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    ApsaraDB RDS:Backup fees

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    ApsaraDB RDS:Backup fees

    Last Updated:Aug 28, 2026

    Backup storage for an ApsaraDB RDS for SQL Server instance is billed on a pay-as-you-go basis. Each instance has a free backup quota that is determined by its storage space and backup mode, and only the portion of the total backup size that exceeds this quota is billed.

    Billable items

    The following table lists the billable items of backup storage for an ApsaraDB RDS for SQL Server instance.

    Billable item

    Billable item code

    Associated product

    References

    RDS basic backup fees

    BackupCharged

    RDS

    Back up SQL Server data and Enable snapshot backup

    Cross-region backup storage fees

    DdrOssStorageSize

    RDS

    Cross-region backup

    Cross-region backup network traffic fees

    NetworkOutDuplicationSize

    Database Backup (DBS)

    —

    Internet traffic fees for backup downloads

    NetworkOutSize

    Database Backup (DBS)

    Backup downloads

    Billing rules

    Only the portion of the total backup size that exceeds the free quota is billed, and it is billed on a pay-as-you-go basis. The billing formula is the same for every backup mode:

    Hourly backup fee = (Total backup size − Free quota) × Unit price

    Backup fees depend on the total backup size, not on instance storage space usage. To check the total backup size, go to Basic Information > Instance Resources > Backup Usage on the instance details page in the console.

    Note

    Data and log backups are stored in independent backup storage and do not occupy instance storage space.

    What varies is the composition of the total backup size, the free quota, and the unit price. These values depend on which backup file types exist in backup storage. Select the tab that matches your instance.

    Physical backup

    These billing rules apply when the backup mode of the instance is physical backup and backup storage contains only physical backup files.

    If you switched the instance from snapshot backup to physical backup, the original snapshot backup files stay in backup storage until they expire and are deleted. For the period in which both file types exist, use the billing rules in the Coexistence of snapshot and physical backup files tab.

    Parameter

    Value

    Total backup size

    Sum of all physical backup and log backup sizes

    Free quota

    Instance storage space × 50%

    Physical backup unit prices vary by storage type (unit: USD/GB/hour):

    • Cloud disk instances: 0.00004

    • Local disk instances: 0.00020

    Example: Cloud disk instance in physical backup mode

    Instance details:

    • Instance storage space: 20 GB

    • Backup mode: physical backup

    • Total physical backup size: 30 GB (data backup: 20 GB, log backup: 10 GB)

    • Unit price: 0.00004 USD/GB/hour

      Fee calculation:

    1. Free quota = Instance storage space × 50% = 20 GB × 50% = 10 GB

    2. Total backup size = Data backup + Log backup = 20 GB + 10 GB = 30 GB

    3. Excess = Total backup size − Free quota = 30 GB − 10 GB = 20 GB

    4. Hourly fee = Excess × Unit price = 20 GB × 0.00004 USD/GB/hour = 0.0008 USD/hour

    Snapshot backup

    These billing rules apply when the backup mode of the instance is snapshot backup and backup storage contains only snapshot backup files.

    If you switched the instance from physical backup to snapshot backup, the original physical backup files stay in backup storage until they expire and are deleted. For the period in which both file types exist, use the billing rules in the Coexistence of snapshot and physical backup files tab.

    Parameter

    Value

    Total backup size

    Sum of all snapshot backup and log backup sizes

    Free quota

    Instance storage space × 200%

    The snapshot backup unit price is 0.00004 USD/GB/hour.

    Example: Cloud disk instance in snapshot backup mode

    Instance details:

    • Instance storage space: 20 GB

    • Backup mode: snapshot backup

    • Total snapshot backup size: 60 GB (data backup: 40 GB, log backup: 20 GB)

    • Unit price: 0.00004 USD/GB/hour

      Fee calculation:

    1. Free quota = Instance storage space × 200% = 20 GB × 200% = 40 GB

    2. Total backup size = Data backup + Log backup = 40 GB + 20 GB = 60 GB

    3. Excess = Total backup size − Free quota = 60 GB − 40 GB = 20 GB

    4. Hourly fee = Excess × Unit price = 20 GB × 0.00004 USD/GB/hour = 0.0008 USD/hour

    Coexistence of snapshot and physical backup files

    These billing rules apply during the transition period after you switch the backup mode of the instance, while both physical and snapshot backup files exist in backup storage.

    After the backup files of the original mode expire and are deleted, only one file type remains. From that point on, use the billing rules in the Physical backup tab or the Snapshot backup tab, depending on the current backup mode.

    Parameter

    Value

    Total backup size

    Sum of all physical backup, snapshot backup, and log backup sizes

    Free quota

    Instance storage space × 200%. The snapshot backup free quota applies during coexistence.

    Fees are calculated at the unit price of the backup mode after the switch:

    • Snapshot backup switched to physical backup: the physical backup unit price listed in the Physical backup tab

    • Physical backup switched to snapshot backup: the snapshot backup unit price listed in the Snapshot backup tab

    Example 1: Snapshot backup switched to physical backup

    Instance details:

    • Instance storage space: 20 GB

    • Backup mode: snapshot backup originally, now switched to physical backup

    • Snapshot backups retained from the original mode: 40 GB (data backup: 20 GB, log backup: 20 GB)

    • Physical backups generated after the switch: 20 GB (data backup: 10 GB, log backup: 10 GB)

    • Unit price: 0.00004 USD/GB/hour

      Fee calculation:

    1. Free quota = Instance storage space × 200% = 20 GB × 200% = 40 GB

    2. Total backup size = Total snapshot backup size + Total physical backup size = 40 GB + 20 GB = 60 GB

    3. Excess = Total backup size − Free quota = 60 GB − 40 GB = 20 GB

    4. Hourly fee = Excess × Unit price = 20 GB × 0.00004 USD/GB/hour = 0.0008 USD/hour

      During coexistence, the free quota is calculated at the 200% snapshot backup free quota, and the unit price is the unit price of the current mode, which is physical backup in this example.

    Example 2: Physical backup switched to snapshot backup

    Instance details:

    • Instance storage space: 20 GB

    • Backup mode: physical backup originally, now switched to snapshot backup

    • Physical backups retained from the original mode: 20 GB (data backup: 10 GB, log backup: 10 GB)

    • Snapshot backups generated after the switch: 40 GB (data backup: 20 GB, log backup: 20 GB)

    • Unit price: 0.00004 USD/GB/hour

      Fee calculation:

    1. Free quota = Instance storage space × 200% = 20 GB × 200% = 40 GB

    2. Total backup size = Total physical backup size + Total snapshot backup size = 20 GB + 40 GB = 60 GB

    3. Excess = Total backup size − Free quota = 60 GB − 40 GB = 20 GB

    4. Hourly fee = Excess × Unit price = 20 GB × 0.00004 USD/GB/hour = 0.0008 USD/hour

      During coexistence, the free quota is calculated at the 200% snapshot backup free quota, and the unit price is the unit price of the current mode, which is snapshot backup in this example.

    Usage notes

    For cloud disk instances in snapshot backup mode, control operations that replace cloud disks, such as rebuilding a secondary database, extend the snapshot chain of the instance and increase the following fees:

    • RDS basic backup fees (BackupCharged) — Same-region backup storage usage of the cloud disk instance grows, so same-region backup storage fees increase.

    • Cross-region backup network traffic fees (NetworkOutDuplicationSize) — Cross-region backup network traffic of the cloud disk instance grows, so cross-region backup network traffic fees increase.

    • Cross-region backup storage fees (DdrOssStorageSize) — Cross-region backup storage usage of the cloud disk instance grows, so cross-region backup storage fees increase. Cross-region backup storage fees differ across RDS database engines, so check the fees that apply to your engine.

      For example, if certain DDL operations on an RDS cloud disk instance cause excessive secondary database latency, the system may automatically rebuild the secondary database to protect stability. The rebuild extends the snapshot chain, which increases backup storage usage and network traffic, and therefore raises the preceding fees.

    Reduce backup fees

    • Reduce the backup size

      Reduce the number of backup sets by lowering the backup frequency, or by shortening the backup retention period so that the system automatically deletes existing backups. Manual deletion of backup sets is not supported.

    • Increase the free backup quota

      The free quota is proportional to the instance storage space, so expanding the storage space raises the free backup quota of the instance and reduces the portion of the total backup size that is billed. For example, if the backup mode is snapshot backup and you expand the instance storage space from 150 GB to 300 GB, the free quota rises from 300 GB to 600 GB.

    View backup bills

    1. On the Bill Details page, select Billing Item and Details, enter the instance name, instance ID, or bill ID, and click Search.

    2. Find the details whose billing item is Instance Backup.

    FAQ

    • Q: The automatic backups of my RDS instance have exceeded the free quota and are now billed. How do I turn off the backup feature?

      A: Automatic backups of an RDS instance are enabled by default and cannot be turned off. To reduce charges, modify the automatic backup policy to delete existing backups or to generate fewer new backups.

    • Q: I shortened the backup retention period from x days to y days, but the backup size has not changed. Why?

      A: If no existing backup files are older than y days, no files are deleted and the backup size remains unchanged. The retention period removes only the backups that have exceeded the specified duration.

    • Q: Where do I view the total backup size and the free backup quota of an ApsaraDB RDS for SQL Server instance?

      A: Go to Basic Information > Instance Resources > Backup Usage on the instance details page in the console.

    • Q: Why is the total snapshot backup size larger than the actual data file size?

      A: Snapshot backup size is calculated from cloud disk storage blocks, not from the actual data volume of the files. When the system calculates the snapshot backup size, it counts the total capacity of all non-empty storage blocks. Cloud disks allocate storage blocks in a fixed unit, such as 4 MB, so scattered writes increase the number of non-empty blocks. For example, 3 MB of data may occupy two, three, or even more storage blocks. In such cases, the total snapshot backup size can exceed the actual data volume.