This topic describes how to view and manage the backup size and billable items for RDS SQL Server. You can adjust your backup policy as needed to reduce backup fees.
Billable items
Billable item | Billable item code | Associated product | References |
Storage for regular backups | BackupCharged | RDS | |
Storage for cross-region backups | DdrOssStorageSize | RDS | |
Traffic that is consumed by cross-region backups | NetworkOutDuplicationSize | Database Backup (DBS) | |
Internet traffic that is consumed for backup downloads | NetworkOutSize | Database Backup (DBS) |
Billing rules
If the total backup size does not exceed the free quota, no fees are charged for backups. Fees are charged for the backup size that exceeds the free quota on a pay-as-you-go basis. The billing rules for different scenarios are as follows:
Physical backup
When the backup mode of an instance is physical backup and only physical backup files exist in the backup space, refer to the following billing rules:
When you switch your instance from snapshot backup to physical backup:
If the original snapshot backup files have not expired and been deleted, both physical backup files and snapshot backup files will exist in the backup space. During this period, refer to the billing rules for the "Coexistence of snapshot backup and physical backup files" scenario.
If the original snapshot backup files have expired and been deleted, only physical backup files remain in the backup space. Refer to the billing rules for this scenario.
Billing formula | Hourly backup fee = (Total backup size - Free quota) × Unit price for physical backup |
Total backup size | The sum of all physical backup and log backup sizes. You can view this in the section on the instance details page in the console. |
Free quota (GB) | Total instance storage space × 50% |
Unit price for physical backup | The unit price varies by storage type, as follows (unit: USD/GB/hour):
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Billing example |
Snapshot backup
When the backup mode of an instance is snapshot backup and only snapshot backup files exist in the backup space, refer to the following billing rules:
When you switch your instance from physical backup to snapshot backup:
If the original physical backup files have not expired and been deleted, both physical backup files and snapshot backup files will exist in the backup space. During this period, refer to the billing rules for the "Coexistence of snapshot backup and physical backup files" scenario.
If the original physical backup files have expired and been deleted, only snapshot backup files remain in the backup space. Refer to the billing rules for this scenario.
Billing formula | Hourly backup fee = (Total backup size - Free quota) × Unit price for physical backup |
Total backup size | The sum of all snapshot backup and log backup sizes. You can view this in the section on the instance details page in the console. |
Free quota (GB) | Total instance storage space × 200% |
Unit price for snapshot backup | 0.00004 (unit: USD/GB/hour) |
Billing example |
Coexistence of snapshot backup and physical backup files
When the backup mode of an instance is switched from snapshot backup to physical backup, or from physical backup to snapshot backup:
If the original snapshot/physical backup files have expired and been deleted, and only one type of backup files (all physical backups or all snapshot backups) remains in the backup space, refer to the billing rules for the "Physical backup" or "Snapshot backup" scenario.
If the original snapshot/physical backup files have not expired and been deleted, and both physical backup files and snapshot backup files exist in the backup space, refer to the billing rules for this scenario during this period.
Billing formula | Hourly backup fee = (Total backup size - Free quota) × Unit price for backup |
Total backup size | The sum of all physical backup, snapshot backup, and log backup sizes. You can view this in the section on the instance details page in the console. |
Free quota (GB) | Total instance storage space × 200% |
Unit price for backup | The fee is calculated based on the unit price of the backup mode after switching:
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Billing example |
Notes
Data and log backups are stored in an independent backup space and do not occupy instance storage space.
Backup fees are only related to backup size, not to instance storage space usage. When calculating backup fees, check the total backup size rather than the storage space usage.
Control operations involving cloud disk replacement (such as secondary database rebuilding) will have the following impacts on cloud disk instances in snapshot mode:
The backup storage of the RDS instance that uses cloud disks increases. As a result, the backup storage fees increase. The code of the billable item is BackupCharged.
The traffic consumed by cross-region backups of the RDS instance that uses cloud disks increases. As a result, the traffic fees of cross-region backups increase. The code of the billable item is NetworkOutDuplicationSize.
The cross-region backup storage of the RDS instance that uses cloud disks increases. As a result, the fees generated for cross-region backup storage increase. The code of the billable item is DdrOssStorageSize.
NoteFor example, when a user performs certain DDL operations on an RDS cloud disk instance that cause excessive secondary database latency, the system may automatically trigger secondary database rebuilding to ensure product stability. This operation can lead to an increase in snapshot chains, resulting in growth of backup storage and network traffic, which causes an increase in the above fees.
Reduce/save backup fees
Reduce backup size
You can reduce the backup frequency to decrease the number of backup sets, or shorten the backup retention period to allow the system to automatically delete existing backups (manual deletion of backup sets is not supported).
Increase the free backup quota
The free quota is related to storage space. Expanding the storage space can increase the free backup quota of an instance. For example, when the backup method is snapshot backup, if you expand the instance storage space from 150 GB to 300 GB, the free quota will increase from 300 GB to 600 GB.
FAQ
Q: The automatic backup of my RDS instance has exceeded the free quota and is now being charged. How can I turn off the backup feature?
A: The default backup feature of RDS is enabled by default and cannot be turned off. However, you can modify the automatic backup policy to delete existing backups or reduce the generation of new backups.
The backup retention period of my RDS instance is shortened from x days to y days. Why does the size of backup files remain unchanged?
If no backup files are retained for more than y days, no backup files are deleted and the size of backup files remains unchanged after you shorten the backup retention period.
Q: Where can I view the total backup size and free backup quota for my RDS SQL Server instance?
A: You can view this in the section 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 backups are calculated based on cloud disk storage blocks rather than actual data file size. When calculating snapshot backup size, the system counts the total capacity of all non-empty storage blocks. Since cloud disk storage blocks are allocated in fixed sizes (such as 4 MB), when data is written in a scattered manner (for example, 3 MB of data may occupy 2, 3, or even more storage blocks), the number of non-empty blocks increases. In such cases, the total snapshot backup size may be larger than the actual data size.