Creating Amazon EBS Volumes and Snapshots

Creating an Amazon EBS Volume

To use Amazon EBS, you first create a volume that can be attached to any Amazon EC2 instance within the same availability zone. This example creates an 800 GiB Amazon EBS volume.

To create an Amazon EBS volume

Enter the following command.

PROMPT>  ec2-create-volume --size 800 --zone us-east-1a

Amazon EBS returns information about the volume similar to the following example.

VOLUME vol-4d826724 800 us-east-1a available 2008-02-14T00:00:00+0000

To check whether the volume is ready, use the following command.
```
PROMPT>  ec2-describe-volumes vol-4d826724
```
Amazon EBS returns information about the volume similar to the following example.
```
VOLUME  vol-4d826724 800 us-east-1a  available 2008-07-29T08:49:25+0000 
```

Attaching the Volume to an Instance

This example attaches volume vol-4d826724 to instance i-6058a509 and exposes it as device /dev/sdh.

To attach an Amazon EBS volume

Enter the following command.

PROMPT>  ec2-attach-volume vol-4d826724 -i i-6058a509 -d /dev/sdh

Amazon EBS returns information similar to the following example.

ATTACHMENT vol-4d826724 i-6058a509 /dev/sdh attaching 2008-02-14T00:15:00+0000

Describing Volumes and Instances

After creating Amazon EBS volumes and attaching them to instances, you can list them using the DescribeVolumes and the DescribeInstances operations.

DescribeVolumes returns the volume ID, capacity, status (in-use or available) and creation time of each volume. If the volume is attached, an attachment line shows the volume ID, the instance ID to which the volume is attached, the device name exposed to the instance, its status (attaching, attached, detaching, detached), and when it attached.

DescribeInstances lists volumes that are attached to running instances.

To describe volumes

Enter the following command.

              PROMPT> 
              
                 
              
              ec2-describe-volumes

Amazon EBS returns information about all volumes that you own.

VOLUME vol-4d826724 us-east-1a 800 in-use 2008-02-14T00:00:00+0000
  ATTACHMENT vol-4d826724 i-6058a509 /dev/sdh attached 2008-02-14T00:00:17+0000
  VOLUME vol-50957039 13 us-east-1a available 2008-02-091T00:00:00+0000
  VOLUME vol-6682670f 1 us-east-1a in-use 2008-02-11T12:00:00+0000
  ATTACHMENT vol-6682670f i-69a54000 /dev/sdh attached 2008-02-11T13:56:00+0000

To describe instances

Enter the following command.

              PROMPT> 
              
                 
              
              ec2-describe-instances

Amazon EBS returns information about all running instances and volumes attached to those instances.

RESERVATION  r-e112fc88	416161254515  default
  INSTANCE  i-3b887c52  ami-3fd13456  ec2-67-202-27-216.compute-1.amazonaws.com  domU-12-31-38-00-35-94.compute-1.internal
  running	gsg-keypair  0  m1.small  2007-11-26T13:20:35+0000  vol-4d826724
  RESERVATION  r-e612fc8f	416161254515  default
  INSTANCE  i-21b63c22  ami-3fd13456  ec2-67-202-18-227.compute-1.amazonaws.com	domU-12-31-38-00-39-28.compute-1.internal
  running	gsg-keypair  0  m1.small  2007-11-26T13:21:51+0000  vol-6682670f,vol-50957039

Using an Amazon EBS Volume within an Instance

Inside the instance, the Amazon EBS volume is exposed as a normal block device and can be formatted as any file system and mounted. This example creates an ext3 file system on the Amazon EBS volume and mounts it as /mnt/data-store.

To use an Amazon EBS volume

Enter the following command.

              PROMPT> 
              
                 
              
              yes | mkfs -t ext3 /dev/sdh

Enter the following command.

              PROMPT> 
              
                 
              
              mkdir /mnt/data-store

Enter the following command.

              PROMPT> 
              
                 
              
              mount /dev/sdh /mnt/data-store

Any data written to this file system is written to the Amazon EBS volume and is transparent to applications using the device.

Creating an Amazon EBS Snapshot

After writing data to an Amazon EBS volume, you can periodically create a snapshot of the volume to use as a baseline for new volumes or for data backup.

This example creates a snapshot of the vol-4d826724 Amazon EBS volume using the CreateSnapshot function.

To create a snapshot

Enter the following command.

PROMPT>  ec2-create-snapshot vol-4d826724

Amazon EBS returns information similar to the following example.

SNAPSHOT snap-78a54011 vol-4d826724 pending 2008-02-15T09:03:58+0000

The snapshot occurs asynchronously and the volume's status indicates "pending" until it completes.

	Note
	For information on creating an Amazon EBS volume from a snapshot, refer to the Amazon Elastic Compute Cloud Developer Guide.

Describing Snapshots

This example describes snapshots using the CreateSnapshot function.

To describe snapshots

Enter the following command.

PROMPT>  ec2-describe-snapshots snap-78a54011

Amazon EBS returns information about all snapshots that you own.

SNAPSHOT snap-78a54011 vol-4d826724 pending 2008-02-15T09:03:58+0000   60%

When the snapshot is complete, its status will change to completed and the percentage will change to 100%.

Detaching an Amazon EBS Volume from an Instance

An Amazon EBS volume can be detached from an instance by either explicitly detaching the volume or terminating the instance. This example unmounts the volume and explicitly detaches it from the instance.

	Caution
	A volume must be unmounted inside the instance before being detached. Failure to do so will result in damage to the file system or the data it contains.

To detach an Amazon EBS volume

Enter the following command.

PROMPT>  ec2-detach-volume vol-4d826724

Amazon EBS returns information similar to the following example.

ATTACHMENT vol-4d826724 i-6058a509 /dev/sdh detaching 2008-02-14T00:00:17+0000

To detach an Amazon EBS volume by terminating the instance

Enter the following command.

PROMPT>  ec2-terminate-instances i-6058a509

Amazon EBS returns information similar to the following example.

INSTANCE    i-6058a509    running shutting-down

To verify the volume is no longer attached to the instance, use the DescribeVolumes.

Deleting an Amazon EBS Snapshot

After a snapshot is no longer needed, it can be deleted. This example deletes a snapshot.

To delete a snapshot

Enter the following command.
```
PROMPT>  ec2-delete-snapshot snap-78a54011
```
Amazon EBS returns information similar to the following example.
```
SNAPSHOT snap-78a54011 
```

Deleting an Amazon EBS Volume

After a volume is no longer needed, it can be deleted. Once deleted, its data is deleted and it cannot be attached to any instance. However, you can store a snapshot of the volume that you can use to recreate it later.

This example deletes a volume.

To delete a volume

Enter the following command.
```
PROMPT>  ec2-delete-volume vol-4282672b
```
Amazon EBS returns information similar to the following example.
```
VOLUME vol-4282672b 
```