all your instances.

#. Log in to the dashboard.

#. Select the appropriate project from the drop down menu at the top left.

#. On the :guilabel:`Project` tab, open the :guilabel:`Compute` tab and
   click :guilabel:`Overview` category.

#. To query the instance usage for a month, select a month and click
   :guilabel:`Submit`.

#. To download a summary, click :guilabel:`Download CSV Summary`.

Create an instance snapshot
~~~~~~~~~~~~~~~~~~~~~~~~~~~

#. Log in to the dashboard.

#. Select the appropriate project from the drop down menu at the top left.

#. On the :guilabel:`Project` tab, open the :guilabel:`Compute` tab and
   click the :guilabel:`Instances` category.

#. Select the instance from which to create a snapshot.

#. In the actions column, click :guilabel:`Create Snapshot`.

#. In the :guilabel:`Create Snapshot` dialog box, enter a name for the
   snapshot, and click :guilabel:`Create Snapshot`.

   The :guilabel:`Images` category shows the instance snapshot.

To launch an instance from the snapshot, select the snapshot and click
:guilabel:`Launch`. Proceed with launching an instance.

Manage an instance
~~~~~~~~~~~~~~~~~~

#. Log in to the dashboard.

#. Select the appropriate project from the drop down menu at the top left.

#. On the :guilabel:`Project` tab, open the :guilabel:`Compute` tab and
   click :guilabel:`Instances` category.

#. Select an instance.

#. In the menu list in the actions column, select the state.

   You can resize or rebuild an instance. You can also choose to view
   the instance console log, edit instance or the security groups.
   Depending on the current state of the instance, you can pause,
   resume, suspend, soft or hard reboot, or terminate it.
