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 OpenStack Images 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.

Launch an instance

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

• To select the volume to from which to launch, launch an instance from an arbitrary image on the volume. The 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, fylle 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 from KVM images or xvda for Xen images.

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

1. Log in to the dashboard, choose a project and click Images.
   The dashboard shows the images that have been uploaded to OpenStack Image Service and are available for this project.
2. Select an image and click Launch.
3. in the Launch Instance dialog box, specify the following values:
   
   Details tab
   Availability ZoneBy 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.Instance NameAssign a name to the virtual machine. NoteThe name you assign here becomes the initial host name of the server.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.FlavorSpecify the size of the instance to launch. NoteThe 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 Minimum RAM (MB) field as 2048, then on selecting the image, the default flavor is m1.small.Instance CountTo launch multiple instances, enter a value greater than 1. The default is 1.Instance Boot SourceYour options are:Boot from imageIf you choose this option, a new field for Image Name displays. You can select the image from the list.Boot from snapshotIf you choose this option, a new field for Instance Snapshot displays. You can select the snapshot from the list.Boot from volumeIf you choose this option, a new field for 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 Device Size and Device Name for your volume. Click the Delete on Terminate option to delete the volume on terminating 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 Volume Snapshot from a list and adding a Device Name for your volume. Click the Delete on Terminate option to delete the volume on terminating the instance.Since you are launching an instance from an image, Boot from image is chosen by default.Image NameThis field changes based on your previous selection. Since you have chosen to launch an instance using an image, the Image Name field displays. Select the image name from the dropdown list.
   
   Access & Security tab
   KeypairSpecify 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 e key pair to launch the instance. Security Group 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 noy created any security groups, you can assign only the default security group to the instance.
   
   Networking tab
   Selected Networks to add a network to the instance, click the + in the Available Networks fields.
   
   Post-Creation tab
   Customization Script specify a customization script that runs efter your instance launches
   
   Advanced Options tab
   Disk Partition select the type of disk partition from the dropdown list: Automatic entire disk is single partition and automatically resizes. Manual faster build times but requires manual partitioning.
   
   
   
4. Click Launch.

The Instances tab shows the instance's name, it's private and public IP addresses, size, status, task, and power state.

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 pining the instance is not possible without an ICMP rule configured.

Connect to your instance by using SSH

To use SSH to connect to your instance, you use the downloaded keypair file.

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

1. Copy the IP address for the instance.
2. Use the ssh command to make a secure connection to the instance. For example:
   $ ssh -i MyKey.pem ubuntu@10.0.0.2
3. At the prompt, type yes.

Track usage for instances

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

1. Log in to the dashboard, choose a project, and click Overview.
2. To query the instances usage for a month, select a month and click Submit.
3. To download a summary, click Download CSV Summary.
   
   

Create an instance snapshots

1. Log in to the dashboard, choose a project, and click Instances.
2. Select the instances from which to create a snapshot.
3. In the Action column, click Create Snapshot.
4. In the Create Snapshot dialog box, enter a name for the snapshot, and click Create Snapshot.
   The Images category shows the instance snapshot

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

Manage an instance

1. Log in to the dashboard, choose a project, and click Instances.
2. Select in instance.
3. In the More list in the Action 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.

Except where otherwise noted, this document is licensed under Creative Commons Attribution 3.0 License
Changes were made based on the original Openstack User guide