Reduce snapshot usage costs-Elastic Compute Service(ECS)-阿里云帮助中心

This topic describes how to reduce snapshot storage costs by managing snapshot retention, optimizing automatic snapshot policies, and archiving snapshots.

Important

Once a snapshot is deleted, you cannot recover its data. Before you delete a snapshot, ensure the operation does not affect your business or compliance requirements.

Manage snapshot retention

You are charged for snapshots based on their size and retention period. Retaining more snapshots for longer periods increases storage costs. Define a reasonable creation frequency and retention period based on your business requirements.

Use case	Creation frequency	Retention period	Description
Core applications	Every 1 to 2 days	Several months or longer	Depends on data criticality
Non-core applications	Every 1 to 2 weeks	Several days or weeks	Depends on data criticality
Software upgrades	On-demand	Delete promptly	This prevents unnecessary costs from long-term retention.
Critical file modifications
Application data migration
Test environments

If you no longer need a snapshot or if you exceed your snapshot quota, you can delete snapshots to free up space and reduce costs.

Optimize automatic snapshot policies

If you no longer need periodic data backups, disassociate the automatic snapshot policy from your disks. This prevents automatic snapshot creation and reduces storage costs.
By default, the lifecycle of an automatic snapshot is tied to its policy's retention period, and the snapshot persists after the disk is released. To change this, you can enable the feature that deletes automatic snapshots when the disk is released.

Important
If you enable the Delete Automatic Snapshots While Releasing Disk feature, all automatic snapshots of a disk are deleted when the disk is released, even if the snapshots have not expired. This applies when a disk is released manually, with an instance, or during a system disk replacement.
1. Go to ECS console - Block Storage. In the top navigation bar, select the target region and resource group.
2. Find the target disk and click Edit Attributes in the Actions column.
3. In the Modify Disk Property dialog box, select Delete Automatic Snapshots While Releasing Disk and then click OK.
  
  You can clear this check box later to disable the feature.
If you do not need cross-region disaster recovery or access for your snapshots, disable the cross-region replication policy. This reduces data transfer fees and storage costs for replicated snapshots in the destination region.

Archive snapshots

If you need to retain snapshots long-term but access them infrequently, archive the snapshots. Converting standard snapshots to archive snapshots reduces storage costs.

Archiving only some of the snapshots for a disk may not reduce costs. For details about how snapshot size is calculated, see How snapshot size is calculated.

The following example shows a cost comparison before and after archiving all standard snapshots (Snapshot A, Snapshot B, and Snapshot C) of a disk in the China (Hangzhou) region for two months. The calculation uses the following unit prices for the China (Hangzhou) region:

Standard snapshot: CNY 0.12/GB/month
Archive snapshot: CNY 0.06/GB/month

The prices in this example are for reference only. For the actual prices, see the ECS Pricing page.

The following table compares the costs before and after archiving.

Item	Standard snapshot size	Archive snapshot size	Standard snapshot cost	Archive snapshot cost	Total snapshot cost
Before archiving	50 GB	N/A	CNY 0.12/GB/month × 50 GB × 2 months = CNY 12.00	N/A	CNY 12.00
After archiving	N/A	50 GB	N/A	CNY 0.06/GB/month × 50 GB × 2 months = CNY 6.00	CNY 6.00

The total cost is lower after archiving. This shows that archiving all of a disk's snapshots can reduce your storage costs.

References

To view the size of snapshots for a disk, see View snapshot size.
For more information about snapshot billing, see Snapshot billing. To understand your snapshot costs for each region, view your bills in the Billing Management console. For instructions, see View snapshot bills.