This topic describes how to view the free quota for backup usage of an ApsaraDB RDS for SQL Server instance. It also provides more information about how to calculate your excess backup storage usage. The free quota can vary based on the instance configuration.

Background information

Backup files occupy backup storage. Each RDS instance is allocated with a free quota for backup storage. If the total size of backup files exceeds the free quota, additional fees are incurred.


Free quota = 50% × Storage capacity purchased during instance creation (unit: GB; rounded up to the next integer)

Excess backup storage usage = Size of data backup files + Size of log backup files - Free quota

If the size of data backup files is 30 GB, the size of log backup files is 10 GB, and the storage capacity purchased during instance creation is 60 GB., then the excess backup storage usage for which you must pay an hourly rate is 10 GB based on the following calculation: Excess backup storage usage = 30 + 10 - 50% × 60 = 10 (GB). This indicates that you must pay for an additional 10 GB of backup storage per hour.

  • For more information about the hourly rate of excess backup storage usage, see the pricing information at ApsaraDB for RDS.
  • The RDS Basic Edition that is used with some database engines supports a free-of-charge retention period of seven days. For more information, see the ApsaraDB for RDS console.Backup storage usage on RDS Basic Edition


  1. Log on to the ApsaraDB for RDS console.
  2. In the left-side navigation pane, click Instances. In the top navigation bar, select the region where the target RDS instance resides.
    Select a region
  3. Find the target instance and click the instance ID.
  4. In the Usage Statistics section at the lower part of the page, view the free quota for backup storage to the right of Backup Size.
    Note The free quota for backup storage can vary based on the instance configuration. The following figure only shows an example.


  • Will backup files occupy the storage that I purchased during instance creation?

    No, backup files do not occupy the storage that you purchased during instance creation.

  • Can I purchase subscription-billed backup storage?

    No, you cannot purchase backup storage.