Updated on 2026-07-07 GMT+08:00

Creating a Disk from a Snapshot

Scenarios

When you create a disk from a snapshot, the new disk contains the same data as the snapshot. This enables you to copy data between disks within the same AZ or across AZs for purposes such as environment cloning or data backup. This section describes how to create a new data disk from a snapshot.

Constraints

Table 1 Constraints

Item

Description

Legacy snapshots

  • Batch disk creation from a snapshot is not supported.
  • A disk created from a snapshot has the same device type (SCSI or VBD), encryption attribute, AZ, region, and disk type as the snapshot's source disk.
  • A snapshot whose name starts with autobk_snapshot_vbs_, manualbk_snapshot_vbs_, autobk_snapshot_csbs_, or manualbk_snapshot_csbs_ is automatically generated during backup. Such a snapshot can only be viewed. It cannot be used to create new disks.

Standard snapshots

  • A standard snapshot with Instant Snapshot Restore disabled can only be used to create disks when the snapshot status is Available.
  • If Instant Snapshot Restore is enabled for a standard snapshot, when its upload is in progress, you can use it to create a disk but cannot change the device type (SCSI or VBD), encryption attribute, AZ, and type of the new disk. They are kept the same as those of the snapshot's source disk.
  • You can use a standard snapshot to batch create disks after its data upload is complete.
  • After a standard snapshot has been uploaded, you can change the device type (SCSI or VBD), encryption attribute, AZ, or type of the disks when using this snapshot to create disks on the console or through the V5 version API. Snapshots created using the V2 version API cannot be used across AZs.

General constraints

  • When you create a disk from a snapshot, the disk capacity must be greater than or equal to the snapshot size. In the condition that you do not specify a disk capacity, if the snapshot size is smaller than 10 GiB, the default capacity 10 GiB will be used as the disk capacity; if the snapshot size is greater than 10 GiB, the snapshot size will be used as the disk capacity.

You can view the snapshot upload progress in the status column. If there is a progress bar, the upload is still in progress. After the progress bar disappears, the upload is complete.

Follow-Up Operations

A disk created from a snapshot already has partitions and file systems. You need to attach the disk to an ECS and then mount the partitions before you can use the disk.
  • If you choose not to attach the disk to a server during creation, attach it to an ECS by referring to Attaching an EVS Disk before using it.
  • If you choose to use existing partitions instead of re-initializing the disk, mount the partitions in the OS.
  • If you choose to re-initialize the disk, do as follows:

    Note that re-partitioning a disk will erase all the existing data on the disk, so you are advised to use snapshots to back up the disk data first.

    • In Linux, unmount the partitions, delete them (by running fdisk <disk-name>, entering d and the partition number, and entering w), and then re-initialize the disk.
    • In Windows, delete the partitions (using the volume deletion tool) and then re-initialize the disk.

    For details about how to initialize a disk, see Initializing EVS Data Disks.

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