Keep snapshot storage costs under control by optimizing snapshot retention, optimizing automatic policies, archiving snapshots for long-term retention and purchasing Storage Capacity Units (SCU).
Deleting a snapshot is irreversible—you cannot recover the data. Before deleting, verify the snapshot is no longer needed for business operations or compliance.
How snapshot billing works
Snapshot storage is billed hourly based on:
Snapshot type — Standard or Archive
Snapshot size — Total storage consumed (incremental after initial snapshot)
Retention period — How long snapshots are kept
Region — Prices vary by region
View your current snapshot costs in the ECS console: Storage & Snapshots > Snapshots > Snapshot Size tab.
Optimize snapshot retention
Snapshot billing is a function of data volume and retention time. To mitigate costs, implement a snapshot policy that defines the creation frequency and retention period based on your operational requirements.
Use case | Creation frequency | Retention period |
Core applications | Every 1-2 days | Several months or longer |
Non-core applications | Every 1-2 weeks | Several days to weeks |
Software upgrades | On-demand | Delete promptly |
Critical file modifications | ||
Application data migration | ||
Test environments |
How to delete
See Delete snapshots for instructions.
Optimize automatic policies
Automatic snapshot policies create snapshots on schedule. Poorly configured policies can generate unnecessary costs.
Review current policies
In the ECS console, go to Storage & Snapshots > Snapshots.
Click the Automatic Snapshot Policies tab.
Review each policy's Policy Details:
Execution Frequency — How often snapshots are created
Retention Period — How long snapshots are kept
Modify retention period
On the Automatic Snapshot Policies tab, click Modify Policy for the target policy.
Adjust Retention Period to match actual needs.
Click OK.
Disassociate policies from unused disks
If a disk no longer needs automatic snapshots:
Click Modify Policy for the automatic snapshot policy.
Remove the disk from the associated disks list.
Enable automatic deletion with disk release
By default, automatic snapshots persist after disk release. Enable automatic deletion to avoid orphan snapshots:
Go to Storage & Snapshots > Block Storage.
Click Edit Attributes for the target disk.
Select Delete Automatic Snapshots While Releasing Disk.
Click Confirm.
When enabled, releasing a disk (manually, with an instance, or during system disk replacement) deletes all its automatic snapshots—even unexpired ones.
Disable cross-region replication
Cross-region snapshot replication incurs transfer fees and storage fees in the destination region.
Review automatic snapshot policies for cross-region replication settings.
Disable replication for policies where cross-region disaster recovery isn't required.
Archive snapshots for long-term retention
For snapshots required for long-term retention but rarely accessed, archive them to reduce storage costs.
When to archive
Archive snapshots that meet ALL criteria:
Required for retention longer than 90 days
Rarely or never accessed
Not needed for instant restore
Cost comparison
For a 50 GB disk with three snapshots in China (Hangzhou), kept for two months:
Snapshot type | Storage rate | Two-month total |
Standard | USD 0.0173/GB | USD 1.73 |
Archive | USD 0.0085/GB | USD 0.85 |
Savings: ~50% by archiving.
Archiving individual snapshots may not reduce costs due to how incremental snapshot size is calculated. Archive all snapshots of a disk together for maximum savings. See How snapshot size is calculated.
How to archive
See Archive snapshots for instructions.
Purchase SCU
SCU provide discounted capacity that offsets snapshot storage costs.
Benefits
Cost savings of 20–30% compared to pay-as-you-go pricing
Flexible capacity across multiple storage types
No commitment to specific resources
Limitations
SCU cannot offset Archive snapshot costs
SCU applies only within the purchased region
How to purchase
In the Snapshot Size tab, locate the Storage Capacity Units section.
Click Buy Now.
Select capacity and billing term based on projected usage.
Calculate monthly snapshot storage from the Snapshot Size chart before purchasing SCU.
Verify cost reduction
After implementing optimizations:
Go to Storage & Snapshots > Snapshots > Snapshot Size tab.
Compare the storage trend before and after changes.
Wait at least 24 hours for billing to reflect changes.
Check billing details in the Alibaba Cloud Management Console under Billing > Bills.
FAQ
How do I find which snapshots use the most storage?
In the ECS console, go to Storage & Snapshots > Snapshots. On the Disk Snapshots tab, sort by creation time or filter by disk to identify large or old snapshots. The Snapshot Size tab shows total storage by snapshot type.
Why didn't archiving reduce my costs?
Incremental snapshots share data blocks. Archiving only some snapshots of a disk may not reduce the total size because the archived snapshot still references blocks used by non-archived snapshots. Archive all snapshots of a disk together for maximum savings.
Can I recover a deleted snapshot?
No. Snapshot deletion is permanent. Always verify you no longer need a snapshot before deleting it.
What happens to automatic snapshots when I release a disk?
By default, automatic snapshots are retained after disk release and continue incurring costs. Enable Delete Automatic Snapshots While Releasing Disk in disk attributes to automatically clean up.