This topic describes how to enable the snapshot backup feature for an ApsaraDB MyBase for SQL Server instance. Compared with the physical backup feature, the snapshot backup feature supports a higher backup speed and larger amounts of data.

Prerequisites

The instance uses enhanced SSDs (ESSDs).

Comparison between snapshot backups and physical backups

Item Physical backup Snapshot backup
Backup speed The backup speed is fast. However, the restoration speed varies based on the specifications of your RDS instance. The backup speed is extremely fast. The speed of creating a snapshot backup is approximately twice the speed of creating a physical backup.
Note When you create a snapshot backup for the first time, ApsaraDB RDS backs up all the data of your RDS instance. The backup process may require a long period of time.
Backup frequency Physical backups support the following two backup frequencies:
  • Same as Data Backup
  • Every 30 minutes
 The Backup Frequency is fixed to Every 30 minutes and cannot be changed.
Restoration speed The restoration speed is fast. However, the restoration speed varies based on the specifications of your RDS instance. The restoration speed is extremely fast. The restoration speed is not affected by the amount of data. The speed of restoring data from a snapshot backup is higher than the speed of restoring data from a physical backup.
  • Restore data to a new RDS instance
    • The time that is required to restore data from a data backup file is approximately 30 minutes. This includes the time that is required to create an RDS instance and the time that is required to restore the data from the data backup file.
    • The time that is required to restore data to a point in time varies based on the log backup file that is used. This includes the time that is required to create an RDS instance and the time that is required to restore the data from the log backup file.
  • Restore data to an existing RDS instance
    • The time that is required to restore data from a data backup file is approximately 10 minutes.
    • The time that is required to restore data to a point in time varies based on the log backup file that is used.
Note The logs that are restored are generated between the point in time at which the closest snapshot backup file is generated and the point in time to which you want to restore data.
Amount of data supported Up to 4 TB of data is supported. Up to 16 TB of data is supported.
Impact on instance performance A large number of resources are occupied. This has a significant impact on the performance of your RDS instance. We recommend that you perform a physical backup during off-peak hours. Only a small number of I/O resources are occupied. This does not significantly affect the performance of your RDS instance. You can perform a snapshot backup at any time.
Download of backup files Physical backup files can be downloaded. Snapshot backup files cannot be downloaded.

Benefits

Data can be restored from physical backup files at a speed of up to 20 MB per second. Each physical backup can contain up to 4 TB of data. If you restore a large amount of data, the restoration process may require a long period of time. ApsaraDB MyBase for SQL Server provides the snapshot backup feature that is developed based on Microsoft Volume Shadow Copy Service (VSS). The snapshot backup feature can back up data at a high speed and ensure the consistency and integrity of data.

Snapshot backups provide the following benefits:

  • Each snapshot backup supports up to 16 TB of data.
  • Snapshot backups support a higher backup speed than physical backups.
  • Snapshot backups do not occupy CPU or memory resources. Compared with physical backups, snapshot backups occupy less I/O resources. When snapshot backups are being created, the performance of your RDS instance is not significantly affected.
  • Compared with physical backups, snapshot backups support a higher restoration speed, reduced recovery time objective (RTO), and improved fault resistance for your database service.
  • After you enable snapshot backups, you can still perform physical backups to back up your RDS instance. For more information, see Manually back up your RDS instance.

Limits

  • Snapshot backup files cannot be stored in a region that is different from the region where your RDS resides. For more information, see Enable cross-region backups for an ApsaraDB RDS for SQL Server instance.
  • You can change the backup method of your RDS instance from Physical Backup to Snapshot Backup. However, you cannot change the backup method of your RDS instance from Snapshot Backup to Physical Backup.
  • Snapshot backups support only full backups. Snapshot backups do not support individual databases or tables.
  • Snapshot backup files cannot be downloaded.

Enable the snapshot backup feature

By default, an instance uses the physical backup method. You can change the backup method to snapshot backup.

  1. Log on to the ApsaraDB MyBase console.
  2. In the upper-left corner of the page, select the region where you want to create a dedicated cluster.
  3. In the left-side navigation pane, choose Instances > SQL Server.
  4. Find the instance that you want to manage and click Details in the Actions column.
  5. In the left-side navigation pane, click Backup and Restoration.
  6. On the page that appears, click Backup Settings. On the Backup Settings tab, click Edit next to Data Backup Settings.
  7. In the dialog box that appears, set the Backup Method parameter to Snapshot Backup and click Save.
    Notice
    • After you set the Backup Method parameter to Snapshot Backup, you cannot change the value of the parameter to Physical Backup.
    • After you set the Backup Method parameter to Snapshot Backup, the Backup Frequency parameter is automatically set to Every 30 Minutes and the value cannot be changed.