ApsaraDB RDS for SQL Server lets you move infrequently accessed databases off expensive cloud disks into low-cost OSS cold storage — with no instance downtime. When you need to query the data again, convert the database back to online with a few clicks.
Cold storage databases cannot be accessed directly. After a database is converted to cold storage, all read and write operations are blocked until you convert it back to an online database.
Prerequisites
Before you begin, ensure that your RDS instance meets the following requirements:
Edition: RDS Basic Edition
Storage type: Enterprise SSD (ESSD)
Billing method: Subscription or pay-as-you-go (Serverless is not supported)
Region: not Thailand (Bangkok), South Korea (Seoul), UK (London), SAU (Riyadh - Partner Region), or UAE (Dubai)
How it works
Data archiving uses SQL Server's native database detachment and attachment feature to move data files between cloud disks and OSS buckets.
When you archive a database:
The database is detached from the cloud disk.
Data files are transferred from the cloud disk to an OSS bucket.
The database appears as a cold storage database in the console — inaccessible until restored.
Restoring a cold storage database reverses this process: files move back from OSS to the cloud disk, and the database is reattached and brought online.
Limitations
| Limitation | Details |
|---|---|
| Read and write access | Blocked on cold storage databases. Convert back to online to resume access. |
| Backup and restore | Not supported for cold storage databases. Only databases in existing backup sets can be restored. If you restore an instance, cold storage databases are excluded from the restored instance. |
| Edition upgrade | Basic Edition instances with ESSD storage and data archiving enabled cannot be upgraded to other editions. |
| Same-name conflict | If an online and a cold storage database share the same name, neither can be deleted. Use the ModifyDatabaseConfig API operation to restore the cold storage database under a different name. |
| Maximum cold storage databases | 15 per instance |
Billing
Archived data is billed on a pay-as-you-go basis for OSS cold storage.
Basic Edition
| Region | Unit price |
|---|---|
| China (Zhangjiakou), China (Hohhot), China (Ulanqab), China (Guangzhou), China (Hangzhou), China (Shenzhen), China (Chengdu), China (Qingdao), China (Shanghai), China (Beijing), and China (Heyuan) | USD 0.000032 per GB-hour |
| China (Hong Kong), Singapore, Germany (Frankfurt), Japan (Tokyo), and Indonesia (Jakarta) | USD 0.000034 per GB-hour |
| US (Virginia) | USD 0.000054 per GB-hour |
| Malaysia (Kuala Lumpur) | USD 0.000057 per GB-hour |
| US (Silicon Valley) and Philippines (Manila) | USD 0.000058 per GB-hour |
Example: A 500 GB database archived for 30 days in China (Shanghai) costs approximately: 500 GB x 720 hours x USD 0.000032 = USD 11.52.
Archive and restore a database
The data archiving feature is enabled by default — no setup required. Follow the steps below to archive or restore a database.
Convert an online database to a cold storage database
Go to the Instances page. In the top navigation bar, select the region where the RDS instance resides, then click the instance ID.
In the left-side navigation pane, click Databases.
In the Actions column of the target database, click More > Convert Online Database To Cold Storage Database.
Click OK, then refresh the page. The database status changes from Running to Converting to Cold Storage. The conversion time depends on the size of the database files. Large databases may take longer.
Convert a cold storage database to an online database
Go to the Instances page. In the top navigation bar, select the region where the RDS instance resides, then click the instance ID.
In the left-side navigation pane, click Databases.
In the Actions column of the target database, click More > Convert Cold Storage Database To Online Database.
Click OK, then refresh the page. The cold storage database enters the conversion stage.
What's next
Use the ModifyDatabaseConfig API operation to automate archiving and restoration workflows, or to resolve same-name conflicts by restoring a cold storage database under a different name.
For supported storage types, see Storage types.
For data restoration from backup sets, note that cold storage databases are not included in restored instances.
References
You can also call the ModifyDatabaseConfig API operation to convert databases between online and cold storage states.
For more information about the storage types that ApsaraDB RDS for SQL Server supports, see Storage types.