File Storage NAS:Migrate data from a NAS file system to an on-premises storage system

Select a migration method

Select a method based on your scenario:

Use an SFTP client

Procedure

1. Install an SFTP client on your local operating system.

   Various SFTP clients are available. This topic uses FileZilla as an example. Download and install an SFTP client that is compatible with your local operating system.

2. Establish a connection between the SFTP client and the transit node ECS instance.

   1. Open the FileZilla client, configure it as described below, and click Quickconnect to establish a connection.

      After a connection between the local client and the ECS instance is established, the local file system is displayed on the left and the file system of the ECS instance is displayed on the right.

      Parameter	Description
      Host	The public IP address of the transit node ECS instance. For example, 192.0.2.1.
      Username	The username of the transit node ECS instance. The user must have read and write permissions on the NAS file system directory. For example, root. Note The default username of a Linux ECS instance is root or ecs-user. The default username of a Windows ECS instance is administrator.
      Password	The login password of the transit node ECS instance. For example, the login password of the root user. Note To reset a forgotten login password, see Reset the login password of an instance.
      Port	The SFTP port number. The default value is 22.

   2. In the right pane, enter the mount path of the NAS file system, such as /mnt, in the Remote site field. Press Enter to view the files in the NAS file system.

      

3. Download data.

   Drag and drop one or more files or directories from the right pane to the left pane to download the data.

Use rsync

Benefits

• Preserves file metadata, including owner and permission information.

• Supports incremental data synchronization.

• Supports crontab scheduling on Linux or macOS for automated backups.

Procedure

1. Install the rsync tool.

   Linux

   Operating system	Command
   CentOS	Use the yum package manager to install rsync. sudo yum install rsync
   Redhat
   Ubuntu	Use the apt package manager to install rsync. sudo apt-get install rsync
   Debian

   Note

   If you are using a different version of Linux, use the corresponding package manager to install rsync.

   macOS

   Download and install the Homebrew package manager, and then run the following command to install rsync:

   brew install rsync

   Windows

   • Download and install the Cygwin simulation environment. During installation, search for and install rsync. Alternatively, download, compile, and install rsync manually.

     Note

     You must enable the SSH TCP port 22 for the security group of the associated virtual private cloud (VPC).

2. Download data.

   Run the following command to download data from the NAS file system to a local directory:

   rsync -avP root@192.0.2.0:/mnt/DirToSync/ DirToSync/

   Parameter	Description
   192.0.2.0	The public IP address of the Linux or Windows ECS instance on which the NAS file system is mounted.
   /mnt/DirToSync	The directory to export from NAS.
   DirToSync	The local directory.

   Note

   The path in the rsync command must end with a forward slash (/). Otherwise, the paths do not match after the data is synchronized.

Use Robocopy

Benefits

Robocopy is a Windows directory copy command. It creates mirror copies with identical file structures without duplicating unchanged files, and preserves file information such as dates and timestamps.

For large-scale data migration, install Python on a Windows ECS instance and use the migration.py script. For more information, see How do I accelerate data migration to an SMB file system?

Procedure

1. Log on to the Alibaba Cloud ECS instance that is used for data migration.

2. Migrate the data.

   Run the following command to migrate data from the source file system (drive Z) to the destination file system (drive Y).

   robocopy Z:\ Y:\ /e /w:5 /z /mt:32

   Note

   Only the data in the specified folder is migrated. The folder itself is not migrated.

   The following table describes important fields. Modify the values as needed.

   Parameter	Description
   /mt	Sets the number of concurrent threads. The default value is 8. The value can be an integer from 1 to 128. In this example, 32 threads are used for multi-threaded replication.
   /w	Sets the interval in seconds between retries.
   /z	Enables resumable transfer.
   /e	Copies all subdirectories, including empty ones.
   /copyall	Copies all file information. This includes: Data Properties Timestamps Access control list (ACL) Owner information Auditing information

   Note

   To accelerate the migration of large amounts of data, such as hundreds of millions of small files that exceed 10 TB, install the latest Python program on a Windows ECS instance to perform the migration. For more information, see How to accelerate data migration to an SMB file system.

3. Check the migration result.

   After the migration is complete, run the following Robocopy command to verify that the destination file system is consistent with the source file system.

   ROBOCOPY Z:\ Y:\ /e /l /ns /njs /njh /ndl /fp /log:reconcile.txt

   The following table describes important fields. Modify the values as needed.

   Parameter	Description
   /e	Lists only folders, including empty ones.
   /l	Does not modify or copy files. It only records differences.
   /fp	Includes the full path of files in the log. This is necessary only if you omit /ndl.
   /ns	Does not include file sizes in the log.
   /ndl	Does not include folders in the log.
   /njs	Does not include the job summary.
   /njh	Does not include the job header.
   /log:reconcile.txt	Writes the migration result to the reconcile.txt log. If the log file already exists, it is overwritten.

Use IIS FTP

Procedure

For more information, see Set up the Windows IIS web service.

Transfer via OSS

Sync data to OSS using ossutil or Data Transport, then download from OSS to local storage.

1. Migrate data to OSS.

   • Use ossutil to migrate data to OSS. For more information, see Migrate data by using ossutil.

   • Use the Data Transport service to migrate data from NAS to OSS. For more information, see Migrate data by using Data Transport.

2. Download the data from OSS to local files. For more information, see Simple download.