Back up on-premises NAS files
You can use Cloud Backup to back up files from an on-premises network attached storage (NAS). Cloud Backup allows you to configure flexible backup policies and view or restore your data at any time. This topic describes how to back up files from an on-premises NAS.
Prerequisites
Service activation: You have activated the Alibaba Cloud Cloud Backup service. Activating Cloud Backup is free of charge, but using the NAS backup feature of Cloud Backup incurs Cloud Backup storage capacity fees. For more information, see On-premises NAS backup fees.
Network Connectivity: Your on-premises NAS can access Alibaba Cloud over the public internet. If public internet access is not available, your on-premises NAS must be interconnected with an Alibaba Cloud VPC by using an Express Connect circuit or a VPN connection. Routes must be configured from your on-premises data center to the cloud network segments
100.64.0.0/10,100.64.0.0/11, or100.96.0.0/11. For more information, see Establish a connection from a VPC to an on-premises data center (single-tunnel mode).Client installation: Install a backup client on an on-premises server. The server must be able to communicate with the on-premises NAS and Alibaba Cloud.
Limits
During on-premises NAS backup and restore jobs, the maximum length of a single file name is 248 bytes. If a file name exceeds this limit, the backup and restore of that file fails, and the job is marked as partially completed.
The shared directory for an on-premises NAS backup cannot end with a dollar sign ($).
Back up on-premises NAS files
When you create a backup plan, the first backup job is a full backup. Subsequent jobs are incremental backups by default.
on-premises NAS backup is based on a file system scanning mechanism. During a backup job, new or modified files that have not yet been scanned are backed up in the next job. Deleted or moved files might cause an "NFS File Handle invalid" error and the backup job may be partially completed. We recommend that you run backup jobs during off-peak hours.
Create a backup plan
When you create a backup plan for the first time, the new version of the console provides a persistent guided card at the top of the page. The card contains a step bar to guide you through adding a data source, configuring a client group, and creating a backup plan.
On the NAS Backup - On-premises NAS page, select a region in the top navigation bar.
NoteIf you are using the old console (Try New Version is displayed at the top of the page), under Local NAS, on the NAS Instance tab, click NAS Backup Wizard.
Add an on-premises NAS data source.
On the On-premises NAS Data Source tab, click Create Data Source.
In the Create Data Source panel, configure the parameters as described in the following table.
Parameter
Description
NAS Instance Name
The name of the NAS instance that you want to back up.
NAS Network Address
The network address of the NAS instance to back up. Obtain the network address from your file system administrator. Examples:
47.100.XX.XX or nas.company.com.NAS Shared Directory
The path relative to the root directory (
/). For example, a value of/myshareshares the /myshare path for data backup.To find the NAS shared directory, see How do I query the NAS shared directory?
Only Chinese characters, uppercase and lowercase letters, digits, and the following special characters are supported:
,-_=/.:\.NoteIn most cases, the root directory of an Apsara File Storage NAS file system that uses the NFS protocol is
/after it is mounted, while the root directory for an SMB file system is/myshare. The actual mount directory may vary. Use your actual mount directory.
Protocol Type
NFS and SMB protocols are supported. If you select SMB, you must enter a valid Username and Password.
(Optional) Click Advanced Settings, and then click Set Mount Parameters.
You can select multiple mount parameters when you mount a file system. The following table describes the parameters.
Parameter
Description
vers
The version of the file system.
vers=3: Mounts the file system by using NFSv3.
vers=4: Mounts the file system by using NFSv4.
nolock
Specifies whether to disable file locking.
proto
The protocol for mounting the file system.
rsize
Defines the size of the data block that the client uses to read data from the file system.
Recommended value: 1048576 (bytes).
wsize
Defines the size of the data block that the client uses to write data to the file system.
Recommended value: 1048576 (bytes).
hard
If File Storage NAS is temporarily unavailable, a local application that is using a file on the file system stops and waits until the file system comes back online. We recommend that you enable this parameter.
timeo
The timeout, in tenths of a second, before the NFS client retries a request.
Recommended value: 600 (60 seconds).
retrans
The number of times the NFS client retries a request.
Recommended value: 2.
Configure a backup client group and click OK.
Select the machine where the backup client is installed. You can add multiple clients to a client group to run a backup job concurrently.
You can select an existing client group or select Create Backup Client Group. To create a new group, specify a Client Group Name and select the clients to add to the group.
NoteTo avoid data transfer over the public internet and reduce costs, click Settings in the Actions column for the client. In the Client Settings panel, change Data Network from Internet to VPC and save the settings.
If you have not installed a client, see Download and activate a Linux client.
Add an on-premises NAS backup.
On the Protected On-premises NAS Data Sources tab, click Add On-premises NAS Backup.
In the Create Backup Plan panel, configure the parameters and click OK.
ImportantIf the selected region supports backup policies, you must associate the backup plan with a backup policy. Cloud Backup then periodically backs up the on-premises NAS according to the policy.
In the left-side navigation pane, click Policy Center to view the regions that support backup policies. For information about how to create a backup policy, see Create a backup policy.
Parameter
Description
Select Data Source
Select the on-premises NAS data source that you added in the previous step.
NoteThis parameter is available only in the new version of the console.
Source Paths
Enter the directory to back up. Only one directory can be specified. Wildcards are not supported.
Backup Rule
The backup rule includes the following options:
Include All Files: Backs up all files in the selected source path.
Include Files or Exclude Files: In the Enter Paths text box, enter a list of files. Files in the selected source path are backed up or excluded based on the specified rule.
The file list contains subpaths of the source path. The matching rules for these subpaths are as follows:
A pattern starting with a forward slash (
/) matches the full path relative to the source path.For example, if the backup file path is /data/share, and the file list is set to /subdir/data, then the files and directories in the /data/share/subdir/data path are backed up (or not backed up).
For example, if the backup file path is /data/share and the file list is set to /abc*, files or directories under the /data/share/abc path that match the prefix
abcare backed up (or not backed up).A pattern that does not start with a forward slash (
/) matches any file or directory with that name at any level.For example, if the backup file path is /data/share and the file list is set to abc*, files or directories in the /data/share path that match the
abcprefix are backed up (or not backed up).For example, if the backup file path is /data/share and the file list is abc, then all files or directories named abc in the /data/share path are backed up (or are not backed up).
Backup Policy
Select a backup policy from the drop-down list.
Cloud Backup automatically backs up the data source according to the selected backup policy. A backup policy defines operations such as backup vault encryption, backup interval, retention period, cross-region replication, automatic archiving, and virus detection for backup points. This helps you flexibly manage your data source assets.
If the default backup policy does not meet your needs, click Create Backup Policy or Edit Policy. For more information about the parameters in a backup policy, see Policy Center.
After the backup plan is created, its Plan Status is enabled. Cloud Backup runs backup jobs according to the specified start time and interval.
After you create the backup plan, go to the Backup Jobs tab to view the job status and confirm that the initial full backup has completed successfully.
Manage from the details page
On the NAS Backup - On-premises NAS page, select the region where your protected on-premises NAS data source is located, and then click View Details in the data source's Actions column to open its details page.
If you are using the previous version of the console, which displays a Try New Version button, go to the NAS Instance tab, click the 
icon next to the target NAS instance to expand it, and perform the operations. The procedure is the same as in timeline mode.
Backup details
On the Backup Details tab, manage your backup points as needed.
The backup history can be displayed in a list or a timeline. Click the
icon on the right side of the backup history to switch the view.If you are using the previous version of the console, which displays a Try New Version button, go to the NAS Instance tab, click the
icon next to the target NAS file system, and then click the 
icon next to the backup plan to perform the operations. The procedure is the same as in timeline mode.
Browse files
To view the files in a backup point, use the Browse feature. If virus detection was performed on the backup point, infected files are marked.
On the Backup Details tab, click Browse in the Actions column of the target backup point.
In the Browse panel, view the backed-up on-premises NAS files.
You cannot directly download backed-up files. You can restore them to a temporary NAS path free of charge and then download the files from the NAS.
Extend retention period
To retain a backup for a longer period, extend its retention period.
The retention period of a backup point can only be extended, not shortened.
This operation is not supported for backup points that are set to be retained permanently.
On the Backup Details tab, click the
icon in the Expires At column for the target backup point.Select Schedule Time or Never Expire, and then click Save.
After the configuration is complete, you can view the new expiration time in the Expires At column.
Delete data
Delete backup point data generated by the backup client.
Deleted backup points cannot be recovered. Proceed with caution.
If "Keep at least one backup version" is enabled in the backup plan, you cannot delete the latest backup. If you are sure you want to delete this backup, first disable the "Keep at least one backup version" setting in the backup plan.
On the Backup Details tab, use one of the following methods to delete backup points in list mode.
To delete a single backup point, click Delete in the Actions column of the target backup point and confirm the deletion.
To delete multiple backup points, select the target backup points, click Delete Backup Point below the list, and confirm the deletion.
Backup plan
Switch to the Backup Plan tab to manage backup plans as needed.
Run immediate backup
In the Actions column of the backup plan, choose to start a backup job immediately.
Modify plan
Click Modify in the Actions column of the backup plan.
In the Configure Plan panel, modify basic settings and the backup policy as needed.
Click OK.
Pause or resume plan
Backup plans are enabled by default. If you need to stop data backups for a specific period, you can pause the backup plan and resume it later.
Pause a backup plan: Turn off the switch in the Plan Status column or choose from the Actions column and confirm the action.
After a backup plan is paused, subsequent backup jobs will not run. Existing backup points are not affected and will expire according to their retention period. However, if "Keep at least one backup version" is enabled, the last backup version is retained regardless of the retention period. Billing for the on-premises NAS data source continues as long as it has existing backup points.
Resume a backup plan: After pausing a backup plan, turn on the switch in the Plan Status column or choose from the Actions column.
Delete plan
You cannot delete a backup plan if the on-premises NAS data source has existing backups. You must delete the backup data first. If you want to stop the backup plan from running before you delete the data, you can pause the plan.
A deleted backup plan cannot be recovered. Cloud Backup also removes the corresponding on-premises NAS data source from the list of protected data sources.
Select the target backup plan, click Delete Plan below the list, and confirm the deletion.
Alert settings
In the Actions column of the backup plan, choose to configure alert notification methods and contacts for the backup plan.
Alert Method: Supported methods include Disabled, Same as Backup Vault, Notify Primary Account, and Custom.
Alert Contacts: If you set the alert method to Custom, select the contacts or contact groups to receive alert notifications.
Backup jobs
At the scheduled backup time, Cloud Backup starts the backup job.
The backup progress percentage is dynamically estimated by the system based on the current data volume and is for reference only. It does not indicate an exact completion ratio. During the backup process, the displayed total scanned size may be smaller than the actual total data size because data scanning may not be complete. Use the final status of the backup job as the source of truth.
Backup jobs completed on or after 2025-06-01 display statistics for data volume and file count for Total Scanned at Source, Backup Completed, and Data Written to Vault. For backup jobs completed before this date, only data volume statistics are displayed.
On the Backup Jobs tab, a Status of Completed indicates that the backup was successful. You can view details for the backup job, such as Total Scanned Data Amount at Source, Completed Backup Data Amount, Data Amount Written to Backup Vault, and Backup Speed. See the tooltips in the Cloud Backup console for descriptions of these metrics.
To cancel a running job, click Cancel in the Actions column of the backup job and confirm the cancellation.
Backup status
Status | Description |
Ready | The data source has been added and is awaiting its first backup. |
Backing Up | The data source is protected, and the system is waiting for the next scheduled backup. |
Backing Up (In Progress) | A backup job is in progress. |
Paused | All backup plans for this resource are paused. You can enable any backup plan in the backup plan list on the details page to resume backups. |
Stopped | The source data cannot be found, possibly because it was deleted. The backup data is automatically deleted after it expires. You can view the expiration time or restore data from the backup history list on the details page. |
Client group
In the Client Group Information section, manage backup clients as needed.
If you are using the previous version of the console, which displays a Try New Version button, go to the NAS Instance tab and click View Client Group for the target NAS instance. The previous version does not display the client list directly.
Reinstalling a backup client from the console is supported only in the new version of the console.
You cannot uninstall on-premises clients from the console. To uninstall a client manually, see How do I uninstall a Cloud Backup client?.
Reinstall client
To the right of Client Operation, choose . After the installation is complete, the client status updates to Activated.
Client settings
To the right of Client Operation, click Client Settings to configure and save client parameters. We recommend that you use the default settings.
Setting | Description |
Use HTTPS to Transfer Data | Specifies whether to transmit data over HTTPS. The HTTPS encryption and decryption process can affect transmission performance. Changes take effect when the next backup or restore job starts. Note This setting affects data security only during network transmission. Regardless of whether HTTPS is enabled, backup data is always encrypted when stored in the backup vault. |
Data Network | Select whether to transmit data over a VPC or the public internet. If your client is deployed in an Alibaba Cloud VPC or is connected from your on-premises environment to an Alibaba Cloud VPC over a leased line, select VPC as the transmission network. |
Manage group
Click Edit Backup Client Group. In the Edit Backup Client Group panel, you can modify the client group name, add clients to the group, or remove clients from the group.
Enterprise features
Virus detection
To prevent infected files from being restored to your production environment, Cloud Backup provides the Backup point virus detection feature. This helps you select an uninfected backup point for future restores. On the Backup Details tab, in the Backup History section, find the backup point you want to scan, click ┇ in the Actions column, and then select .
In Backup Details, click in the Actions column of the target backup point.
Vault replication
To prevent regional disasters or account management risks from affecting business continuity, Cloud Backup supports configuring Cross-region backup or Cross-account backup vault replication for backup vaults where the Storage Vault Type is General Backup. Once configured, data from the source backup vault is automatically synchronized to the destination backup vault, ensuring data consistency between the two locations. You can also perform cross-region data recovery from the destination backup vault as needed.
For Standard backup vaults that store on-premises NAS files, configuring backup vault replication enables cross-region or cross-account disaster recovery.
In addition, on-premises NAS backup supports enterprise features such as cross-account backup, automatic archiving, KMS encryption, immutable backups, and virus detection.
Manage on-premises NAS data sources
On the NAS Backup - On-premises NAS page, select the region where the target NAS instance is located. Then, on the On-premises NAS Data Source tab, you can edit or delete the NAS data source.
The ... menu in the Actions column for a NAS instance also includes Edit Backup Client Group, which allows you to directly adjust the client group configuration for the NAS instance. For detailed instructions, see Manage a client group.
If you are using the previous version of the console, which displays a Try New Version button, go to the NAS Instance tab to perform the corresponding operations.
Edit instance information
In the Actions column of the NAS instance, choose .
In the Edit NAS Instance dialog box, modify the NAS instance information.
Click OK.
Delete data source
If the NAS instance is associated with a backup plan or has backup data, it cannot be deleted.
Deleting an on-premises NAS data source also deletes all historical backups created for that data source. Confirm that you no longer need the corresponding backup data before you proceed. Deleted on-premises NAS data sources and their historical backups cannot be recovered. Proceed with caution.
Click Delete in the Actions column of the NAS instance and confirm the deletion.
Troubleshooting
If the Status of a backup plan or backup job is abnormal, follow the UI prompts to modify and confirm the configuration, or use the following methods to troubleshoot the issue.
Symptom | Cause | Solution |
Backup job fails |
|
|
The backup plan is paused. | The backup plan is paused, and Cloud Backup no longer protects the on-premises NAS. | Resume the backup plan to continue protecting your data. |
The backup job is partially completed. | A file was deleted or moved during the backup process, which caused an "NFS File Handle invalid" error. | Rerun the backup job during off-peak hours. |
If you need more help, contact online technical support. When you submit a ticket, provide the backup plan ID, region, data source type, and job ID. Describe the issue, including when it occurred, the steps you took, any error messages, and the expected outcome.
Related documentation
Cloud Backup provides resource plans for various backup scenarios. These plans offer greater discounts to help you minimize costs. For more information, see Resource plan purchase guide.