How Amazon Data Lifecycle Manager works

The following are the key elements of Amazon Data Lifecycle Manager.

Policies

With Amazon Data Lifecycle Manager, you create policies to define your backup creation and retention requirements. These policies typically specify the following:

Amazon Data Lifecycle Manager offers default policies and custom policies.

Default policies

Default policies back up all volumes and instances in a Region that do not have recent backups. You can optionally exclude volumes and instances by specifying exclusion parameters.

You can have only one default policy per resource type in each account and AWS Region.

Custom policies

Custom policies target specific resources based on their assigned tags and support advanced features, such as fast snapshot restore, snapshot archiving, cross-account copying, and pre and post scripts. A custom policy can include up to 4 schedules, where each schedule can have its own creation frequency, retention threshold, and advanced feature configuration.

For more information, see Amazon Data Lifecycle Manager default policies vs custom policies.

Policy schedules (custom policies only)

Policy schedules define when snapshots or AMIs are created by the policy. Policies can have up to four schedules—one mandatory schedule, and up to three optional schedules.

Adding multiple schedules to a single policy lets you create snapshots or AMIs at different frequencies using the same policy. For example, you can create a single policy that creates daily, weekly, monthly, and yearly snapshots. This eliminates the need to manage multiple policies.

For each schedule, you can define the frequency, fast snapshot restore settings (snapshot lifecycle policies only), cross-Region copy rules, and tags. The tags that are assigned to a schedule are automatically assigned to the snapshots or AMIs that are created when the schedule is initiated. In addition, Amazon Data Lifecycle Manager automatically assigns a system-generated tag based on the schedule's frequency to each snapshot or AMI.

Each schedule is initiated individually based on its frequency. If multiple schedules are initiated at the same time, Amazon Data Lifecycle Manager creates only one snapshot or AMI and applies the retention settings of the schedule that has the highest retention period. The tags of all of the initiated schedules are applied to the snapshot or AMI.

Target resource tags (custom policies only)

Amazon Data Lifecycle Manager custom policies use resource tags to identify the resources to back up. When you create a snapshot or EBS-backed AMI policy, you can specify multiple target resource tags. All resources of the specified type (instance or volume) that have at least one of the specified target resource tags will be targeted by the policy. For example, if you create a snapshot policy that targets volumes and you specify purpose=prod, costcenter=prod, and environment=live as target resource tags, then the policy will target all volumes that have any of those tag-key value pairs.

If you want to run multiple policies on a resource, you can assign multiple tags to the target resource, and then create separate policies that each target a specific resource tag.

You can't use the \ or = characters in a tag key. Target resource tags are case sensitive. For more information, see Tag your resources.

Snapshots

Snapshots are the primary means to back up data from your EBS volumes. To save storage costs, successive snapshots are incremental, containing only the volume data that changed since the previous snapshot. When you delete one snapshot in a series of snapshots for a volume, only the data that's unique to that snapshot is removed. The rest of the captured history of the volume is preserved. For more information, see Amazon EBS snapshots.

EBS-backed AMIs

An Amazon Machine Image (AMI) provides the information that's required to launch an instance. You can launch multiple instances from a single AMI when you need multiple instances with the same configuration. Amazon Data Lifecycle Manager supports EBS-backed AMIs only. EBS-backed AMIs include a snapshot for each EBS volume that's attached to the source instance. For more information, see Amazon Machine Images (AMI).

Amazon Data Lifecycle Manager tags

Amazon Data Lifecycle Manager applies the following system tags to all snapshots and AMIs created by a policy, to distinguish them from snapshots and AMIs created by any other means:

You can also specify custom tags to be applied to snapshots and AMIs on creation. You can't use the \ or = characters in a tag key.

The target tags that Amazon Data Lifecycle Manager uses to associate volumes with a snapshot policy can optionally be applied to snapshots created by the policy. Similarly, the target tags that are used to associate instances with an AMI policy can optionally be applied to AMIs created by the policy.