Overview - Apsara File Storage NAS - Alibaba Cloud Documentation Center

You can migrate data from an on-premises storage system to an File Storage NAS (NAS) file system. This topic describes the billing of the feature, the procedure of data migration, and the migration tools for different scenarios.

Billing

When you migrate data from an on-premises storage system to a NAS file system, the following fees are incurred:

Storage usage fees of NAS file systems: We recommend that you purchase resource plans to offset the fees. For more information, see Billing overview.
Elastic Compute Service (ECS) configuration fees: If you use an ECS instance as the intermediate node for data transfer, you are charged for the ECS instance based on the instance configurations. For more information, see Overview.
Data transfer fees: If you download data from a NAS file system to your local computer, you are charged for the outbound traffic of an elastic IP address (EIP). For more information about the billing of an EIP, see Pay-as-you-go.

Procedure

To migrate data from an on-premises storage system to a NAS file system, you must configure an ECS instance as an intermediate node and then migrate data to a NAS file system by using a migration tool.

If your data center frequently reads and writes a large volume of data to and from a NAS file system, we recommend that you create a physical connection and mount the NAS file system to the data center. For more information, see Access file systems in on-premises data centers.

Migration tools

You can use various migration tools for different scenarios. The following table describes the benefits and scenarios of each migration tool. Select an appropriate migration tool based on your business needs.

Migration tool	Benefit	Scenario
Migrate data by using an SSH File Transfer Protocol (SFTP) client	Supports multiple operating systems. Provides a graphical user interface (GUI).	You need to upload a small number of files to a Network File System (NFS) file system and download data from an NFS file system to a local computer.
Migrate data by using the rsync command-line tool	Supports Linux, Windows, and macOS operating systems. You can configure crontab for your local Linux or macOS system to automatically back up data to a NAS file system. After a file is uploaded or downloaded, the metadata of the file remains unchanged, including the owner and permission information. Incremental data can be synchronized.	You need to upload and download a large number of files or you need to frequently upload and download files.
Migrate data by using the Robocopy tool	The tool is built into Windows. Supports multiple threads and resumable upload. Hundreds of millions of small files (the size of each file is about 100 KB) can be migrated. The total data size can reach up to more than 10 TB. Incremental data can be synchronized.	You need to transfer a large volume of data in Windows by running multiple threads and you need to resume interrupted data transfer.
Migrate data by using IIS FTP	Supports multiple operating systems. Provides a graphical user interface (GUI).	You need to access a Server Message Block (SMB) file system by using Internet Information Service (IIS).
Appendix: Migrate data by using the fpsync command-line tool	Supports multiple threads.	You need to migrate data to an NFS file system by running multiple threads.