The Alibaba Cloud snapshot service is an agentless backup service that allows you to create crash-consistent snapshots for system disks or data disks. You can use snapshots to back up data, restore Elastic Compute Service (ECS) instances that were released by mistake, and create custom images. You can create snapshots of disks to improve fault tolerance for operations before you roll back a disk, modify key system files, or change the operating system of an instance.
Prerequisites
- The disk is in the In Use or Unattached state.
- If the disk is in the In Use state, the ECS instance is in the Running or Stopped state.
Background information
It can take several minutes to create a snapshot based on the size of the disk. The first snapshot of each disk is a full snapshot and takes longer to create. Subsequent snapshots of the disk are incremental snapshots. It does not take as long to create an incremental snapshot, and the amount of time required varies based on the amount of data changed since the previous snapshot. The more data that has changed, the longer it takes.
- Do not perform operations that change the state of the ECS instance, such as stopping or restarting the instance.
- You are charged for snapshots. For more information, see Snapshots.
- We recommend that you create snapshots during off-peak hours because snapshot creation degrades the I/O performance of disks by up to 10% and slows down data reads and writes.
- While snapshots are being created, the incremental data generated by disk operations is not included in the snapshots.
- If you create an extended volume from a single multi-partition disk, the snapshot that you created can be used to roll back the disk.
- When a disk is used to create a dynamic extended volume or a RAID array, we recommend that you create a snapshot-consistent group and enable the application-consistent snapshot feature. For more information, see Create snapshots for multiple disks together by creating an instance snapshot and Create application-consistent snapshots in the ECS console.
- Created snapshots are permanently stored unless you delete them. We recommend that you delete unnecessary snapshots on a regular basis to prevent extra fees incurred by snapshot storage.
Create a snapshot in the ECS console
You can go to the Instances page in the ECS console and perform the following operations to create a snapshot for a disk:
You can also create a snapshot for a disk on the Disks page in the ECS console. To go to the Disks page, choose
in the left-side navigation pane.