Amazon EC2 instance root device volume - Amazon Elastic Compute Cloud

Amazon EC2 instance root device volume

When you launch an instance, the root device volume contains the image used to boot the instance. When you launch a Windows instance, a root EBS volume is created from an EBS snapshot and attached to the instance.

Configure the root volume to persist

By default, the root volume is deleted when the instance terminates (the DeleteOnTermination attribute is true). Using the console, you can change DeleteOnTermination when you launch an instance. To change this attribute for an existing instance, you must use the command line.

Configure the root volume to persist during instance launch

You can configure the root volume to persist when you launch an instance using the Amazon EC2 console or the command line tools.

Console

To configure the root volume to persist when you launch an instance using the console

  1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

  2. In the navigation pane, choose Instances and then choose Launch instances.

  3. On the Choose an Amazon Machine Image (AMI) page, select the AMI to use and choose Select.

  4. Follow the wizard to complete the Choose an Instance Type and Configure Instance Details pages.

  5. On the Add Storage page, deselect Delete On Termination for the root volume.

  6. Complete the remaining wizard pages, and then choose Launch.

AWS CLI

To configure the root volume to persist when you launch an instance using the AWS CLI

Use the run-instances command and include a block device mapping that sets the DeleteOnTermination attribute to false.

C:\> aws ec2 run-instances --block-device-mappings file://mapping.json ...other parameters...

Specify the following in mapping.json.

[ { "DeviceName": "/dev/sda1", "Ebs": { "DeleteOnTermination": false } } ]
Tools for Windows PowerShell

To configure the root volume to persist when you launch an instance using the Tools for Windows PowerShell

Use the New-EC2Instance command and include a block device mapping that sets the DeleteOnTermination attribute to false.

C:\> $ebs = New-Object Amazon.EC2.Model.EbsBlockDevice C:\> $ebs.DeleteOnTermination = $false C:\> $bdm = New-Object Amazon.EC2.Model.BlockDeviceMapping C:\> $bdm.DeviceName = "dev/xvda" C:\> $bdm.Ebs = $ebs C:\> New-EC2Instance -ImageId ami-0abcdef1234567890 -BlockDeviceMapping $bdm ...other parameters...

Configure the root volume to persist for an existing instance

You can configure the root volume to persist for a running instance using the command line tools only.

AWS CLI

To configure the root volume to persist for an existing instance using the AWS CLI

Use the modify-instance-attribute command with a block device mapping that sets the DeleteOnTermination attribute to false.

aws ec2 modify-instance-attribute --instance-id i-1234567890abcdef0 --block-device-mappings file://mapping.json

Specify the following in mapping.json.

[ { "DeviceName": "/dev/xvda", "Ebs": { "DeleteOnTermination": false } } ]
Tools for Windows PowerShell

To configure the root volume to persist for an existing instance using the AWS Tools for Windows PowerShell

Use the Edit-EC2InstanceAttribute command with a block device mapping that sets the DeleteOnTermination attribute to false.

C:\> $ebs = New-Object Amazon.EC2.Model.EbsInstanceBlockDeviceSpecification C:\> $ebs.DeleteOnTermination = $false C:\> $bdm = New-Object Amazon.EC2.Model.InstanceBlockDeviceMappingSpecification C:\> $bdm.DeviceName = "/dev/xvda" C:\> $bdm.Ebs = $ebs C:\> Edit-EC2InstanceAttribute -InstanceId i-1234567890abcdef0 -BlockDeviceMapping $bdm

Confirm that a root volume is configured to persist

You can confirm that a root volume is configured to persist using the Amazon EC2 console or the command line tools.

New console

To confirm that a root volume is configured to persist using the Amazon EC2 console

  1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

  2. In the navigation pane, choose Instances and then select the instance.

  3. In the Storage tab, under Block devices, locate the entry for the root volume. If Delete on termination is No, the volume is configured to persist.

Old console

To confirm that a root volume is configured to persist using the Amazon EC2 console

  1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

  2. In the navigation pane, choose Instances and then select the instance.

  3. In the Description tab, choose the entry for Root device. If Delete on termination is False, the volume is configured to persist.

AWS CLI

To confirm that a root volume is configured to persist using the AWS CLI

Use the describe-instances command and verify that the DeleteOnTermination attribute in the BlockDeviceMappings response element is set to false.

C:\> aws ec2 describe-instances --instance-id i-1234567890abcdef0
... "BlockDeviceMappings": [ { "DeviceName": "/dev/sda1", "Ebs": { "Status": "attached", "DeleteOnTermination": false, "VolumeId": "vol-1234567890abcdef0", "AttachTime": "2013-07-19T02:42:39.000Z" } } ...
Tools for Windows PowerShell

To confirm that a root volume is configured to persist using the AWS Tools for Windows PowerShell

Use the Get-EC2Instance and verify that the DeleteOnTermination attribute in the BlockDeviceMappings response element is set to false.

C:\> (Get-EC2Instance -InstanceId i-i-1234567890abcdef0).Instances.BlockDeviceMappings.Ebs

Change the initial size of the root volume

By default, the size of the root volume is determined by the size of the snapshot. You can increase the initial size of the root volume using the block device mapping of the instance as follows.

  1. Determine the device name of the root volume specified in the AMI, as described in View the EBS volumes in an AMI block device mapping.

  2. Confirm the size of the snapshot specified in the AMI block device mapping, as described in View Amazon EBS snapshot information.

  3. Override the size of the root volume using the instance block device mapping, as described in Update the block device mapping when launching an instance, specifying a volume size that is larger than the snapshot size.

For example, the following entry for the instance block device mapping increases the size of the root volume, /dev/xvda, to 100 GiB. You can omit the snapshot ID in the instance block device mapping because the snapshot ID is already specified in the AMI block device mapping.

{ "DeviceName": "/dev/xvda", "Ebs": { "VolumeSize": 100 } }

For more information, see Block device mappings.