Billing rules of RDS storage plans and how to purchase a storage plan-ApsaraDB RDS(RDS)-阿里云帮助中心

A storage plan is a type of upfront resource plan offered by RDS. It can offset the RDS MySQL, RDS PostgreSQL, RDS SQL Server, and RDS MariaDB instances' storage space, backup storage (instance backups, long-term backups, and geo-redundancy backups) and SQL Audit usage. The offset portion is no longer billed; only the excess is billed on an hourly basis. This topic describes the billing rules of RDS storage plans and how to purchase a storage plan.

Notes

Only Alibaba Cloud accounts can purchase storage plans.
Storage plans cannot be upgraded or renewed.
The price of a storage plan is subject to the purchase page.
Currently, storage plans are available only in some of the following regions in the Chinese mainland.
China (Hangzhou), China (Shanghai), China (Nanjing - local region - being phased out), China (Qingdao), China (Beijing), China (Zhangjiakou), China (Hohhot), China (Ulanqab), China (Shenzhen), China (Heyuan), China (Guangzhou), China (Chengdu).
A storage plan can offset:
- The storage space of pay-as-you-go instances (excluding standard SSDs and Premium ESSDs).
- The backup storage of subscription and pay-as-you-go instances (excluding standard SSDs and Premium ESSDs) and SQL Audit usage.

Applicable items

Note

Subscription, pay-as-you-go, and Serverless are three distinct and independent billing methods. When you use a storage plan, offsets are made strictly according to the following rules. For example, a storage plan can offset the storage space of pay-as-you-go instances (excluding standard SSDs and Premium ESSDs), but it cannot offset the storage space of Serverless instances.

Applicable item	Description
Storage space	Offsets the storage space of pay-as-you-go RDS instances (excluding standard SSDs and Premium ESSDs).
Backup storage	Offsets the long-term backups (backups older than two years), geo-redundancy backup storage, and instance backups that exceed the free quota of pay-as-you-go and subscription RDS instances (excluding standard SSDs and Premium ESSDs). Note You can view the free backup quota provided by RDS in Basic Information > Instance Resources > Backup Usage on the instance details page in the console. Geo-redundancy backup storage can be offset only for RDS MySQL Premium Local SSD instances, RDS SQL Server instances, and RDS PostgreSQL instances (Billing item code: DdrOssStorageSize). The geo-redundancy backup storage fees of RDS MySQL cloud disk instances (Billing item code: BackupStorageSize) can be offset by a DBS storage plan.
SQL Audit usage	Offsets the SQL Audit (SQL Explorer) usage of pay-as-you-go and subscription RDS instances. The following engines are involved: RDS MySQL: Use SQL Explorer and Audit. RDS SQL Server: Use the SQL Audit feature. RDS PostgreSQL: Use the SQL Audit feature. Note Fees generated by the SQL Explorer and Audit feature of RDS MySQL are charged by DAS in some regions. A storage plan can offset fees only in the regions that are charged by the RDS side. For more information, see Use SQL Explorer and Audit. For RDS PostgreSQL, after the SQL Audit feature is upgraded to the SQL Explorer and Audit feature of DAS Enterprise Edition, storage plans can no longer be used to offset the fees.

Offset rules

Rule

Description

Offset method

Every hour, the total amount of the following types of space of an instance is counted and offset from the purchased storage plan capacity based on the offset factor. If the offset amount exceeds the total capacity of the storage plan, the excess is billed on a pay-as-you-go basis.
Note
The operational costs of different applicable items vary, so offset factors are defined to balance the costs.
- The storage space of pay-as-you-go instances.
- Instance backups, long-term backups, and geo-redundancy backup storage.
- SQL Audit usage.
The full capacity of the storage plan is used for offset every hour.
For example, if you purchase a 100 GB storage plan for a duration of one month, 100 GB of the storage plan capacity is available for offset every hour within that month.

For the specific offset method, see Storage plan offset example.

Offset order

The priority of applicable items within an RDS storage plan:
Storage space of a pay-as-you-go primary instance > Storage space of a pay-as-you-go read-only instance > Backups of a pay-as-you-go instance > SQL Audit of a pay-as-you-go primary instance > SQL Audit of a pay-as-you-go read-only instance > Long-term backups of a pay-as-you-go instance > Geo-redundancy backup storage of a pay-as-you-go instance > Backups of a subscription instance > SQL Audit of a subscription primary instance > SQL Audit of a subscription read-only instance > Long-term backups of a subscription instance > Geo-redundancy backups of a subscription instance
The priority when an RDS savings plan and an RDS storage plan are used together:
RDS storage plan takes priority over RDS savings plan.

Storage plan offset example

Assume that a user has an RDS primary instance (cloud disk ESSD PL1, basic series) with 60 GB of instance storage space, and also has a 500 GB long-term backup (a backup older than two years). The user then purchases a 100 GB storage plan. The storage plan is offset as follows:

Calculate the total storage space that the storage plan can offset: 100 GB / 1.24 = 80.645 GB.
After the storage plan offsets the instance storage space, the remaining capacity is: (80.645 GB - 60 GB) × 1.24 = 25.5998 GB.
The long-term backup space that the remaining storage plan capacity can offset is 25.5998 GB / 0.1 = 255.998 GB, which is not enough to offset the 500 GB long-term backup. The storage plan first offsets 255.998 GB of long-term backup.
The remaining long-term backup 500 GB - 255.998 GB = 244.002 GB is billed on a pay-as-you-go basis as usual.

Note

The storage space offset factor of a primary instance that uses cloud disk ESSD PL1 of the basic series is 1.24, and the long-term backup offset factor is 0.1. For more information, see Offset factor details.
The storage space of the primary instance is offset before the long-term backup. For more information, see Offset rules.
You can go to the Basic Information page of the instance and, in the Usage Statistics section, view the actual storage space and backup usage of the instance.

Purchase an RDS storage plan

Go to the RDS purchase page.
Billing Method: select Storage Plan.

Configure the following parameters.

Parameter	Description
Region	Currently, you can select only Chinese Mainland General. The Chinese mainland includes the following regions: China (Hangzhou), China (Shanghai), China (Nanjing - local region - being phased out), China (Qingdao), China (Beijing), China (Zhangjiakou), China (Hohhot), China (Ulanqab), China (Shenzhen), China (Heyuan), China (Guangzhou), China (Chengdu).
Storage Plan Specification	You can purchase storage plans of the following specifications: 100 GB, 200 GB, 300 GB, 500 GB, 1000 GB, 2000 GB, 5000 GB, 10000 GB.
Activation Time Selection	You can select Effective Immediately After Order or Effective at Specified Time (Hourly). When you select Effective at Specified Time (Hourly), you must Specify Time.

Set the Subscription Duration, and then click Buy Now.
The subscription duration of a storage plan ranges from 1 month to 11 months, and from 1 year to 5 years.
Note
The longer the subscription duration, the higher the discount:
- A 1-year subscription duration receives a 15% discount.
- A 2-year subscription duration receives a 30% discount.
- A subscription duration of 3 to 5 years receives a 50% discount.

View storage plan usage details

Log on to Expenses and Costs.
Choose Account > Resource Plan.
On the Resource Plan page, set Resource Dimension to Resource Plan.
In the Instance Summary tab, you can view the total capacity and remaining capacity of the resource plan (Product Name is RDS Storage Resource Plan).
Click the Usage Details tab to view the specific list of resource plan offsets (Product Name is RDS Storage Resource Plan).
Note
You can view the cost details of the instance on the Bills > Bill Details page, and verify the offset of the resource plan through the cost details.

Offset factor details

Storage space

Billable item	Instance type	Storage type	Series	Offset factor
Storage space	Primary instance	Premium Local SSD	High-availability series	1
		Premium Local SSD	RDS Enterprise Edition	1.47
		Cloud disk ESSD PL1	Basic series	1.24
			High-availability series	2
			MySQL Cluster Edition (single-node)	1
			SQL Server Cluster Edition	2
		Cloud disk ESSD PL2	Basic series	2.47
			High-availability series	4
			MySQL Cluster Edition (single-node)	2
			SQL Server Cluster Edition	4
		Cloud disk ESSD PL3	Basic series	4.94
			High-availability series	7.94
			MySQL Cluster Edition (single-node)	4
			SQL Server Cluster Edition	7.94
	Read-only instance	Premium Local SSD	High-availability series/RDS Enterprise Edition	0.59
		Cloud disk ESSD PL1	Basic series/High-availability series/RDS Enterprise Edition	1.24
		Cloud disk ESSD PL2	Basic series/High-availability series/RDS Enterprise Edition	2.47
		Cloud disk ESSD PL3	Basic series/High-availability series/RDS Enterprise Edition	4.94

Backup storage

Billable item	Instance type	Backup type	Offset factor
Long-term backup (backups older than two years)	Primary instance	-	0.1
Geo-redundancy backup storage	Primary instance	-	0.59
Instance backup	Primary instance	Physical backup	0.59
Instance backup	Primary instance	Snapshot backup	0.15

SQL Audit

Billable item	Instance type	Audit type	Offset factor
SQL Audit	Primary instance/read-only instance	Long period (30 days)	4.71
SQL Audit	Primary instance/read-only instance	Short period (7 days)	7.06

FAQ

Q: I have purchased a pay-as-you-go RDS instance with the storage space set to 100 GB. If I purchase a 100 GB storage plan, can it offset the fees for the instance storage space?
A: Yes. A storage plan can offset the storage space of pay-as-you-go instances. The storage plan is used for offset first, and pay-as-you-go billing applies when the remaining storage plan space is insufficient.
Q: For backup storage, if I purchase both an RDS savings plan and an RDS storage plan, what is the offset order?
A: When an RDS savings plan and an RDS storage plan are used together, RDS storage plan takes priority over RDS savings plan.
Q: Can the backup capacity be expanded all at once?
A: No. The free quota of RDS backups is tied to the instance storage space (twice the storage for cloud disk instances and 50% of the storage for local disk instances) and cannot be modified separately. When the backup usage exceeds the free quota, you can purchase an RDS storage plan to offset the fees for the excess backup storage. To adjust the backup frequency, go to the Backup and Restoration > Backup Policy page in the instance details of the RDS console to modify the backup cycle and retention days. After the excess billing is generated, purchase a storage plan to offset it.