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Database Backup:Create a true incremental-forever backup for an Oracle database

Last Updated:Dec 20, 2023

Database Backup (DBS) allows you to create a true incremental-forever backup for an Oracle database. Full backups and synthetic backups are supported to reduce backup costs and resource overheads.

Background information

How the true incremental-forever backup feature works:

  1. Full backup: The level-0 backup of an Oracle database by using the Recovery Manager (RMAN) tool. All data files, archived log files, server parameter files (SPFILEs), and control files in the Oracle database are backed up in a full backup.

  2. Synthetic backup:

    1. Create a snapshot and mount the snapshot to an on-premise self-managed database: The snapshot of the last full backup set or synthetic backup set is created and mounted (cloned) to the database by using the Filesystem in Userspace (FUSE) protocol.

    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 merging operation does not affect the last full backup set.

    4. Unmount the mount target 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 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 benefits:

  • Reduced 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.

Prerequisites

  • The Oracle database version is 11 to 19.

  • The Oracle database uses the single-instance or Oracle Real Application Clusters (RAC) architecture. Oracle databases that are in the Data Guard physical standby architecture are not supported.

    Note

    Take note of the following items if you want to 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. For more information, see Prepare for physical backup of an Oracle database.

    • 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 in which the Oracle database resides uses the Linux operating system, and a backup gateway is installed on the destination server. For more information, see Install a backup gateway.

  • The FUSE protocol is installed on the database server.

  • The archive mode is enabled for the Oracle database to be backed up. For more information, see the Enable the archive mode section of the "Prepare for physical backup of an Oracle database" topic.

  • The SID of the destination Oracle database is obtained. For more information, see the Obtain the SID of an Oracle database section of the "Prepare for physical backup of an Oracle database" topic.

  • 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. By default, the feature is disabled.

      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;

Public preview statement

The true incremental-forever backup feature is in public preview. To use this feature, 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.

Step 1: Create a backup schedule

For more information, see Purchase a backup schedule.

Note

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

Step 2: Configure the backup schedule

  1. Log on to the Database Backup (DBS) console.

  2. In the left-side navigation pane, click Backup Schedules. In the top navigation bar, select a region.

  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.

    image.png

    Section

    Parameter

    Description

    N/A

    Schedule Name

    The name of the backup schedule. DBS automatically generates a backup schedule name. We recommend that you set a descriptive name that is easy to identify. Backup schedule names do not need to be unique.

    Backup Source Information

    Backup Mode

    The method that is used to back up data. By default, the backup method that you selected when you purchased the backup schedule is used. In this example, Physical Backup is used.

    Instance Region

    The region in which the database that you want to back up is deployed.

    Backup Gateway

    The backup gateway that is installed to back up data. For more information about how to install a backup gateway, see Install a backup gateway.

    Database Type

    The type of the database that you want to back up. Default value: Oracle.

    SID

    The SID of the destination Oracle database. For more information, see the Obtain the SID of an Oracle database section of the "Prepare for physical backup of an Oracle database" topic.

    Database

    The SQL*Plus command that is used to connect to the database. The SQL*Plus command is in the following format: Database username/Password@Instance name as sysdba. Example: sys/password@orcl as sysdba.

    Note

    You can also enter / as sysdba. However, if the operating system authentication is disabled for the sysdba user in your database environment, you cannot connect to the database by using the / as sysdba command. In this case, enter the Database username/Password@Instance name as sysdba command.

    Oracle Home

    The program directory of the database that you want to back up. For more information, see the Obtain the directory in which an Oracle database is installed section of the "Prepare for physical backup of an Oracle database" topic.

    Note

    This parameter is optional.

    Compliance warranty regarding cross-border data transfers

    Read and agree to the compliance commitment by selecting the check box.

    Backup Destination Information

    Backup Storage Type

    The type of storage that is used to store the backup data. Valid values:

    • DBS Storage (recommended): Backup data is stored in DBS without requiring you to create storage space. You are charged based on the volume of your data that is stored in DBS. For more information about the billing method, see Storage fees.

      To reduce storage costs, we recommend that you use subscription storage plans. For more information, see Use storage plans.

    • OSS For User: You must create a bucket in the Object Storage Service (OSS) console in advance.

    Note

    In this example, DBS Storage (recommended) is selected. If you select OSS For User, you must configure the OSS Bucket Name parameter, and only the Standard storage class is supported.

    Storage Encryption

    The method that is used to encrypt the stored data. Valid values:

    • Encrypted: recommended. DBS uses AES-256 to encrypt the stored data. AES-256 is one of the advanced encryption standard ciphers.

      The server-side encryption feature is used in OSS. When you upload an object to OSS, 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, configure the parameters that are described in the following table. Then, click Next in the lower-right corner of the page.

    Parameter

    Description

    Full-scale Backup Frequency

    The frequency of the backup schedule. Valid values: Periodic Backup and Single Backup.

    Note

    If you select Periodic Backup, you must configure the Full Data Backup Recurrence, Start At, and Real-Time Transaction Log Backup parameters.

    Full Data Backup Recurrence

    The days of the week on which DBS runs the backup schedule. You can select one or more days of a week. Select at least one day of the week.

    Start At

    The start time of the backup. We recommend that you specify a point in time during off-peak hours. Example: 01:00.

    Note

    If a previous full data backup is not finished at the start time of the next backup, DBS skips the next backup.

    Incremental Backup

    Specifies whether to enable incremental backup.

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

    Maximum Concurrent Threads for Full Data Backup

    The maximum number of concurrent threads that are available for a full backup. You can configure this parameter to adjust the backup speed. For example, you can reduce the number of backup threads to minimize impacts on the database.

    Backup network speed limit

    The limit on the network bandwidth. You can set the limit based on your business requirements. Default value: 0, which indicates that the network bandwidth is not limited.

    Note

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

    Transaction Log backup interval

    The interval at which incremental backup is performed. DBS performs incremental backup 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 if you set the Incremental backup parameter to Enable.

    Delete Logs upon Backup Success

    Specifies whether to automatically delete the archived log files that are backed up from a self-managed database. Valid values:

    If you select Enable, you must configure the archive log save days parameter.

    archive log save days

    Specifies that DBS automatically deletes the log files archived before this period from a self-managed database after a successful backup. Default value: 7. If you use the default value of this parameter, DBS automatically deletes the log files archived seven days ago from the database 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 a backup to reduce storage space.

    • Disable: Data is not compressed during a backup.

    Backup set mode

    Only the Sandbox instance mount backup is supported. DBS uses the RMAN tool to perform image copy backup. Backup data is streamed and sent to Object Storage Service (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. After the sandbox feature is enabled, backup data can be mounted within seconds.

    You must install the FUSE protocol on your server to ensure successful backups.

  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 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 preceding 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 state 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 a backup schedule.

What to do next

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