Copy an Amazon EBS snapshot - Amazon Elastic Compute Cloud

Copy an Amazon EBS snapshot

With Amazon EBS, you can create point-in-time snapshots of volumes, which we store for you in Amazon S3. After you create a snapshot and it has finished copying to Amazon S3 (when the snapshot status is completed), you can copy it from one AWS Region to another, or within the same Region. Amazon S3 server-side encryption (256-bit AES) protects a snapshot's data in transit during a copy operation. The snapshot copy receives an ID that is different from the ID of the original snapshot.

To copy multi-volume snapshots to another AWS Region, retrieve the snapshots using the tag you applied to the multi-volume snapshot set when you created it. Then individually copy the snapshots to another Region.

If you would like another account to be able to copy your snapshot, you must either modify the snapshot permissions to allow access to that account or make the snapshot public so that all AWS accounts can copy it. For more information, see Share an Amazon EBS snapshot.

For information about copying an Amazon RDS snapshot, see Copying a DB Snapshot in the Amazon RDS User Guide.

Use cases
  • Geographic expansion: Launch your applications in a new AWS Region.

  • Migration: Move an application to a new Region, to enable better availability and to minimize cost.

  • Disaster recovery: Back up your data and logs across different geographical locations at regular intervals. In case of disaster, you can restore your applications using point-in-time backups stored in the secondary Region. This minimizes data loss and recovery time.

  • Encryption: Encrypt a previously unencrypted snapshot, change the key with which the snapshot is encrypted, or create a copy that you own in order to create a volume from it (for encrypted snapshots that have been shared with you).

  • Data retention and auditing requirements: Copy your encrypted EBS snapshots from one AWS account to another to preserve data logs or other files for auditing or data retention. Using a different account helps prevent accidental snapshot deletions, and protects you if your main AWS account is compromised.

Prerequisites

  • You can copy any accessible snapshots that have a completed status, including shared snapshots and snapshots that you have created.

  • You can copy AWS Marketplace, VM Import/Export, and Storage Gateway snapshots, but you must verify that the snapshot is supported in the destination Region.

  • To copy an encrypted snapshot, your user must have the following permissions to use Amazon EBS encryption.

    • kms:DescribeKey

    • kms:CreateGrant

    • kms:GenerateDataKey

    • kms:GenerateDataKeyWithoutPlaintext

    • kms:ReEncrypt

    • kms:Decrypt

  • To copy an encrypted snapshot shared from another AWS account, you must have permissions to use customer managed key that was used to encrypt the snapshot. For more information, see Share a KMS key.

Considerations

  • There is a limit of 20 concurrent snapshot copy requests per destination Region. If you exceed this quota, you receive a ResourceLimitExceeded error. If you receive this error, wait for one or more of the copy requests to complete before making a new snapshot copy request.

  • User-defined tags are not copied from the source snapshot to the new snapshot. You can add user-defined tags during or after the copy operation. For more information, see Tag your Amazon EC2 resources.

  • Snapshots created by a snapshot copy operation have an arbitrary volume ID, such as vol-ffff or vol-ffffffff. These arbitrary volume IDs should not be used for any purpose.

  • Resource-level permissions specified for the snapshot copy operation apply only to the new snapshot. You cannot specify resource-level permissions for the source snapshot. For an example, see Example: Copying snapshots.

Pricing

  • For pricing information about copying snapshots across AWS Regions and accounts, see Amazon EBS Pricing.

  • If you copy a snapshot and encrypt it to a new KMS key, a complete (non-incremental) copy is created. This results in additional storage costs.

  • If you copy a snapshot to a new Region, a complete (non-incremental) copy is created. This results in additional storage costs. Subsequent copies of the same snapshot are incremental.

  • The first snapshot copy from a snapshot in the same account and the same Region using the same customer managed key will be a complete (non-incremental) copy. This results in additional storage costs. Subsequent copies of the same snapshot are incremental.

  • If you use external or cross-region data transfers, additional EC2 data transfer charges will apply. And if you delete any snapshots after initiation, you are still charged for the data that has already been transferred.

Incremental snapshot copying

Whether a snapshot copy is incremental is determined by the most recently completed snapshot copy. When you copy a snapshot across Regions or accounts, the copy is an incremental copy if the following conditions are met:

  • The snapshot was copied to the destination Region or account previously.

  • The most recent snapshot copy still exists in the destination Region or account.

  • All copies of the snapshot in the destination Region or account are either unencrypted or were encrypted using the same KMS key.

If the most recent snapshot copy was deleted, the next copy is a full copy, not an incremental copy. If a copy is still pending when you start another copy, the second copy starts only after the first copy finishes.

Snapshot copy operations within a single account and the same Region using a customer managed key will generate a complete (non-incremental) copy. Subsequent copies of the same snapshot are incremental.

Incremental snapshot copying reduces the time required to copy snapshots and saves on data transfer and storage costs by not duplicating data.

We recommend that you tag your snapshots with the volume ID and creation time so that you can keep track of the most recent snapshot copy of a volume in the destination Region or account.

To see whether your snapshot copies are incremental, check the copySnapshot CloudWatch event.

Encryption and snapshot copying

When you copy a snapshot, you can encrypt the copy or you can specify a KMS key that is different than the original, and the resulting copied snapshot uses the new KMS key. However, changing the encryption status of a snapshot during a copy operation could result in a full (not incremental) copy, which might incur greater data transfer and storage charges. For more information, see Incremental snapshot copying.

To copy an encrypted snapshot shared from another AWS account, you must have permissions to use the snapshot and the customer managed key (CMK) that was used to encrypt the snapshot. When using an encrypted snapshot that was shared with you, we recommend that you re-encrypt the snapshot by copying it using a KMS key that you own. This protects you if the original KMS key is compromised, or if the owner revokes it, which could cause you to lose access to any encrypted volumes that you created using the snapshot. For more information, see Share an Amazon EBS snapshot.

You apply encryption to EBS snapshot copies by setting the Encrypted parameter to true. (The Encrypted parameter is optional if encryption by default is enabled).

Optionally, you can use KmsKeyId to specify a custom key to use to encrypt the snapshot copy. (The Encrypted parameter must also be set to true, even if encryption by default is enabled.) If KmsKeyId is not specified, the key that is used for encryption depends on the encryption state of the source snapshot and its ownership.

The following table describes the encryption outcomes for each possible combination of settings when copying snapshots that you own and snapshots that are shared with you.

Topics
    Encryption by default Is Encrypted parameter set? Source snapshot encryption status Default (no KMS key specified) Custom (KMS key specified)
    Disabled No Unencrypted Unencrypted N/A
    Encrypted Encrypted by AWS managed key
    Yes Unencrypted Encrypted by default KMS key Encrypted by specified KMS key**
    Encrypted Encrypted by default KMS key
    Enabled No Unencrypted Encrypted by default KMS key N/A
    Encrypted Encrypted by default KMS key
    Yes Unencrypted Encrypted by default KMS key Encrypted by specified KMS key**
    Encrypted Encrypted by default KMS key

    ** This is the KMS key specified in the copy snapshot action. This KMS key is used instead of the default KMS key for the account and Region.

    Copy a snapshot

    To copy a snapshot, use one of the following methods.

    Console
    To copy a snapshot using the console
    1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

    2. In the navigation pane, choose Snapshots.

    3. Select the snapshot to copy, and then choose Actions, Copy snapshot.

    4. For Description, enter a brief description for the snapshot copy.

      By default, the description includes information about the source snapshot so that you can identify a copy from the original. You can change this description as needed.

    5. For Destination Region, select the Region in which to create the snapshot copy.

    6. Specify the encryption status for the snapshot copy.

      If the source snapshot is encrypted, or if your account is enabled for encryption by default, then the snapshot copy is automatically encrypted and you can't change its encryption status.

      If the source snapshot is unencrypted and your account is not enabled for encryption by default, encryption is optional. To encrypt the snapshot copy, for Encryption, select Encrypt this snapshot. Then, for KMS key, select the KMS key to use to encrypt the snapshot in the destination Region.

    7. Choose Copy snapshot.

    AWS CLI
    To copy a snapshot using the AWS CLI

    Use the copy-snapshot command.

    Tools for Windows PowerShell
    To copy a snapshot using the Tools for Windows PowerShell

    Use the Copy-EC2Snapshot command.

    To check for failure

    If you attempt to copy an encrypted snapshot without having permissions to use the encryption key, the operation fails silently. The error state is not displayed in the console until you refresh the page. You can also check the state of the snapshot from the command line, as in the following example.

    aws ec2 describe-snapshots --snapshot-id snap-0123abcd

    If the copy failed because of insufficient key permissions, you see the following message: "StateMessage": "Given key ID is not accessible".

    When copying an encrypted snapshot, you must have DescribeKey permissions on the default CMK. Explicitly denying these permissions results in copy failure. For information about managing CMK keys, see Authentication and access control for AWS KMS.