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Launching an Instance from a Snapshot

If you have a snapshot of the root device volume of an instance, you can terminate that instance and then later launch a new instance from the snapshot. This is useful if you don't have the original AMI available to launch new instances from.

To launch a new instance from the snapshot, you register the snapshot and then launch the resulting AMI.

	Important
	Registering a snapshot works only for Linux/UNIX AMIs; although you can register a snapshot to create a Windows AMI, the AMI isn't launchable.

Command Line tools

Use the ec2-register command and specify a block device mapping that maps the root device name of your choice to the snapshot.
The following example specifies the root device as /dev/sda1, and maps it to the snap-12345678 snapshot. The resulting root device volume is the same size as the snapshot, and it will automatically be deleted on instance termination. If you were to specify the block device mapping as /dev/sda1=snap-1234578::false, then the volume would persist on instance termination.
```
PROMPT>  ec2-register -n My_Image_Name -d My_image_description --root-device-name /dev/sda1 -b /dev/sda1=snap-12345678 -aki-12345678
```
The response displays the ID for your new AMI.
```
IMAGE    ami-61a54008
```
The AMI now appears in the list of AMIs that you own. You can view that list in the AWS Management Console, or by using the following command: ec2-describe-images -o self.
Launch an instance of the AMI.
The resulting instance has a root device volume created from the snapshot.

API

Issue the following Query request to register an image.
The example specifies the root device as /dev/sda1, and maps it to the snap-12345678 snapshot. The resulting root device volume is the same size as the snapshot, and it will automatically be deleted on instance termination. You can set DeleteOnTermination to false if you'd rather the volume persist.
```
https://ec2.amazonaws.com/
?Action=RegisterImage
&Name=MyImage
&KernelId=aki-f70657b2
&RamdiskId=ari-ff0d5cba
&RootDeviceName=/dev/sda1
&BlockDeviceMapping.1.DeviceName=/dev/sda1
&BlockDeviceMapping.1.Ebs.SnapshotId=snap-12345678
&...auth parameters...
```
For information about the auth parameters, go to Common Query Parameters in the Amazon Elastic Compute Cloud API Reference.
Following is an example response.
```
<RegisterImageResponse xmlns="http://ec2.amazonaws.com/doc/2012-04-01/">
   <requestId>59dbff89-35bd-4eac-99ed-be587EXAMPLE</requestId> 
   <imageId>ami-61a54008</imageId>
</RegisterImageResponse>
```
The AMI now appears in the list of AMIs that you own. You can view that list by using DescribeImages with Owner=self.
Launch an instance of the AMI.
The resulting instance has a root device volume created from the snapshot.

Document Conventions
Terms of Use

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