FAQ and solutions for Database Backup in Cloud Backup - Cloud Backup

This topic describes common issues and solutions for Cloud Backup when you use the Database Backup feature.

List of questions

Database instance issues

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

First, you can 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, you can try to register the instance again.

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

MySQL

The Database Account or Password entered during registration is incorrect, or the user account has insufficient permissions. Verify that the username and password are correct, and grant sufficient permissions to the backup account. Alternatively, create a dedicated user for backups and try again.
For more information, see Create a MySQL backup account and configure permissions.
You can run the systemctl restart dbackup3-agent command to restart the backup client.
If the instance is still inactive after you restart the backup client, you can collect the relevant logs for further analysis.
The client log path is /var/log/dbackup3/agent.log.

Oracle

The Database Account or Password entered during registration is incorrect, or the user account has insufficient permissions. Confirm that the username and password are correct and that the backup account has sufficient permissions. You can also create a dedicated user for backups and try again.
For more information, see Create an Oracle backup account and configure permissions.
You can restart the backup client.
- Linux: You can run the systemctl restart dbackup3-agent command to restart the backup client.
- Windows:
  1. You can press Win + R to open the Run dialog box.
  2. You can enter services.msc and press Enter to open the Services interface.
  3. In the services list, you can find the dbackup3-agent service.
  4. You can check whether the service status is "Running". If it is not, you can right-click the dbackup3-agent service and select "Restart" to start it.
If the instance is still inactive after you restart the backup client, you can collect the relevant logs for further analysis.
- The client log path on Linux is /var/log/dbackup3/agent.log.
- The client log path on Windows is Local Disk (C) > ProgramData > scutech > dbackup3 > agent > log > dbackup3-agent.log.

SQL Server

The Database Account or Password is incorrect, or the user account has insufficient permissions. To resolve this issue, verify that the username and password are correct and grant sufficient permissions to the backup account. As a best practice, create a dedicated user for backups and try the operation again.
For more information, see Create an SQL Server backup account and configure permissions.
You can restart the dbackup3-agent service.
1. You can press Win + R to open the Run dialog box.
2. You can enter services.msc and press Enter to open the Services interface.
3. In the services list, you can find the dbackup3-agent service.
4. You can check whether the service status is "Running". If it is not, you can right-click the dbackup3-agent service and select "Restart" to start it.
If the instance is still inactive after you restart the service, you can collect the relevant logs for further analysis.
The client log path is Local Disk (C) > ProgramData > scutech > dbackup3 > agent > log > dbackup3-agent.log.

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

MySQL

You can query the MySQL database status.
You can log on to the ECS instance and run the systemctl status mysqld command to query the MySQL database status. If the process status is inactive, the MySQL database service is not started.
You can restart the MySQL service.
After you run the systemctl start mysqld command to restart the MySQL service, the Database Status in the console changes to Online.

Oracle

You can query the Oracle database listener status.
You can log on to the ECS instance and run the following commands:
```
su - oracle
lsnrctl status
```
If the service is started, its status is running. If the service is not started, the message TNS: no listener appears.
You can query the Oracle database running status.
```
su - oracle
sqlplus /nolog
conn /as sysdba
SELECT name, status FROM v$instance;
```
The v$instance view provides information about the database instance. The status column shows the instance status. If the status is OPEN, the database is open and can accept connections.
You can restart the Oracle listener.
You can start the Oracle listener service to listen for connection requests from clients.
```
su - oracle
lsnrctl start
```
You can restart the Oracle database instance.
In SQL*Plus, you can log on as a system administrator and start the Oracle instance.
```
sqlplus / as sysdba;
STARTUP;
```
After startup, the Database Status in the console is Online.

SQL Server

You can query the SQL Server database status.
1. You can press Win + R to open the Run dialog box.
2. You can enter services.msc and press Enter to open the Services interface.
3. In the services list, you can find the SQL Server service. For example, "SQL Server (MSSQLSERVER)".
4. You can check the service status. The status can be "Running", "Stopped", or "Paused".
You can restart the SQL Server service.
If the SQL Server database status is Stopped or Paused, right-click the SQL Server service and select Start. If the Start option is dimmed, reopen Windows Services Manager as an administrator and try again. After the service starts, the Database Status on the console is Online.

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
You can switch to a supported operating system and try again.

Client issues

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

Linux
1. You can check the process status of the backup client.
  You can 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. You can restart the backup client.
  You can 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. You can press Win + R to open the Run dialog box.
2. You can enter services.msc and press Enter to open the Services interface.
3. In the services list, you can find the dbackup3-agent service.
4. You can check whether the service status is "Running". If it is not, you can 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.

You can press Win+R to open the Run dialog box, enter gpedit.msc, and then run the Local Group Policy Editor.
In the Local Group Policy Editor pane, you can navigate to Computer Configuration > Windows Settings > Security Settings > Local Policies > Security Options. In the right-side pane, you can 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?

You can log on to the server and view the backup log.
Windows client log path: C:\ProgramData\scutech\dbackup3\agent\log\dbackup3-agent.log
In the log, you can 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. You can check whether any antivirus or security software has blocked the installation and review the block records. You can 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?

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

Cloud Assistant status: You can confirm that Cloud Assistant is installed correctly and is running.
If the installation fails, you can usually find a failed command record in the Cloud Assistant console. You can 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. You can 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, you can trigger the installation again in the console to complete the process.
C drive space: You can ensure that there is enough free space on the C drive. Insufficient space can prevent the client from being installed.

Backup issues

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, you can 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:

On the Backup Plans tab, you can pause any real-time log backups.
In the Actions column for the database, choose More > Reactivate.

What do I do if a database backup fails?

MySQL database backup fails

In the Job History, the job status is Error.

You can follow these steps:

You can log on to the ECS instance or local server and check the MySQL service status.
You can use the command systemctl status mysqld. A normal service status is "active". A status of "inactive" is abnormal. If the status is "inactive", you can restart the service and try again.
You can confirm that the database username, password, and permissions are configured correctly. This issue can also be caused by an expired password or insufficient permissions after a user's permissions are changed.
If the Database Account or Password entered during registration is incorrect, or if the user account has insufficient permissions, ensure that the username and password are correct and grant the required permissions to the backup account. We recommend creating a dedicated user for backups.
The minimum required permissions are RELOAD, LOCK TABLES, REPLICATION, and PROCESS.
You can log on to the server and view the backup log.
Linux client log path: /var/log/dbackup3/agent.log
- If the keyword uploadPart SecurityTokenExpired appears, the local time is incorrect. You can correct the local time.
- If the keyword ib_logfile0 appears, a restore operation was performed while another restore job was not yet complete. This caused ib_logfile0 to be deleted but not recreated, which leads to subsequent backup failures.
- If the message Error: failed to execute query LOCK TABLES FOR BACKUP: Access denied; you need (at least one of) the RELOAD privilege(s) for this operation appears, the account that is used for the backup has insufficient permissions. To perform a backup job, the account needs at least the following permissions: RELOAD, LOCK TABLES, REPLICATION, and PROCESS. In MySQL 8.0, the BACKUP_ADMIN permission is also required.
- If the message no space left on device appears, a restore job fails for MySQL backup client version 29292 because of insufficient disk space. Incremental backup files need to be restored to the cache. You can create a symbolic link to point the storage path to another disk to resolve the space shortage.
- If the log backup status in the console is "Error" and the log contains the keyword @LM_ERROR@agent|To backup binlog in slave node needs to set log_slave_updates to ON, the backup node is a slave node. To perform log backups correctly, you can set the configuration item log_slave_updates=1 to enable this setting. After you change this configuration, you must perform a full backup before you perform a log backup.

Oracle database backup fails

You can log on to the server and view the backup log.
Linux client log path: /var/log/dbackup3/agent.log
Windows client log path: C:\ProgramData\scutech\dbackup3\agent\log\dbackup3-agent.log
In the log, you can check the entries around the time the task failed. If the backup log contains any of the following error messages, you can use the corresponding solution:
- If the keyword ORA-12560: TNS:protocol adapter error appears, you can check whether the ORACLE_SID environment variable is not set or is set incorrectly. An incorrect setting prevents a connection to Oracle. You can try to log on using the sqlplus command with sysdba permissions. If you can log on successfully after you correctly configure the ORACLE_SID environment variable, the issue is resolved.
- If the keyword sbtclose2 returned error-failed to close file appears, the local time differs significantly from the server time, or the system time zone is set incorrectly. You can change the time on the database server and restart the dbackup3-agent service. For more information about how to restart the service, see How do I check the client process status, find the log path, and restart the client?.
- If the keyword Failed to probe oracle instances appears, there are two possible causes:
  - The Oracle instance was not started when the client was installed.
    You can restart the dbackup3-agent service. For more information about how to restart the service, see How do I check the client process status, find the log path, and restart the client?.
  - The ORACLE_HOME environment variable is not configured correctly.
    1. For Linux: You can run /etc/init.d/dbackup3-agent config oracle and enter the actual $ORACLE_HOME path.
    2. You can restart the dbackup3-agent service. For more information about how to restart the service, see How do I check the client process status, find the log path, and restart the client?.
- If the keyword ORA-12154: TNS:could not resolve the connect identifier specified appears, your password contains special characters that cause validation to fail. This results in a backup failure.
- If the keyword ORA-01017: invalid username/password; logon denied appears, you can reactivate the instance with the correct username and password and then perform the backup again.
- If the keyword The difference between the request time and the current time is too large appears, the time on the server where the Cloud Backup client is installed does not match the time on the Cloud Backup server.
  Solution:
  1. Check and sync the time: To ensure that the server time is synchronized with Coordinated Universal Time (UTC), you can use the Network Time Protocol (NTP) service for automatic synchronization. On Linux, you can use the ntpdate or chrony command to sync the time. You can run the sudo ntpdate pool.ntp.org command for manual synchronization.
  2. Check the time zone settings: To ensure that the time zone is set correctly, you can use the timedatectl command to view and set the time zone.
  3. You can restart the backup client and then run the backup operation again in the Cloud Backup console. For more information about how to restart the client, see How do I check the client process status, find the log path, and restart the client?.

SQL Server database backup fails

If a backup fails when you use Cloud Backup to back up an SQL Server, you can follow these steps:

You can log on to the server and view the backup log.
The Windows client log path is: C:\ProgramData\scutech\dbackup3\agent\log\dbackup3-agent.log
In the log, you can find and analyze the entries around the time the task failed based on the time range (start time and end time) from the error record in the console. If the backup log contains any of the following error messages, you can use the corresponding solution:
- Error: The login has insufficient permissions.
  Analysis: The SQL Server backup user has insufficient permissions.
  Solution: You can check the backup account and its permissions. For more information, see Step 2: Create a backup account and configure permissions.
- Error: Login failed for user 'xxx'.
  Analysis: The password for the SQL Server backup user has expired (Error Code: 18487, SQL State: 28000).
  Solution: Change the backup user's password in SQL Server. Then, log on to the Cloud Backup console and in the Actions column for the database, choose More > Reactivate.
- Error: Cannot overwrite file.
  Analysis: The SQL Server database restore path is occupied by another database.
  Solution: You can create a new restore job. When you restore from a specified backup, you can double-click to modify the restore path.
- Error: The target SQL Server database does not exist. Make sure you have entered the name correctly.
  Analysis: The target SQL Server database does not exist.
  Solution: You can confirm that the target database exists. If the database no longer exists, you can edit the backup plan and remove the corresponding database.
- Error: The database is participating in a database mirroring session or an availability group. Some operations are not allowed on a database that is participating in a database mirroring session or an availability group.
  Analysis: SQL Server AlwaysOn is enabled for the SQL Server database.
  Solution: The target instance is not attached to an AlwaysOn cluster. You can select the corresponding cluster.
- Error: The database is configured for database mirroring or is joined to an availability group. If you want to restore the database, use ALTER DATABASE to remove mirroring or remove the database from its availability group.
  Analysis: SQL Server AlwaysOn is enabled for the SQL Server database.
  Solution: The target instance is not attached to an AlwaysOn cluster. You can select the corresponding cluster.
- Error:
  The backup job fails in the console with the message "Job failed, error: -1 Backup or restore of database ""xxx"" failed, VDI error "0x80770004"".
  Troubleshooting steps:
  1. You can go to the C:\ProgramData\scutech\dbackup3\agent\log\dbackup3-agent.log directory and open the log file. You can locate the logs around the time the task failed based on the time range (start time and end time) from the error record in the console.
  2. If the log contains "Failed to receive WebSocket data from x.x.x.x:60305, errno=10054, connection reset" or "Failed to open socket x.x.x.x:60305, errno=10060, connection timed out", the connection between the client and the backup server was interrupted. You can check the network connectivity.
  3. When "Channel xxxxxxxxxxxxxx is registered" appears in subsequent logs, the client has reconnected to the server after it retries. At this point, you can trigger a new backup job or wait for the next scheduled job to run and check whether the backup proceeds normally.
  4. If the backup still fails or other errors occur, you can join the internal support group or contact a service expert for further technical support. You can send logs using DingTalk.
    - Cloud Backup Technical Support Group
      You can obtain quick answers to questions about costs, features, and usage. Click to join the Cloud Backup online support group. We recommend that you use Chrome. You can search for the public 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. You can add the DingTalk contact. The DingTalk ID is d37_g935gslgo.

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:

You can 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.

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, you can 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. You can 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.
```

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

No, you cannot.

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. You can check the antivirus software for any related block records at the corresponding time.
Solution
You can 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 you can install and use the feature. For specific steps, you can contact "Cloud Backup Support" or join the "Cloud Backup Online Support" DingTalk group for assistance.

Cloud Backup Technical Support Group
You can obtain quick answers to questions about costs, features, and usage. Click to join the Cloud Backup online support group. We recommend that you use Chrome. You can search for the public 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. You can 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?

Cancel a MySQL database backup

After you completely and correctly cancel a database backup, no extra fees are incurred and no resources are occupied.

Important

When you cancel a database backup, your backup data is deleted and cannot be recovered. You must evaluate the impact before you proceed.

You can delete the backup plan.
You can unregister the instance. When you unregister an ECS instance database, the installed backup client is automatically uninstalled.

If the MySQL database is installed on a local server, you can log on to the local service and uninstall the client.

Linux:

CentOS

sudo rpm --erase "dbackup3-agent-mysql"
sudo rpm --erase "dbackup3-agent"
sudo rpm --erase "dbackup3-common"

Ubuntu

sudo dpkg -r "dbackup3-agent-mysql" "dbackup3-agent" "dbackup3-common"

You can delete the following directories:

Linux:

/etc/default/dbackup3*
/opt/scutech
/var/opt/scutech/
/var/log/dbackup3/
/etc/opt/scutech/

You can delete the backup vault.
In the navigation pane on the left, choose Vault Management, and then find and delete the backup vault.

Cancel an Oracle database backup

After you completely and correctly cancel a database backup, no extra fees are incurred and no resources are occupied.

Important

When you cancel a database backup, your backup data is deleted and cannot be recovered. You must evaluate the impact before you proceed.

You can delete the backup plan.
You can unregister the instance. When you unregister an ECS instance database, the installed backup client is automatically uninstalled.
If the Oracle database is installed on a local server, you can log on to the local service and uninstall the client.
- Windows:
  1. You can go to the backup client installation directory (PowerShell). For example, C:\Program Files\aliyun\unibackup>.
  2. You can run the command.
```
 .\uninstall-unibackup.exe /S /NCRC
```
- Linux:
  - CentOS
```
sudo rpm --erase "dbackup3-agent-oracle"
sudo rpm --erase "dbackup3-agent"
sudo rpm --erase "dbackup3-common"
```
  - Ubuntu
```
sudo dpkg -r "dbackup3-agent-oracle" "dbackup3-agent" "dbackup3-common"
```
You can clear the configuration files.
- Windows:
  You can delete all configuration files under c:\programdata\scutech.
- Linux:
  You can delete the following directories:
```
/etc/default/dbackup3*
/opt/scutech
/var/opt/scutech/
/var/log/dbackup3/
/etc/opt/scutech/
```
You can delete the backup vault.
In the navigation pane on the left, click Vault Management, locate the target backup vault, and delete it.

Cancel an SQL Server database backup

After you completely and correctly cancel a database backup, no extra fees are incurred and no resources are occupied.

Important

When you cancel a database backup, your backup data is deleted and cannot be recovered. You must evaluate the impact before you proceed.

You can delete the backup plan.
You can unregister the instance. When you unregister an ECS instance database, the installed backup client is automatically uninstalled.
If the SQL Server database is installed on a local server, you can log on to the local service and uninstall the client.
- Windows:
  1. You can go to the backup client installation directory (PowerShell). For example, C:\Program Files\aliyun\unibackup>.
  2. You can run the uninstall-unibackup.exe command and follow the wizard to complete the uninstallation.
You can delete all configuration files under c:\programdata\scutech.
You can delete the backup vault.
In the navigation pane on the left, click Vault Management. Find and delete the corresponding backup vault.

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, you can log on to the cloned server and uninstall the client. For more information about how to uninstall the backup client, see the following steps:

Uninstall the MySQL backup client

When you unregister an ECS instance database, the installed backup client is automatically uninstalled. If the MySQL database is installed on a local server, you can uninstall the client as follows:

You can uninstall the client.

Linux:

CentOS

sudo rpm --erase "dbackup3-agent-mysql"
sudo rpm --erase "dbackup3-agent"
sudo rpm --erase "dbackup3-common"

Ubuntu

sudo dpkg -r "dbackup3-agent-mysql" "dbackup3-agent" "dbackup3-common"

You can delete the following directories:

Linux:

/etc/default/dbackup3*
/opt/scutech
/var/opt/scutech/
/var/log/dbackup3/
/etc/opt/scutech/

Uninstall the Oracle backup client

When you unregister an ECS instance database, the installed backup client is automatically uninstalled. If the Oracle database is installed on a local server, you can uninstall the client as follows:

You can uninstall the client.

Windows:
1. You can go to the backup client installation directory (PowerShell). For example, C:\Program Files\aliyun\unibackup>.
2. You can run the command.
```
 .\uninstall-unibackup.exe /S /NCRC
```

Linux:

CentOS

sudo rpm --erase "dbackup3-agent-oracle"
sudo rpm --erase "dbackup3-agent"
sudo rpm --erase "dbackup3-common"

Ubuntu

sudo dpkg -r "dbackup3-agent-oracle" "dbackup3-agent" "dbackup3-common"

You can clear the configuration files.
- Windows:
  You can delete all configuration files under c:\programdata\scutech.
- Linux:
  You can delete the following directories:
```
/etc/default/dbackup3*
/opt/scutech
/var/opt/scutech/
/var/log/dbackup3/
/etc/opt/scutech/
```

Uninstall the SQL Server backup client

When you unregister an ECS instance database, the installed backup client is automatically uninstalled. If the SQL Server database is installed on a local server, you can uninstall the client as follows:

You can uninstall the client.
- Windows:
  1. You can go to the backup client installation directory (PowerShell). For example, C:\Program Files\aliyun\unibackup>.
  2. You can run the uninstall-unibackup.exe command and follow the wizard to complete the uninstallation.
You can clear the configuration files.
- Windows:
  You can delete all configuration files under c:\programdata\scutech.

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

If a backup plan status is "Error" and the backup fails, you can 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, you can follow these steps:

You can make sure that you have uninstalled the client and its configuration files from the cloned server. For more information, see Uninstall the client.
You can make sure that the client status on the current server is "Installed".
After you complete the preceding steps, you can 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?

Uninstall the MySQL backup client

When you unregister an ECS instance database, the installed backup client is automatically uninstalled. If the MySQL database is installed on a local server, you can uninstall the client as follows:

You can uninstall the client.

Linux:

CentOS

sudo rpm --erase "dbackup3-agent-mysql"
sudo rpm --erase "dbackup3-agent"
sudo rpm --erase "dbackup3-common"

Ubuntu

sudo dpkg -r "dbackup3-agent-mysql" "dbackup3-agent" "dbackup3-common"

You can delete the following directories:

Linux:

/etc/default/dbackup3*
/opt/scutech
/var/opt/scutech/
/var/log/dbackup3/
/etc/opt/scutech/

Uninstall the Oracle backup client

When you unregister an ECS instance database, the installed backup client is automatically uninstalled. If the Oracle database is installed on a local server, you can uninstall the client as follows:

You can uninstall the client.

Windows:
1. You can go to the backup client installation directory (PowerShell). For example, C:\Program Files\aliyun\unibackup>.
2. You can run the command.
```
 .\uninstall-unibackup.exe /S /NCRC
```

Linux:

CentOS

sudo rpm --erase "dbackup3-agent-oracle"
sudo rpm --erase "dbackup3-agent"
sudo rpm --erase "dbackup3-common"

Ubuntu

sudo dpkg -r "dbackup3-agent-oracle" "dbackup3-agent" "dbackup3-common"

You can clear the configuration files.
- Windows:
  You can delete all configuration files under c:\programdata\scutech.
- Linux:
  You can delete the following directories:
```
/etc/default/dbackup3*
/opt/scutech
/var/opt/scutech/
/var/log/dbackup3/
/etc/opt/scutech/
```

Uninstall the SQL Server backup client

You can uninstall the client.
- Windows:
  1. You can go to the backup client installation directory (PowerShell). For example, C:\Program Files\aliyun\unibackup>.
  2. You can run the uninstall-unibackup.exe command and follow the wizard to complete the uninstallation.
You can clear the configuration files.
- Windows:
  You can delete all configuration files under c:\programdata\scutech.

Restore issues

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. You can 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?

You can log on to the server and view the backup log.
Windows client log path: C:\ProgramData\scutech\dbackup3\agent\log\dbackup3-agent.log
In the log, you can 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.

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

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

Backup vault issues

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?

The Backup Data is the cumulative amount of data from all backup jobs. For example, if a 1 TB file is backed up twice, Cloud Backup saves two independent data copies, and the backup data size is 2 TB. Cloud Backup uses deduplication and compression to reduce backup vault usage and lower your costs. The actual Vault Usage is the basis for billing. You can view the backup data size and backup vault usage on the Overview page in the console.