This topic describes how to roll back a disk by using a snapshot. When the system does not respond or an incorrect operation is performed, you can roll back a disk to a previous version by using its snapshots. Before you roll back a disk, you must have created at least a snapshot of the disk. If you roll back system disks, the current SSH key pairs or usernames and passwords of the instances remain bound to the disks after the disks are rolled back.
Prerequisites
- A snapshot of the disk to be rolled back is created, and no new snapshot is being
created for the disk. For more information, see Create a normal snapshot or Create a local snapshot.
Warning The rollback operation is irreversible. After a disk is rolled back, the data that you added, deleted, or changed from the creation of the snapshot to the time when the disk is rolled back is lost. To avoid data losses caused by incorrect operations, we recommend that you create a snapshot for the current disk before you roll back the disk.
- The disk has not been released.
- After you replace the system disk, snapshots of the previous system disk cannot be used to roll back the new system disk.
- If you use a disk to create a dynamic extended volume or redundant array of independent disks (RAID), you must stop all I/O operations on the disk before you roll back the disk.
- The disk is attached to an ECS instance and the instance is in the Stopped state.
For more information, see Attach a data disk and Stop an instance.
Notice A pay-as-you-go instance in a VPC may not be restarted after its disk is rolled back if the No Fees for Stopped Instances (VPC-Connected) feature is enabled. We recommend that you select Retain Instance and Continue Charging After Instance Is Stopped when you stop the instance.
Roll back a disk by using a snapshot
You can roll back a disk from the Snapshots or Instances page. The following example shows how to roll back a disk from the Instances page.
(Optional) Synchronize data after a disk is rolled back

What to do next
- After a disk is rolled back, the host configuration file and the configuration data such as the hostname, SSH, password, network, system source, and clock source are initialized. You must reconfigure the information.
- If you resize a disk after you create a snapshot for the disk, the size of the disk is also rolled back after you roll back the disk. To make the disk revert to the size before the rollback, you must log on to the instance to resize the file system again.