Cloud Backup:FAQ for Database Backup

Database instance issues

• What do I do if instance registration for Database Backup fails?

• What do I do if the database instance status is "Inactivated"?

• What do I do if the database instance status is "DB Offline"?

• Why do multiple database instances appear on the ECS Database Instance tab after I register an instance?

• What do I do if the database status cannot be retrieved after instance registration?

Client issues

• How do I check the client process status, find the log path, and restart the client?

• What do I do if the database client status is "Offline"?

• What do I do if the "Failed to run install script:exit status 4" error occurs when I install the backup client for a local SQL Server?

• What do I do if the backup client fails to install for a local SQL Server?

• What do I do if the Database Backup client fails to install on an ECS instance?

Backup issues

• How do I obtain a free trial for local database backup?

• What are the network requirements for local database backup?

• What is the minimum interval for real-time backup? Can it be configured with an incremental backup?

• How do I change the username and password for a database backup?

• What do I do if a database backup fails?

• What do I do if the time taken for an incremental backup of Oracle data is equal to or greater than the time for a full backup?

• RMAN reports a non-fatal error during an Oracle incremental backup

• What do I do if browsing database details fails when I back up SQL Server 2019?

• What to do if the IP address for a local SQL Server database is incorrect in the Cloud Backup console

• Can I back up an SQL Server database to Alibaba Cloud after I enable Transparent Data Encryption (TDE)?

• What do I do if the client goes offline, cannot be uninstalled, and the anti-ransomware policy fails to be deleted after I deploy the anti-ransomware service for an SQL Server database?

• What do I do if I cannot install or use the Database Backup feature after I transfer an ECS instance from its original Alibaba Cloud account to a new one?

• Are there limits on the supported MySQL database versions and operating systems for backup?

• How do I back up a newly created database in MySQL?

• How do I cancel a database backup?

• Why are there duplicate or unexpectedly timed records in the backup history?

• Why does a backup fail and the backup plan status show "Error"?

• Why is the alert time different from the actual error time?

• Why do I receive a failure alert email or text message, but the backup history shows both a successful and a failed backup record at the same time?

Restore issues

• What is the "View Offline Instances Only" feature?

• What do I do if an SQL Server database restore fails?

• What do I do if a SQL Server recovery fails and the agent log indicates a file initialization error?

• How do I perform a cross-database restore between a local database and an ECS database?

Backup vault issues

• What is a database backup vault?

• How does a database backup vault purge expired backups?

• How do I view the backup data size and backup vault usage, and what is the basis for billing?

What do I do if instance registration for Database Backup fails?

First, confirm whether the Database Backup client is installed on the server (local server or ECS instance). If it is, see Uninstall the client to uninstall the client and clear its configuration files. Then, try to register the instance again.

What do I do if the database instance status is "Inactivated"?

What do I do if the database instance status is "Database Offline"?

Why do multiple database instances appear on the ECS Database Instance tab after I register an instance?

If multiple database instances are deployed on an ECS instance, the Cloud Backup console scans and displays all of them during registration.

What do I do if the database status cannot be obtained after instance registration?

• Symptom

  After you register a database instance, the Cloud Backup console cannot retrieve the database status.

• Cause

  The operating system is not supported by the database.

• Solution

  Switch to a supported operating system and try again.

How to check the client process status, find the log path, and restart the client

• Linux

  1. Check the process status of the backup client.

     Run the systemctl status dbackup3-agent or service dbackup3-agent status command to check the process status of the Database Backup client.

     A status of active or dbackup3-agent is running... indicates that the client is running properly.

     ● dbackup3-agent.service - dbackup3 agent daemon
        Loaded: loaded (/usr/lib/systemd/system/dbackup3-agent.service; enabled; vendor preset: disabled)
        Active: active (running) since Mon 2023-12-11 13:47:34 CST; 1min 13s ago
      Main PID: 22192 (dbackup3-agent)
        CGroup: /system.slice/dbackup3-agent.service
                └─22192 /opt/scutech/dbackup3/bin/dbackup3-agent -f /etc/opt/scutech/dbackup3/agent/svc.conf.d
     
     Dec 11 13:47:34 iZbp1******gktZ systemd[1]: Started dbackup3 agent daemon.

  2. Restart the backup client.

     Run the systemctl restart dbackup3-agent or service dbackup3-agent restart command to restart the client process. The client status returns to normal when the Client Status for the database in the console is Installed.

     

  The client log path is: /var/log/dbackup3/agent.log

• Windows

  1. Press Win + R to open the Run dialog box.

  2. Enter services.msc and press Enter to open the Services interface.

  3. In the services list, find the dbackup3-agent service.

  4. Check whether the service status is "Running". If it is not, right-click the dbackup3-agent service and select "Restart" to start it.

  The client log path is: C:\ProgramData\scutech\dbackup3\agent\log\dbackup3-agent.log

What do I do if the database client status is "Offline"?

• Symptom

  The Client Status of the database is Offline.

  

• Cause

  The "Offline" status indicates that Cloud Backup has not received a heartbeat signal from the client process. This can happen for several reasons, such as the client being automatically stopped because of an out of memory error, or the device where the client is located being shut down.

• Solution

  Follow the instructions in How to view the client process status, log path, and restart the client to check and restart the client. After the client status changes to Running, wait for the database Client Status in the console to be displayed as Installed. This indicates that the client has returned to normal.

What do I do if the "Failed to run install script:exit status 4" error occurs when I install the backup client for a local SQL Server?

This error occurs because the local security policy setting "Admin Approval Mode for the Built-in Administrator account" is not enabled. This policy must be set to Enabled.

1. Press Win+R to open the Run dialog box, enter gpedit.msc, and then run the Local Group Policy Editor.

2. In the Local Group Policy Editor pane, navigate to Computer Configuration > Windows Settings > Security Settings > Local Policies > Security Options. In the right-side pane, find User Account Control: Admin Approval Mode for the Built-in Administrator account and change its status to Enabled.

What do I do if the backup client fails to install for a local SQL Server?

1. Log on to the server and view the backup log.

   Windows client log path: C:\ProgramData\scutech\dbackup3\agent\log\dbackup3-agent.log

2. In the log, check the entries around the time the task failed.

   If the backup log contains the error message Failed to install dbackup3-agent service, errno=1783, The stub received bad data, the system may have rejected the installation. Check whether any antivirus or security software has blocked the installation and review the block records. Add the installation program to the whitelist or temporarily disable the security software before you try to install it again.

What do I do if the Database Backup client fails to install on an ECS instance?

Check the following two items to ensure that the client can be installed successfully:

1. Cloud Assistant status: Confirm that Cloud Assistant is installed correctly and is running.

   If the installation fails, find a failed command record in the Cloud Assistant console. Copy the command and run it manually on the ECS host. During manual installation, if network connectivity issues or system script execution errors occur, specific error messages appear on the screen. Use these messages to resolve the issues, for example, by adjusting network settings.

   After you resolve all issues and the script runs successfully, the client is installed. Then, trigger the installation again in the console to complete the process.

2. C drive space: Ensure that there is enough free space on the C drive. Insufficient space can prevent the client from being installed.

How can I get a free trial for local database backup?

The free trial for local database backup is the same as the free trial for ECS database backup. For more information about the free trial, see 30-day Free Trial.

What are the network requirements for local database backup?

The local database server must be connected to the Alibaba Cloud virtual private cloud (VPC) through a leased line or VPN. The routing must be configured from on-premises to the cloud at 100.64.0.0/10 or 100.64.0.0/11, 100.96.0.0/11.

What is the minimum interval for real-time backup? Can it be configured with incremental backup?

Real-time backup can theoretically achieve a recovery point objective (RPO) of seconds and currently supports MySQL and Oracle databases. After you enable real-time backup, you cannot configure a separate traditional log backup. However, you can still use it with an incremental backup to further enhance your data protection policy.

How do I change the username and password for a database backup?

During the backup process, use Reactivate to change the username and password for your backups, for example, if a password expires. Reactivation does not affect existing backup plans. However, it does affect backup jobs that are in progress. We recommend the following:

1. On the Backup Plans tab, pause any real-time log backups.

2. In the Actions column for the database, choose More > Reactivate.

What do I do if a database backup fails?

What do I do if the time taken for an incremental backup of Oracle data is equal to or greater than the time for a full backup?

• Symptom

  The time that is taken for an incremental backup and a log backup is close to or even exceeds the time for a full backup.

• Solution

  Enable Block Change Tracking (BCT) in the Oracle database. BCT is a feature that is used to speed up RMAN incremental backups by tracking changes to data blocks. This reduces backup time. This setting is disabled by default. You must manually enable it to take advantage of its ability to accelerate RMAN incremental backups.

  Pros and cons of BCT

  Pros

  Cons

  Accelerates RMAN incremental backups The BCT file records data block modifications. During an RMAN incremental backup, RMAN does not need to scan the entire database. It only needs to locate changed blocks through the BCT file. For large databases, this can reduce incremental backup time by over 90%. For example, a full table scan of a 1 TB database might take 1 hour, while BCT can complete an incremental backup in a few minutes. Reduces I/O load Reduces physical reads. During the backup process, the BCT file is read directly, avoiding a full table scan and reducing the impact of the backup on the production environment. Low resource consumption Almost no extra memory overhead. The BCT file typically requires only a few hundred MB (for example, the BCT file for a 1 TB database is about 100 MB to 200 MB). Compatibility Supports all Oracle versions (starting from 10g R2). In Oracle 12c and later, it supports redundant configurations (multiple BCT file replicas for improved fault tolerance).

  Additional disk space usage File size: Although only a few hundred MB, ensure the storage path has enough space. Redundant configuration: If you configure multiple replicas (such as REDUNDANCY 2), the disk usage will double. Minor performance impact Write operation overhead: Each time a data block is modified, the BCT file needs to be updated, which may have a slight performance impact on systems with high write loads. Test scenario: In an online transactional processing (OLTP) system with tens of thousands of transactions per second, the performance impact of BCT is usually negligible. However, monitoring is required in extreme high-concurrency scenarios. Risk of file corruption Single point of failure: If the BCT file is corrupted and no redundancy is configured, incremental backups may fail. Repair complexity: You need to re-enable BCT and rebuild the file, which may require a short downtime.

  Scenarios where we recommend that you enable BCT:

  • Frequent incremental backups: systems that perform daily or hourly RMAN incremental backups.

  • Large databases: optimization of incremental backup time for terabyte-scale databases.

  • High availability requirements: production environments that require fast recovery and rely on incremental backups.

  Scenarios where you should enable BCT with caution:

  • Very small databases: for databases smaller than 1 GB, the benefits of BCT may not be significant.

  • Extreme high-write loads: for OLTP systems with tens of thousands of transactions per second, the performance impact needs to be considered.

  • Limited storage space: if disk space is limited, the storage requirements of the BCT file need to be evaluated.

RMAN reports a non-fatal error during an Oracle incremental backup

• Symptom

  Oracle full backups are successful, but incremental backups consistently fail. The following error message is reported:

  oracle.phxxdb.18472|RMAN reports a non-fatal error:
  ORA-19505: failed to identify file "/arch/1_5137021_976544044.dbf"
  ORA-27037: unable to obtain file status
  Linux-x86_64 Error: 2: No such file or directory
  Additional information: 3

• Cause

  The required archived logs cannot be found. This issue can occur if another script or backup job moves the archived logs. If other backup scripts or software run concurrently with Cloud Backup, these external processes can change the location of the archived logs. This causes the Cloud Backup incremental backup to fail because it cannot find the necessary files.

• Solution

  Do not use Cloud Backup concurrently with other backup software or scripts. This can cause backups to fail or become unrecoverable.

What do I do if browsing database details fails when I back up SQL Server 2019?

• Symptom

  When you create or edit a backup plan for SQL Server 2019 and select a database instance, the console displays the error message: "Failed to list unibackup instance detail".

• Cause

  When you back up SQL Server 2019, if other backup software or scripts are performing backup operations at the same time, browsing database details may fail when you create or edit a backup plan and select a database instance.

• Solution

  1. In the SQL Server database, query the number of databases and backup sets.

     select count(database_id) from master.sys.databases
     select count(backup_set_id) from msdb.dbo.backupset

  2. Delete the backup records in msdb.dbo.backupset.

     Important

     Deleting backup records affects you. If you have your own backups, the backup records are purged, and you cannot restore these records through the normal process. However, this does not affect your data backups because the next backup is automatically converted to a full backup. Note that when you back up SQL Server 2019, you cannot use it with other backup software or scripts at the same time.

     use msdb;
     exec sp_delete_backuphistory @oldest_date = '04/10/2024' ---Retain records from 4/10 onwards, delete all before 4/9. You need to confirm the retention period.

What to do if the IP address for a local SQL Server database is incorrect in the Cloud Backup console

• Symptom

  After you register a local SQL Server database with Cloud Backup, the IP address displayed in the Cloud Backup console does not match the IP address of the local machine. This issue can occur even if the local client status is Normal and the IP address of the local machine has not been changed.

• Cause

  This issue occurs in an environment with multiple network interface cards because Cloud Backup retrieves the IP address from an unused network interface card.

• Solution

  Disable the unused network interface card and then reinstall the client.

Can I back up an SQL Server database to Alibaba Cloud after enabling Transparent Data Encryption (TDE)?

No.

What do I do if the client goes offline, cannot be uninstalled, and the anti-ransomware policy fails to be deleted after deploying the anti-ransomware service for an SQL Server database?

• Symptom

  After you deploy the anti-ransomware service for an SQL Server database, the client is offline, the anti-ransomware policy cannot be deleted, and the client cannot be uninstalled.

  At this point, the dbackup3-agent service in Windows Task Manager is stopped, and the agent log contains entries similar to "Stopping all jobs".

  

• Cause

  The client is blocked by antivirus software. Check the antivirus software for any related block records at the corresponding time.

• Solution

  Add the client to the trusted list in the antivirus software, and then restart the client service or reinstall the client.

What do I do if I cannot install or use the Database Backup feature after transferring an ECS instance from its original Alibaba Cloud account to a new one?

When you transfer an ECS instance from its original Alibaba Cloud account to a new one, the ECS metadata is not automatically synchronized to the Cloud Backup service. You must first complete the synchronization in the Cloud Backup service backend before installing and use the feature. For specific steps, contact "Cloud Backup Support" or join the "Cloud Backup Online Support" DingTalk group for assistance.

• Cloud Backup Technical Support Group

  Obtain quick answers to questions about costs, features, and usage. Search for the public DingTalk group and join. The DingTalk group number is 88650005148.

• Cloud Backup Expert Support

  Technical experts provide on-site analysis to quickly resolve product issues. Click to contact Cloud Backup support. We recommend that you use Chrome. Add the DingTalk contact. The DingTalk ID is d37_g935gslgo.

Are there limits on the supported MySQL database versions and operating systems for backup?

Yes, there are. Limits apply to the supported database versions, operating systems, and backup features. For example, MySQL databases that are deployed in Windows are not supported. For more information, see Compatibility list and limits.

How do I back up a newly created database in MySQL?

MySQL backups are performed at the database instance level. You do not need to manually configure backups for new databases. The next backup automatically includes the new database.

How do I cancel a database backup?

Why are there duplicate or unexpectedly timed records in the backup history?

This issue usually occurs when the server (local server or ECS instance) on which the Database Backup client is installed is cloned, or when a new ECS instance or local server is created from an image that contains the same backup client. Because the cloned server retains some of the client information from the original server, duplicate backup records may be generated. To resolve this issue, log on to the cloned server and uninstall the client. For more information about how to uninstall the backup client, see the following steps:

Why does a backup fail and the backup plan status show "Error"?

If a backup plan status is "Error" and the backup fails, first check whether the server (local server or ECS instance) where the client is installed has been cloned, had its operating system reinstalled, or had its system disk reset. These operations can invalidate the association between the backup plan and the client. To resolve this issue, follow these steps:

1. Make sure that you have uninstalled the client and its configuration files from the cloned server. For more information, see Uninstall the client.

2. Make sure that the client status on the current server is "Installed".

   

3. After you complete the preceding steps, delete the original backup plan from the console and create a new one.

Why is the alert time different from the actual error time?

Text message alerts have a nighttime suppression feature that delays alerts that are triggered between 8:00 PM and 8:00 AM the next day until after 8:00 AM. Email alerts are not affected by this feature and are sent immediately.

Why do I receive a failure alert email or text message, but the backup history shows both a successful and a failed backup record at the same time?

This issue usually occurs when the server (local server or ECS instance) on which the Database Backup client is installed is cloned, or when a new ECS instance or local server is created from an image that contains the same backup client. Because the cloned server retains some of the client information from the original server, duplicate backup records may be generated. To resolve this issue, log on to the cloned server and uninstall the client. For more information about how to uninstall the backup client, see the following steps:

Description of the "View Offline Instances Only" feature

The View Offline Instances Only feature is useful in scenarios where a client can no longer connect to its original instance server or restore backup data. This can happen if the operating system of the client machine is reinstalled, or if the client process and configuration are deleted by malicious software. If you install a new client in this situation, the system assigns a new instance ID to distinguish the new client from the offline one and prevent confusion. Then restore data from the offline instance to the new client instance. For more information about the restore steps, see Restore MySQL, Restore Oracle, and Restore SQL Server.

What do I do if an SQL Server database restore fails?

1. Log on to the server and view the backup log.

   Windows client log path: C:\ProgramData\scutech\dbackup3\agent\log\dbackup3-agent.log

2. In the log, check the entries around the time the task failed.

   If the backup log contains the keyword RestoreContainer::ValidateTargetForCreation, it indicates that when you restored a database with the same name, you changed only the path but not the database name. This caused a name conflict and the restore operation failed. To successfully restore the database, you must change both the database name and the path.

What do I do if a SQL Server recovery fails and the agent log indicates a file initialization error?

• Symptom

  When a SQL Server recovery fails, the agent log indicates that a file failed to initialize. The log contains the following details:

  2025-11-10 11:25:53.967@iZrxhug********@2208@LM_INFO@dbackup3-agent|[SQLSERVER] output: 100 percent processed.
  2025-11-10 11:25:53.968@iZrxhug********@2208@LM_INFO@dbackup3-agent|[SQLSERVER] output: Processed 51595000 pages for database 'xxx', file 'xxx' on file 1.
  2025-11-10 11:25:53.985@iZrxhug********@2208@LM_INFO@dbackup3-agent|[SQLSERVER] output: Processed 3865 pages for database 'xxx', file 'xxx_log' on file 1.
  2025-11-10 11:25:53.987@iZrxhug********@2208@LM_INFO@dbackup3-agent|[SQLSERVER] output: File "xxx_log" failed to initialize correctly. See the error log for details.
  2025-11-10 11:25:53.989@iZrxhug********@2208@LM_INFO@dbackup3-agent|[SQLSERVER] output: RESTORE DATABASE is terminating abnormally.

  Additionally, the SQL Server error log reports the message the file "xxx_log" failed to initialize correctly.

  

• Cause

  If a source database on SQL Server 2008 R2 was previously encrypted, disabling encryption can leave residual information. When you back up this database and restore the backup set to another instance, an initialization error occurs. The analysis process is as follows:

  Note

  If the source database is SQL Server 2008 R2 and has transparent data encryption (TDE) enabled, the recovery operation fails even if the target instance is a later version, such as SQL Server 2014. The error message "Certificate not found" is returned. To complete the recovery, you must manually restore the certificate and private key.

  1. Confirm the database version from the SQL Server error log.

     

  2. This issue is likely related to TDE. Confirm whether TDE is enabled on the source database. Also, check if operations such as disabling encryption were recently performed.

     Execute the following SQL statement on the source database. If the key_algorithm and key_length fields in the query result are not NULL, the database was likely encrypted in the past.

     USE master;
     SELECT 
         d.name,
         d.is_encrypted,
         drs.database_id,
         drs.encryption_state,
         drs.percent_complete,
         drs.key_algorithm,
         drs.key_length
     FROM sys.databases AS d
     LEFT JOIN sys.dm_database_encryption_keys AS drs
         ON d.database_id = drs.database_id;

     The following figure shows a sample query result.

     

• Solution

  • Upgrade the source database to a later version and create a new backup. Use the new backup set to perform the recovery. Previous backup sets are invalid.

  • Restore the private key and certificate from the source instance to the target instance, and then perform the recovery operation.

    After the recovery is complete, delete the TDE encryption certificate and database encryption key from the target instance. Then, back up the target instance. Subsequent backup and recovery operations on the target instance will function correctly.

    Note

    Even if the data backup was created after TDE was disabled, the recovery process still requires the private key and certificate. These are required to process the residual encrypted metadata in the backup. However, the restored database is not encrypted. You can then use the database normally without the certificate.

    # Perform the following operations on the source instance
    USE master;
    
    # 1. Query the certificate name for the TDE-encrypted database
    SELECT d.name AS DatabaseName,
           k.encryption_state,
           c.name AS CertificateName
    FROM sys.dm_database_encryption_keys AS k
    JOIN sys.certificates AS c
        ON k.encryptor_thumbprint = c.thumbprint
    JOIN sys.databases AS d
        ON k.database_id = d.database_id
    
    # Assume the CertificateName in the result is TDECert. Back up the TDE certificate and private key to a custom path.
    BACKUP CERTIFICATE TDECert
       TO FILE = 'C:\Backup\TDECert.cer'  -- Specify a custom file path
       WITH PRIVATE KEY (
            FILE = 'C:\Backup\TDECert_PrivateKey.pvk',    -- Specify a custom file path
            ENCRYPTION BY PASSWORD = 'Strong_Password_123!'    -- Remember this password
       );
    
    -- Copy the certificate and private key from the path above to the target instance
    
    # 2. Perform the following operations on the target instance
    USE master;
    
    # Restore the master key. If the message 'The master key already exists in the database. Drop the master key before you perform this statement.' is returned, skip this step.
    CREATE MASTER KEY ENCRYPTION BY PASSWORD = 'Another_Strong_Password_456!';
    
    # Restore the TDE certificate
    CREATE CERTIFICATE TDECert -- Specify a custom certificate name. You will use it later for deletion.
        FROM FILE = 'C:\TDE_Test\TDECert.cer' -- The path where the copied files are located
        WITH PRIVATE KEY (
            FILE = 'C:\TDE_Test\TDECert_PrivateKey.pvk',
            DECRYPTION BY PASSWORD = 'Strong_Password_123!'  -- The password used to back up the private key
        );
    
    
    # 3. Perform the recovery steps in the Cloud Backup console as usual
    
    
    # 4. After recovery, delete the database encryption key
    USE TDE_TestDB_Restore -- The name of the target database
    DROP DATABASE ENCRYPTION KEY;
    
    # 5. Delete the certificate
    USE master;
    DROP CERTIFICATE TDECert;

How do I perform a cross-database restore between a local database and an ECS database?

Direct mutual restoration is not supported. Register the database on the ECS instance as a local database instance. After registration, restore data between different local database instances.

What is a database backup vault?

You must create a database backup vault before you create a database backup plan.

A database backup vault is a storage vault that stores your database backup data. The cost of a database backup is determined by the vault rental fee and the vault capacity. For more information, see Billing methods and billable items.

How does a database backup vault purge expired data?

Incremental backups, cumulative incremental backups, and log backups depend on a complete preceding backup chain. The backup chain includes the preceding full backup and any incremental, cumulative incremental, or log backups. In a backup chain that includes a full backup and incremental, cumulative incremental, and log backups, all backups on which the complete backup chain depends are retained in the backup vault and occupy backup space until the last backup in the chain expires. You must configure the backup cycle and expiration time in a reasonable manner.

For example, you perform a full backup on September 1 and an incremental backup every day from September 2 to September 7. The retention period is 7 days. The seven backups from September 1 to September 7 are automatically deleted after all data expires on September 14.

How do I view the backup data size and backup vault usage? What is the billing basis?

Source Data Size is the total amount of data that has been backed up. For example, if you back up a 1 TB file twice, the source data size is 2 TB. Cloud BackupCloud Backup uses deduplication and compression to reduce backup vault usage and lower your costs. Billing is based on the actual Storage Vault Data Size. View the Source Data Size and Storage Vault Data Size of a database backup vault on the Vault Management page.