Help Center/ Business Recovery Service/ FAQs/ Asynchronous Replication/ What Can I Do If the Disaster Recovery Site VM Is Not Started After a Switchover?
Updated on 2025-09-10 GMT+08:00

What Can I Do If the Disaster Recovery Site VM Is Not Started After a Switchover?

Possible Cause

BRS asynchronous replication supports crash consistency. During a switchover, data in the memory may be lost, so the disaster recovery site VM may need to use the crash recovery capability of the application or file system to restore data. In most cases, the restored data is consistent and can be normally used.

Solution

Example: After a switchover, the disaster recovery site VM failed to be started. An XFS exception occurred (LSN verification failed), and the OS entered the emergency mode.

Solution: Run journalctl to check that the fault is caused by an XFS file system error. Enter the emergency mode of the OS and run xfs_repair to rectify the fault.

An operation example is provided as follows:

  1. Check the root file system, for example rhel-root, in the /dev/mapper directory.

    xfs_repair /dev/mapper/rhel-root

    If an error is reported, check the error cause or run the following command:

    xfs_repair –L /dev/mapper/rhel-root

    Information similar to the following is displayed.

  2. Check whether the repair is successful. Run the following command:

    mount /dev/mapper/rhel-root / 

    If the mount is successful, the file system has been repaired.

  3. Restart the OS.

    Run reboot. After the reboot, the VM OS can be accessed.