File Storage NAS:Configure cross-zone disaster recovery for a General-purpose NAS file system

Mount the file systems

1. Log on to the ECS console. Click Create Instance. On the Custom Launch page, configure the following parameters:

   Parameter	Value
   Region	Same region as the file systems. In this example, China (Hong Kong).
   Network and Zone	Same VPC as the file systems. Same vSwitch as the file system (recommended).
   Instance	Minimum specification.
   Image	CentOS. In this example, CentOS 7.6.
   Storage	Click Elastic Ephemeral Disk|NAS File System|Dedicated Block Storage Cluster(Optional), then click Add File System to add both the business file system and the disaster recovery file system.

   

2. After the ECS instance is created, verify that both file systems are mounted: The business file system is mounted to /mnt/src and the disaster recovery file system is mounted to /mnt/dst.

      mount | grep nas.aliyuncs.com

   

Install rsync

sudo yum install -y rsync

Perform a full data synchronization

1. Create a target directory in the disaster recovery file system:

      mkdir /mnt/dst/backupsystem

2. Synchronize all data from the business file system to the disaster recovery file system:

      rsync -avP /mnt/src/ /mnt/dst/backupsystem/

3. Verify the synchronization completed without errors by checking the rsync output for a summary line showing the total number of files transferred.

Synchronize incremental data

If applications write data to the business file system during or after the full synchronization, run the following command to synchronize incremental changes:

rsync -avP --delete /mnt/src/ /mnt/dst/backupsystem/

Configure a scheduled task

Use crontab to schedule automatic incremental synchronization.

1. Open the crontab editor:

      crontab -e

2. Add the following line to run incremental synchronization daily at 00:30: The five fields before the command define the schedule: Adjust the schedule based on your RPO requirements. A more frequent schedule reduces potential data loss but increases resource usage.

   Field	Value	Meaning
   Minute	30	Run at minute 30
   Hour	00	Run at hour 00 (midnight)
   Day of month	*	Every day
   Month	*	Every month
   Day of week	*	Every day of the week

      30 00 * * * rsync -avP --delete /mnt/src/ /mnt/dst/backupsystem/ > /tmp/last_rsync_result.log 2>&1 &

3. Verify the scheduled task is saved:

      crontab -l

Check the synchronization result

After the scheduled task runs, check the log:

cat /tmp/last_rsync_result.log

Mount the file systems

1. Log on to the ECS console. Click Create Instance. On the Custom Launch page, configure the following parameters:

   Parameter	Value
   Region	Same region as the file systems. In this example, China (Hong Kong).
   Network and Zone	Same VPC as the file systems. Same vSwitch as the file system (recommended).
   Instance	Minimum specification.
   Image	Windows Server. In this example, Windows Server 2019.
   Storage	Click Elastic Ephemeral Disk|NAS File System|Dedicated Block Storage Cluster(Optional), then click Add File System to add both the business file system and the disaster recovery file system.
   Public IP Address	Select Assign Public IPv4 Address to download the migration tool.

   

2. After the ECS instance is created, verify that both file systems are mounted: Expected output shows the business file system mounted on X drive and the disaster recovery file system mounted on Y drive:

      net use

      Status       Local        Remote                      Network
   
      -------------------------------------------------------------------------------
      OK           Y:        \\12e4874****-v****.cn-hongkong.nas.aliyuncs.com\myshare
                                                      Microsoft Windows Network
      OK           X:        \\12f7094****-c****.cn-hongkong.nas.aliyuncs.com\myshare
                                                      Microsoft Windows Network

Install rsync

1. Download rsync for windows.

2. Decompress the downloaded installation package to C drive and rename the folder to cwRsync.

Perform a full data synchronization

Open the Command Prompt and run the following commands. Replace X and Y with the actual drive letters.

cd c:\cwRsync
rsync.exe -avP /cygdrive/X/ /cygdrive/Y/ --no-perms --no-owner --no-group

Synchronize incremental data

Run the following command. Replace X and Y with the actual drive letters.

rsync.exe -avP --delete /cygdrive/X/ /cygdrive/Y/ --no-perms --no-owner --no-group > c:/rsync.log

Configure a scheduled task

1. Create a script file named dailyrsync.bat on C drive with the following content. Replace X and Y with the actual drive letters.

      c:\cwRsync\rsync.exe -avP --delete /cygdrive/X/ /cygdrive/Y/ --no-perms --no-owner --no-group  > c:\run.log

2. Open the Control Panel and click System and Security. In the Administrative Tools section, click Schedule tasks.

3. In the Task Scheduler window, choose Actions > Create Task.

4. Click the General tab, enter a task name in Name, and select Run only when user is logged on.

5. Click the Triggers tab. Click New Trigger. Select On a schedule for Begin the task, select Daily, and specify the execution time. In the Advanced settings section, select Enabled. Click OK.

6. Click the Actions tab. Click New Action. Select Start a program for Action. In the Program/script section, select the dailyrsync.bat script file created on C drive. Click OK.

7. Click OK.

8. Restart the ECS instance and verify that the scheduled task appears in Task Scheduler.

   

Check the synchronization result

After the scheduled task runs, check rsync.log on C drive to confirm the output of the most recent incremental data synchronization.