To prevent data loss or corruption in a General-purpose NAS file system, you can use Cloud Backup to back up all its directories and files. Cloud Backup lets you configure flexible backup policies to back up data to the cloud. You can view and restore your data at any time. This topic describes how to use Cloud Backup to back up files in a General-purpose NAS file system.
Prerequisites
You have activated the Cloud Backup service. Activating Cloud Backup is free. However, you are charged for using the NAS backup feature of Cloud Backup. The fees include storage capacity fees. For more information, see Billing of NAS backup.
Background information
In this topic, NAS refers to the Alibaba Cloud General-purpose NAS file system.
Alibaba Cloud NAS backup supports file shares that use the NFS and SMB protocols. Cloud Backup can back up both mounted and unmounted NAS file systems. The backup procedure is the same for both. Cloud Backup does not create file system snapshots when it backs up a NAS file system. Instead, it uses an efficient file system scanning mechanism.
Cloud Backup does not currently support the NAS SMB ACL feature. If you enable the ACL feature for your SMB file system, Cloud Backup cannot back up the access control configurations.
Cloud Backup supports data backups for the Standard and IA storage classes of General-purpose NAS. It does not support data backups for the Archive Storage class.
If a backup job for an SMB NAS file system fails due to permission issues, grant the Cloud Backup client read permissions on the SMB NAS files and use ECS File Backup to back up the SMB NAS files.
You can also use ECS File Backup to back up NFS NAS files.
Limits
Limitations | Description |
Single file name length | Maximum of 248 bytes. If this limit is exceeded, the backup and restoration of the file fail, and the task is partially completed. |
Unsupported file types for restoration | Socket files and hard links |
Unsupported storage classes | Archive Storage data |
SMB ACL | Does not support backing up access control configurations. |
Number of files in a single backup job | The recommended maximum value is 50 million. |
Number of files and subdirectories in a single directory | The total cannot exceed 8 million. |
Notes
When you create a backup plan or associate a backup policy for the first time, Cloud Backup automatically creates the service-linked role AliyunServiceRoleForHbrNasBackup to obtain the required resource permissions. Follow the prompts in the authorization dialog box to grant the permissions.
Operation video
The product name has been changed to Cloud Backup, and all related products and services will use the new name. The services and features remain unchanged, and you do not need to make any adjustments. For more information, see [Upgrade] Notice on changing the product name of Hybrid Backup Recovery to Cloud Backup.
Back up NAS files
Each NAS backup job should contain no more than 50 million files. The total number of files and subdirectories in a single directory should not exceed 8 million.
After you create a backup plan, the first backup job is a full backup. Subsequent jobs are incremental backups by default.
Create a backup plan
Follow these steps to back up a NAS file system in the same region.
In the upper part of the NAS Backup - Alibaba Cloud NAS page, select the region where the target NAS file system is located, and then click Add NAS Backup.
NoteIf you are using the Legacy Console (the Try New Version button is displayed in the upper-right corner), on the Alibaba Cloud NAS tab, click Create Backup Plan.
In the Create Backup Plan panel, configure the parameters as described in the following table, and then click OK.
NoteEach NAS file system is eligible for a 30-day free trial backup plan. The free trial is offered at the resource level, not the account level. After you select a NAS file system, the system automatically determines whether the file system qualifies for the free trial and displays the corresponding creation form. To use the paid mode directly, click Switch to Paid Plan in the free trial form. For more information, see 30-day Free Trial.
From the File System drop-down list, select the file system that you want to back up. Then, configure the parameters based on the creation form.
Free backup plan
ImportantFor a free plan, the backup vault is automatically created by the system. You cannot select an existing vault or customize the vault name. The vault is always encrypted using the fully managed encryption method of Cloud Backup.
For a free plan, the source path is fixed to the root directory (
/). The backup cycle and retention policy are automatically configured by the system and cannot be edited. Each free plan uses a separate backup vault. After you switch to a paid plan, you cannot change the vault. To back up all data to the same vault, do not use the free trial plan.
Configure the following parameters and click OK.
Parameter
Description
Pay After Trial Ends
Specifies whether to renew the free backup plan as a paid plan after it expires.
Backup Plan Name
The system automatically generates a default name. You can also specify a custom name.
Paid backup plan
Configure the following parameters and click OK.
Parameter
Description
Source Paths
Enter the path that you want to back up. For example,
/nas/folder.Backup Rule
Configure rules for the backup directory. Only directories that meet these rules are backed up.
Backup File Type
Select the type of files to back up.
Backup Policy
From the drop-down list, select a backup policy. Cloud Backup automatically backs up the data source based on the policy. The policy includes settings such as encryption method, backup interval, retention period, cross-region replication, automatic archiving, and virus scan. If the default policy does not meet your needs, click Create Backup Policy or Edit Policy to customize one.
NoteThe backup directory rule and backup file type are advanced parameters. To display them, select the Advanced Rule Mode check box in the Create Backup Plan panel.
After the backup plan is created, its status changes to Running. Cloud Backup automatically runs backup jobs based on the specified start time and backup interval. The list of protected resources is updated as follows:
If the NAS file system already has a backup plan, the count in the Backup Plans column increases by 1.
If the NAS file system does not have a backup plan, it is added to the list of protected resources, and the number in the Backup Plans column is 1.
Backup status description
Backup status | Description |
Ready | The resource has just been added to the list of protected resources and is awaiting its first backup. |
Backing Up | The backup status is normal. The system is waiting for the next backup job to run. |
Backing Up (In Progress) | The backup status is normal, and a backup job is in progress. |
Paused | All backup plans for this resource are paused. You can go to the backup details page and enable any backup plan in the backup plan list to resume backups. |
Stopped | The backup resource cannot be found (it may have been released). The backup data will be automatically deleted after it expires. |
View backup jobs
When the scheduled start time is reached, Cloud Backup starts the backup job.
The backup progress percentage is a dynamic estimate that is generated by the system based on the current data volume and is for reference only. It does not represent the exact completion percentage. During the backup process, the displayed total scanned size may be smaller than the actual total data size because the data scan may not be complete. The final status of the backup job is the definitive status.
On the Backup Jobs tab, if the Status of a backup job is Completed, the backup was successful. You can view details of the backup job, such as Total Scanned Size, Completed Backup Size, Vault Write Size, and Backup Speed. For descriptions of these metrics, see the tooltips in the Cloud Backup console.
For backup jobs completed on or after June 1, 2025, statistics for data volume and file count will be displayed for Total Scanned Size, Completed Backup Size, and Vault Write Size. For backup jobs completed before this date, only data volume statistics are shown for these metrics.
Only backup job records from the last six months can be viewed in the task list. To access older data, you can export the data using the Reports feature.
To cancel a backup job that is in progress, click Cancel in the Actions column of the backup job and confirm the cancellation.
Manage backup content
In the upper section of the NAS Backup - Alibaba Cloud NAS page, select the region where the target NAS file system is located. Click View Details to the right of the target file system. On the Backup History tab, you can manage the backup content as needed.
If you are using the Legacy Console (the Try New Version button is displayed in the upper-right corner), on the Backup Plans tab, click the expand icon for the target file system to perform the corresponding operations.
The backup details list shows information such as the source path, completion time, time-to-live (TTL), backup data size, backup ID, backup vault ID, backup policy ID, backup storage tier (Standard/Archive), virus scan status, and backup status.
Browse backup files
Use the Browse feature to view backed-up files. If a virus scan has been performed on the backup point, Cloud Backup marks the infected files.
On the Backup History tab, click Browse in the Actions column of the target backup point.
You can also click the
icon on the right side of the backup history, switch the display mode, click the target backup point, and select Browse.In the Browse panel, view the backed-up NAS files.
You cannot directly download backed-up files. You can restore the files to a specified temporary NAS path free of charge, and then download the files from the NAS file system.
Extend the retention period of a backup point
To save backup data for a longer period, you can extend the retention period of the backup point.
The retention period of a backup point can only be extended, not shortened.
Backup points set to be retained permanently cannot be extended.
In Backup History, click the
icon in the Expires At column of the target backup point.Alternatively, click the
icon on the right side of the backup history to switch the display mode. Then, click the target backup point and click the 
icon to the right of Expires At.Set a Schedule Time or select Never Expire, and then click Save.
After the setting is complete, you can view the new expiration time in the Expires At column.
Delete backup data
Deleted backup points cannot be recovered. Perform this operation with caution.
If 'Keep at least one backup version' is enabled in the backup policy, you cannot delete the latest backup. To delete it, first disable this setting in the backup policy.
After a backup plan is deleted, Cloud Backup removes the NAS file system from the backup list when the last backup point expires or is deleted.
On the Backup History tab, in list mode, you can delete a backup point in one of the following ways.
Delete a single backup point: Click Delete in the Actions column of the target backup point and confirm the deletion.
Delete backup points in a batch: Select the target backup points, click Delete Backup Point below the list, and confirm the deletion.
You can also click the icon on the right side of the backup history, switch the display mode, click the target backup point, and select Delete.
Manage backup plans
In the upper section of the NAS Backup - Alibaba Cloud NAS page, select the region where the target NAS file system is located. Click View Details to the right of the target file system. Switch to the Backup Plans tab to manage backup plans as needed.
If you are using the Legacy Console (the Try New Version button is displayed in the upper-right corner), on the Backup Plans tab, select a feature from the Actions column of the target file system.
Run a backup immediately
In the Actions column of the backup plan, select to run a backup immediately.
Modify a backup plan
Click Modify in the Actions column of the backup plan.
In the Modify Plan panel, modify the basic settings and backup policy as needed.
Click OK.
Pause or resume a backup plan
Backup plans are enabled by default. To pause data backups, you can pause the backup plan and resume it when needed.
Pause a backup plan: Turn off the switch in the Plan Status column or select from the Actions column, and then confirm the pause.
After the plan is paused, subsequent backup jobs will not run. Existing backup points are not affected and will expire according to their retention period. If the 'Keep at least one backup version' option is enabled in the backup policy, the last version will not be affected by the retention period. If there are still backup points for the NAS file system after the plan is paused, billing will continue.
Resume a backup plan: Turn on the switch in the Plan Status column or select from the Actions column.
Configure alerts
In the Actions column of the backup plan, select to configure alert notifications for backup jobs. If a backup fails or an exception occurs, Cloud Backup sends notifications based on your configurations.
Delete a backup plan
If you no longer need periodic backups, you can delete the backup plan.
Deleted backup plans cannot be recovered. Perform this operation with caution.
In the Actions column of the backup plan, select , and then confirm the deletion.
Cancel a NAS backup
To cancel a NAS backup, delete the backup plan and all backup data.
Enterprise-level features
Virus scan
To prevent files containing viruses from being restored to the production environment, the Cloud Backup service provides the backup point virus scan feature. This helps you select clean and safe backup points for future data restoration. On the Backup Details tab, in the Backup History area, select in the Actions column of the target backup point to scan the files for viruses.
On the Virus Scan tab of the backup details page, you can view the virus scan results for all backup points, including the following columns:
Column name | Description |
NAS File System | The identifier of the backed-up NAS file system |
Backup path or Backup ID | The source path and the backup point ID |
Backup Vault Name/ID | The name and ID of the associated backup vault |
Backup Completion Time | The time when the backup was completed |
Last Scan Time | The time when the last virus scan was performed |
Last Scan Content | The scope of the content that was scanned |
Last Scan Status | The status of the scan task |
Scanned Files/Total Files | The number of scanned files out of the total number of files |
Scan Result | The scan result (Safe/Threats found) |
You can manually scan a backup point in the backup details, or enable scanning in the associated backup policy.
Backup vault replication
To ensure business continuity in the event of regional disasters or account management risks, Cloud Backup lets you configure cross-region backup or cross-account replication for backup vaults of the General Backup Vault Type. After you configure replication, data from the source vault is automatically synchronized to the replication target vault to ensure data consistency between the two locations. You can also perform cross-region data restoration from the replication target vault as needed.
For general backup vaults that store NAS files, you can configure vault replication to achieve cross-region or cross-account disaster recovery.
In addition, NAS backup also supports enterprise-level features such as cross-account backup, automatic archiving, KMS encryption, backup locking, backup point virus scan, and automatic association of backups based on tags.
Troubleshoot backup errors
If the Status of a backup plan or backup job is abnormal, you can use the following suggestions to troubleshoot the issue.
Backup job Status: Failed (The path cannot be accessed.)
The path specified for Source Paths in the backup plan does not exist. On the Backup Plans tab, find the target file system, click ┇ > Modify Plan in the Actions column, and change the source path to the correct one.
Backup job Status: Failed (The specified file system does not exist.)
The Alibaba Cloud NAS file system has been deleted.
If the deletion was intentional: You can ignore the backup job status. To avoid incurring additional backup storage fees, in the navigation pane on the left, click Storage Vaults and delete the corresponding vault.
If the deletion was accidental: Create a new Alibaba Cloud NAS file system in the corresponding region to serve as the restore destination. Then, you can restore the files. For more information, see Create a NAS restore job.
Backup plan Status: Suspended
The backup plan is paused. Cloud Backup no longer runs backup jobs. We recommend that you enable the backup plan as soon as possible.
Create a NAS restore job
In the upper section of the NAS Backup - Alibaba Cloud NAS page, select the region where the target NAS file system is located, and then click View Details to the right of the target file system.
NoteIf you are using the Legacy Console (the Try New Version button is displayed in the upper-right corner), on the Backup Plan tab, click the
icon for the target instance to perform the corresponding operation. The operations in the Legacy Console are the same as those after switching the display mode by clicking the icon.On the Backup History tab, click Restore in the Actions column of the target backup point.
You can also click the
icon on the right side of the backup history, switch the display mode, click the target backup point, and select Restore.NoteSelect an appropriate historical backup point. The backup data may differ among backup points.
In the Create Restore Job panel, configure the following information.
In the Select Backup step, confirm or change the backup point to restore, and then click Next.
In the Select Items to Restore step, select the Restore Items, and then click Next.
Parameter
Description
Restore Items
Select the items to restore.
All files: All files from the selected source NAS instance will be restored.
Specified files: Select the folders or files to restore. You can also manually enter a file list in the Enter Paths box to restore specified files from the selected NAS instance based on rules.
Exclude specified files: Select the folders or files that you do not want to restore. You can also manually enter a list of files to exclude in the Enter Paths box. All other files will be restored.
Enter one path per line in the file list. Each line must start with the last folder of the source backup path. For example, if the backup path is /test/data and you want to restore file.txt and abc from the data folder, enter the paths in the following format.
/data/file.txt /data/abcIn the Restore Destination step, select the File System in the region to which you want to restore, and then click Next.
In the Destination Path step, configure the restore path, and then click Create.
Parameter
Description
Restore Path Type
Select the restore path type.
Specified path: Configure a new path and restore the files to this directory.
Original path: Restore the files to the original path from which they were backed up.
Destination Path
This parameter is required only when Restore Path Type is set to Specified path. It specifies the restore path. For example, /nas/abc.
If a file with the same name exists in the restore path
Skip this file.
Overwrite the file with the same name in the restore path.
Compare update times (accurate to the second) and keep the latest version.
Scan for viruses upon restoration
If you enable this feature, Cloud Backup scans all files for viruses during restoration. Files that are detected as safe are restored directly. Files that are detected as viruses are not restored. You can find a safe version on the virus scan page.
After the restore job is created, you can view its progress in the Status column on the Restore Jobs tab.
NoteTo cancel a restore job that is in progress, click Cancel in the Actions column of the restore job and confirm the cancellation.
icon for the target instance to perform the corresponding operation. The operations in the Legacy Console are the same as those after switching the display mode by clicking the References
Back up an Alibaba Cloud CPFS (NFS protocol) file system
Cloud Backup provides resource plans for various backup scenarios that offer better pricing. For more information, see Purchase a resource plan.
The data synchronization feature of Cloud Backup supports synchronizing many OSS files from a source to a destination.