# Time-based copies for Amazon EBS snapshots and EBS-backed AMIs
Time-based copies can help you meet compliance or business requirements for data replication by ensuring that your EBS snapshots and EBS-backed AMIs are copied, within and across AWS Regions, in a specified timeframe. Time-based copies can also help backup administrators meet stringent disaster recovery requirements (Recovery Point Objectives and Recovery Time Objectives), and it improves development agility by ensuring predictable copying times for snapshots and EBS-backed AMIs.
With time-based snapshot and EBS-backed AMI copy operations, you specify a completion duration, between 15 minutes and 48 hours, in which the copy is to be completed. The completion duration must be specified in 15 minute increments.
**Topics**
+ [Quotas](#time-based-copies-quota)
+ [Determine your completion duration](#time-based-copies-how)
+ [Considerations](#time-based-copies-considerations)
+ [Monitoring](#time-based-copies-monitoring)
+ [Pricing and billing](#time-based-copies-pricing)
## Quotas
The following quotas apply to time-based snapshot and EBS-backed AMI copy operations:
| Quota | Description | Quota value | Adjustable |
| --- | --- | --- | --- |
| Snapshot copy operation throughput quota | The maximum throughput that can be achieved by a single time-based snapshot copy operation. For AMI copy operations, the quota applies to each individual snapshot associated with the AMI. | 500 MiB/s | No |
| Cumulative snapshot copy throughput quota | The maximum cumulative throughput that can be achieved by concurrent time-based snapshot copy operations between a source and destination Region. For AMI copy operations, each individual snapshot associated with the AMI counts towards the quota. | 2,000 MiB/s | [Yes](https://console.aws.amazon.com/servicequotas/home/services/ebs/quotas/L-E137849C) |
When you initiate a **time-based snapshot copy operation**, you specify a completion duration. The throughput used by the request is determined by the size of the snapshot data and the requested completion duration. For example, if you copy a snapshot that has 225,000 MiB (0.214 TiB) of data, and you request a completion duration of 15 minutes, the throughput is 250 MiB/s (225,000 MiB ÷ 15 minutes = 250 MiB/s).
When you initiate a **time-based AMI copy operation**, the completion duration you specify applies to each snapshot associated with the AMI. Because each snapshot can have a different size, each snapshot is copied at a different throughput to ensure that all snapshots are copied within the completion duration. For example, say you have an AMI with the following associated snapshots:
+ Snapshot 1: 200,000 MiB
+ Snapshot 2: 500,000 MiB
+ Snapshot 3: 450,000 MiB
If you initiate a time-based copy for this AMI and specify a completion duration of 60 minutes, the request uses the following throughput:
+ Snapshot 1: 55.56 MiB/s (200,000 MiB ÷ 60 minutes = 55.56 MiB/s)
+ Snapshot 2: 138.89 MiB/s (500,000 MiB ÷ 60 minutes = 138.89 MiB/s)
+ Snapshot 3: 125 MiB/s (450,000 MiB ÷ 60 minutes = 125 MiB/s)
This means that the request uses 319.45 MiB/s of your cumulative snapshot copy throughput quota to ensure that the copy completes in 60 minutes.
If you initiate a time-based snapshot or EBS-backed AMI copy request and your available cumulative snapshot copy throughput quota is:
+ greater than or equal to the required throughput rate, the copy completes within the requested completion duration.
+ less than the required throughput rate but greater than zero, the request succeeds but it will take longer than you requested. The copy is completed using your available throughput quota.
+ zero (quota reached), the request fails.
## Determine your completion duration
The minimum completion duration you can request for a time-based snapshot or EBS-backed AMI copy operation is 15 minutes, and the maximum completion duration you can request is 48 hours. The completion duration must be specified in 15 minute increments.
**Concurrent time-based snapshot copy operations**
You can perform concurrent time-based snapshot copy operations between the same source and destination Regions, as long as the combined throughput of all of the concurrent operations is within your cumulative snapshot copy throughput quota (2,000 MiB/s by default).
To determine whether you can achieve your required completion duration for your existing snapshots, divide the combined size of all of your snapshots by your required completion duration to determine the required throughput rate.
**Tip**
If you don't know the exact size of the data in your snapshots, you can use the full snapshot size as a proxy instead. To get the full snapshot size, use the [ describe-snapshots](https://docs.aws.amazon.com/cli/latest/reference/ec2/describe-snapshots.html) AWS CLI command.
```
required throughput rate = combined snapshot size ÷ required completion duration
```
If the required throughput rate is less than your cumulative snapshot copy throughput quota, you can achieve your required completion duration. If the required throughput rate is greater than your cumulative snapshot copy throughput quota, we recommend that you request a quota increase that is at least 10% higher than your required throughput rate.
**Tip**
The Amazon EC2 console provides a calculator that you can use to check how much snapshot data you copied between two Regions over a specific period, and the minimum achievable completion duration that you can achieve for that amount of data, based on a specific cumulative snapshot copy throughput quota. The calculator uses the `SnapshotCopyBytesTransferred` CloudWatch metric to calculate data copied between two Regions over a period. To open the calculator, in the Amazon EC2 console navigation panel, select **Snapshots**, and then choose **Actions**, **Launch copy duration calculator**.
The snapshot copy duration calculator are not supported with AWS Outposts, Local Zones, and Wavelength Zones.
**Individual time-based snapshot copy operations**
You can calculate the minimum completion duration for an individual time-based snapshot copy operation by dividing the size of the snapshot data by the snapshot copy operation throughput quota (500 MiB/s).
**Tip**
If you don't know the exact size of the data in your snapshots, you can use the full snapshot size as a proxy instead. To get the full snapshot size, use the [ describe-snapshots](https://docs.aws.amazon.com/cli/latest/reference/ec2/describe-snapshots.html) AWS CLI command.
```
minimum completion duration = Max(15 minutes, (snapshot data size ÷ 500 MiB/s)
```
For example, the minimum completion duration for a snapshot with 900,000 MiB of data is 30 minutes.
```
minimum completion duration = Max(15 minutes, (900,000 MiB ÷ 500 MiB/s)
= Max(15 minutes, 30 minutes)
= 30 minutes
```
**Time-based AMI copy operations**
When you initiate a time-based AMI copy operation for an EBS-backed AMI with a single associated snapshot, it behaves in the same way as an **individual time-based snapshot copy operation**, and the same throughput limitations apply.
When you initiate a time-based AMI copy operation for an EBS-backed AMI with a multiple associated snapshots, it behaves in the same way as **concurrent time-based snapshot copy operations** and the same throughput limitations apply. Each associated snapshot results in a separate snapshot copy request, each of which contributes to your cumulative snapshot copy throughput quota. The completion duration that you specify applies to each associated snapshot.
## Considerations
+ You can initiate time-based snapshot and EBS-backed AMI copy operations when copying snapshots within the same Region or when copying snapshots across Regions.
+ If you initiate two time-based copy operations for the same snapshot or AMI, the second copy operation's completion duration starts only after the first copy operation completes.
+ Time-based copy operations and the snapshot copy duration calculator are not supported with AWS Outposts, Local Zones, and Wavelength Zones.
## Monitoring
You can monitor the progress of time-based snapshot and EBS-backed AMI copy operations using the Amazon EC2 console and the AWS CLI. In the console, select the snapshot and then, in the **Details tab**, inspect the ** Progress** field. With the AWS CLI, inspect the `Progress` output element in the [ describe-snapshots](https://docs.aws.amazon.com/cli/latest/reference/ec2/describe-snapshots.html) command response.
You can check whether a time-based snapshot or EBS-backed AMI copy operation completed within the requested completion duration by checking the difference between the **Started** and **Completed** times in the console, or `StartTime` and `CompletionTime` in the `describe-snapshots` response.
You can also use the `copySnapshot` Amazon EventBridge event to monitor the outcome of time-based copy operations. The event indicates whether the operation completed and whether the requested completion duration was met. If the completion duration was not met, the event includes more information about the cause. For more information, see [EBS snapshot events](ebs-cloud-watch-events.md#snapshot-events).
## Pricing and billing
**Note**
Similar to standard snapshot copy operations, if you copy a snapshot to a new Region, a full (non-incremental) copy is created, which results in additional storage costs. Subsequent copies of the same snapshot are incremental. Additionally, if you use external or cross-region data transfers, additional Amazon EC2 data transfer charges will apply.
Additional charges apply for time-based snapshot and EBS-backed AMI copy operations. Time-based copy operations are charged at a rate that is based on the requested completion duration, per GiB of snapshot data copied. The fixed rates are as follows:
**Note**
The completion duration must be specified in 15 minute increments. The minimum completion duration is 15 minutes, and the maximum is 48 hours.
+ 15 minutes — \$10.020 per GiB of data
+ 30 minutes and 45 minutes — \$10.018 per GiB of data
+ 1 hour to 1 hour 45 minutes — \$10.016 per GiB of data
+ 2 hours to 3 hours 45 minutes — \$10.014 per GiB of data
+ 4 hours to 7 hours 45 minutes — \$10.012 per GiB of data
+ 8 hours to 15 hours 45 minutes — \$10.010 per GiB of data
+ 16 hours or more — \$10.005 per GiB of data
For example, if you copy a snapshot with 3,000 GiB of data with a completion duration of 8 hours, you are billed \$130 (\$10.010 x 3,000 GiB).
If you initiate a time-based copy operation, but the requested completion duration is not met due to you exceeding a quota, you are billed based on the actual completion duration instead of the requested completion duration. For example, if you request a completion duration of 1 hour, but the operation completes in 2 hours, you are billed based on the rate for the 2 hour completion duration.
If Amazon EBS is not able to achieve the requested completion duration or if a request is canceled due to service-side issues, you are not billed the additional charges for the time-based snapshot copy operation.
If you delete the snapshot copy while the time-based snapshot copy operation is still in progress, you are billed for the data copied up to that point at the rate corresponding to the specified completion duration.