The true incremental-forever backup feature of Database Backup (DBS) allows you to use the combination of a full backup and several synthetic backups to back up an Oracle database. The feature helps reduce backup costs and resource consumption during backups.

Background information

How the true incremental-forever backup feature works:

  1. Full backup: It is Recovery Manager (RMAN) level 0 backup on an Oracle database. All data files, archived log files, SPFILEs, and control files in the Oracle database are backed up in a full backup.
  2. Synthetic backup:
    1. Take a snapshot and mount it locally: Take a snapshot of the last full backup set or synthetic backup set, and then mount (clone) the snapshot to a self-managed database by using FUSE.
    2. Create an incremental backup: Back up data blocks that have changed after the last full backup or synthetic backup and save them as an incremental backup file.
    3. Synthesize data: Execute the RMAN RECOVER COPY OF DATABASE WITH TAG 'DBS-specific tag' SQL statement to read the incremental backup data in the previous step, merge the incremental backup data into the full backup data, and then write the merge result to overwrite the snapshot of the last full backup set.
      Note The new full backup set that is generated after the merge does not affect the last full backup set.
    4. Unmount the mount point of the self-managed database.
Note You can configure the number of full backups to be performed each week in DBS. DBS first performs a full backup in each week, and then performs synthetic backups for the subsequent backups. After a full backup is complete in a week, the generated backup set is the starting point for the subsequent synthetic backups of the week.
The synthetic backup method provides the following advantages:
  • Fewer costs: This method backs up and stores less data and consumes less bandwidth for data transmission.
  • Lower resource consumption: Compared with a full backup, a synthetic backup requires less disk IOPS of the source database.
  • Support for mounting: After the snapshot of a synthetic backup set is mounted to a self-managed database, you can restore the backup data in seconds.

Public preview statement

The true incremental-forever backup feature is in public preview. To use this feature, scan the following QR code to join the DingTalk group whose ID is 35585947.

QR code to join the DingTalk group whose ID is 35585947

For Oracle backup schedules that are created during the public preview period, the Backup set mode. parameter must be set to Sandbox instance mount backup, and the sandbox feature is enabled by default. You can create free sandbox instances for backup schedules during the public preview period. For more information, see Overview.

Note The sandbox feature cannot be disabled during the public preview period.

Prerequisites

  • The Oracle database version is 11 to 19.
  • The Oracle database uses the single-instance or Oracle RAC architecture. The Oracle Data Guard physical standby architecture is not supported.
    Note Take note of the following points when you back up an Oracle RAC database:
    • To perform a successful backup, you must check the control files, SPFILEs, data files, archived log files, and redo log files of Oracle databases before you back up the data.
    • To back up the entire RAC, you need only to deploy a backup gateway on one of the servers where the Oracle RAC database is deployed and enter the Oracle SID of the server.
  • The server where the Oracle database is located uses the Linux operating system and has a backup gateway installed. For more information, see Add a backup gateway.
  • FUSE is installed on the server where the Oracle database is located.
  • The Oracle database to be backed up is running in archive mode. For more information, see Enable archive mode.
  • The Oracle System ID (SID) is obtained. For more information, see Obtain the Oracle SID.
  • The block change tracking feature is enabled for the Oracle database.
    Note
    1. You can execute the SELECT status FROM v$block_change_tracking; SQL statement to check whether the block change tracking feature is enabled. The feature is disabled by default.

      A value of ENABLED indicates that the feature is enabled. A value of DISABLED indicates that the feature is disabled.

    2. You can execute the following SQL statement to enable the block change tracking feature:
      ALTER DATABASE ENABLE BLOCK CHANGE TRACKING USING FILE <Path of the block change tracking file> REUSE;

Create a backup schedule

For more information, see Purchase a backup schedule.

Note When you purchase a backup schedule, set the Database Type parameter to Oracle and the Backup Method parameter to Physical Backup.

Configure the backup schedule

  1. Log on to the DBS console.
  2. In the left-side navigation pane, click Backup Schedules. On the Backup Schedules page, select a region in the upper-left corner.
  3. On the Backup Schedules page, find the backup schedule that you want to configure and click Configure Backup Schedule in the Actions column.
  4. In the Configure Backup Source and Destination step of the Configure Backup Schedule wizard, configure the backup source and destination, and click Next in the lower-right corner of the page.
    Section Parameter Description
    N/A Schedule Name The name of the backup schedule. DBS generates a backup schedule name. We recommend that you set a descriptive name that is easy to identify. Backup schedule names do not have to be unique.
    Backup Source Information Backup Mode The method used to back up data. By default, the backup method that you selected when you purchased the backup schedule is used. In this example, the physical backup mode is used.
    Instance Region The region where the instance that you want to back up resides.
    Backup Gateway The backup gateway that is installed to back up data. For more information about how to install a backup gateway, see Add a backup gateway.
    Database Type The type of the database that you want to back up. Default value: Oracle.
    SID The Oracle SID of the destination server. For more information, see Obtain the Oracle SID.
    Oracle Home The absolute path of ORACLE_HOME. For more information, see Obtain the database program directory.
    Note This parameter is optional.
    Backup Destination Information Backup Storage Type The type of storage used to back up data. Only DBS built-in storage is supported for the true incremental-forever backup feature.
    Storage Encryption The method used to encrypt the stored data. Valid values:
    • Encrypted (recommended): DBS uses AES-256, one of the advanced encryption standard ciphers, to encrypt the stored data.

      The server-side encryption feature is used in OSS. When you upload an object to a bucket for which server-side encryption is enabled, OSS encrypts and stores the object. When you download the encrypted object from OSS, OSS decrypts the object and returns the decrypted object to you. For more information, see Server-side encryption.

    • Non-encrypted: The backup data is not encrypted.
  5. In the Edit Backup Objects step, Back Up Entire Instance is selected by default. Click Next.
    Note If you back up an entire database, the permission data and stored procedures are also backed up.
  6. In the Configure Backup Time step, set the parameters that are described in the following table and click Next.
    Parameter Description
    Full-scale Backup Frequency The frequency of the backup schedule. Valid values: Periodic Backup and Single Backup.
    Full Data Backup Recurrence

    The days of the week on which DBS runs the backup schedule. Select at least one day of the week.

    Note DBS first performs a full backup in each week, and then performs synthetic backups for the subsequent backups.
    Start At

    The start time of the backup, such as 01:00. We recommend that you set a time during off-peak hours.

    Note If a previous full data backup is not finished at the start time of the next backup, DBS skips the next backup.
    Real-Time Transaction Log Backup

    Specifies whether to enable incremental backup.

    This parameter is displayed only when you set the Full-scale Backup Frequency parameter to Periodic Backup.

    Maximum Concurrent Threads for Full Data Backup

    The maximum number of concurrent threads available for a full data backup. You can set this parameter to adjust the backup speed. For example, reduce the number of backup threads to minimize the impact on the database.

    Backup network speed limit

    The limit on the network bandwidth. You can set the limit based on your needs. Default value: 0, which indicates that the network bandwidth is unlimited.

    Note When you back up the production database, we recommend that you configure throttling for the backup to reduce impacts on the production database.
    Incremental Backup Interval

    The interval at which incremental backups are performed. DBS performs incremental backups based on your settings. If you set the interval to 10 minutes, DBS performs an incremental backup every 10 minutes.

    This parameter is displayed only when you set the Incremental real-time backup parameter to Enable.

    Delete Logs upon Backup Success Specifies whether to automatically delete archived log files that are backed up. Valid values:

    If you select Enable, you must set the Log Retention Period parameter.

    Log Retention Period Specifies that DBS deletes the log files archived before this period after a successful backup. Default value: 7 days. If you set this parameter to the default value, DBS deletes the log files archived before seven days after a successful backup.

    This parameter is displayed only when the Delete Logs upon Backup Success parameter is set to Enable.

    Enable compression Specifies whether to enable compression during backup. Valid values:
    • Enable (recommended): Data is compressed during backup to reduce storage space.
    • Disable: Data is not compressed during backup.
    Backup set mode Only the Sandbox instance mount backup mode is supported. DBS uses the RMAN tool to perform image copy backup. Backup data is streamed and sent to OSS by using the FUSE protocol, instead of being stored in disks. After the sandbox feature is enabled, the backup data can be mounted in seconds.

    You must install FUSE on your server to ensure successful backup tasks.

  7. In the Edit Lifecycle step, configure the lifecycle for full backup data in the Configure Full Data Backup Lifecycle section.
    If you set the Incremental real-time backup parameter to Enable in Step 6, you must configure the lifecycle for incremental backup data. For more information about the lifecycle rules of backup data, see How do I manage the lifecycle rules of backup sets?.
  8. After the configurations are complete, click Precheck in the lower-right corner of the page.
  9. If the Precheck Passed message appears, click Start Task.
    Note When the status of the backup schedule changes to Running, the backup schedule takes effect. You can view the backup task on the Backup Schedules page. For more information, see View backup schedules.

What to do next

DBS allows you to restore an Oracle database to a different machine, to a different directory of the source machine, or to the same directory of the source machine. For more information, see Restore an Oracle database from a physical backup.