Each ApsaraDB RDS for PostgreSQL instance includes a free backup storage quota. If your backup usage exceeds this quota, you are charged only for the excess — not the total usage. The quota amount depends on your disk type and purchased storage capacity.
How the free quota is calculated
| Disk type | Backup type | Free quota |
|---|---|---|
| Cloud disk | Snapshot backup | 200% x purchased storage capacity (GB, rounded up) |
| Premium Local SSD | Physical backup | 50% x purchased storage capacity (GB, rounded up) |
Excess backup storage is billed at an hourly rate. To calculate the billable amount:
Excess backup storage = size of data backup files + size of log backup files - free quotaExample: Your instance uses Premium Local SSDs with 60 GB of purchased storage. If your data backup files are 30 GB and log backup files are 10 GB, the excess is:
Excess backup storage = 30 + 10 - 50% × 60 = 10 (GB)Your bill reflects only the 10 GB of excess storage, not the total 40 GB of backup used.
For hourly rates, see Backup storage fees. If you use RDS Basic Edition, some database engines support a seven-day free retention period — check the ApsaraDB RDS console for details.
View the free quota in the console
Go to the Instances page. In the top navigation bar, select the region where your RDS instance resides. Find the instance and click its ID.
In the Usage Statistics section, check the value displayed to the right of Backup Usage. This is your current free quota.
The free quota varies based on your instance configuration.
FAQ
Does backup storage use the storage I purchased for my instance?
No. Backup storage is separate from the storage capacity you purchased when you created the instance. The two are completely isolated.
Can I purchase backup storage using subscription billing?
No. Backup storage cannot be purchased separately.