If you want to use data stored on an existing or accidentally released disk to perform data extraction or fault analysis, you can use a snapshot of the disk to create disks. You can create disks from snapshots of system disks or data disks.

Prerequisites

A snapshot is created from a system disk or data disk. The snapshot ID is obtained. For more information, see Create a normal snapshot.

Background information

When you create a disk from a snapshot, take note of the following items:
  • Disks are independent of each other and cannot be merged by formatting. Therefore, we recommend that you determine the number and capacity of disks that you need before you create them.
  • We recommend that you do not use Logical Volume Manager (LVM) to create logical volumes on multiple disks. This is because a snapshot can only back up data of a single disk. If you create a logical volume on multiple disks by using LVM, data discrepancies may occur when you roll back these disks.

Procedure

  1. Log on to the ECS console.
  2. In the left-side navigation pane, choose Storage & Snapshots > Disks.
  3. In the upper-right corner of the Disks page, click Create Disk.
  4. On the disk creation page, click Create from Snapshot and select a snapshot from which you want to create disks.
  5. Configure other parameters for the disks.
    Parameter Description
    Attach Specify whether to attach the created disks to ECS instances.
    • Not Attach: only creates disks and does not attach the disks to ECS instances.

      If you select this option, only pay-as-you-go disks can be created. The disks and the ECS instances to which you want to attach the disks must reside within the same zone. Proceed with caution when you specify Region.

    • Attach to ECS Instance: creates disks and attaches the disks to the specified ECS instance.

      If you select this option, you must specify ECS Instance by selecting a destination region and an ECS instance.

    Billing Method Specify the billing method of the disks.
    • Pay-As-You-Go: Pay-as-you-go disks can be attached to subscription or pay-as-you-go instances.
    • Subscription: Subscription disks must be attached to subscription instances.
    Storage Select a disk category and specify the disk capacity.
    The following section describes the disk capacities corresponding to different snapshot types:
    • Normal snapshot: supports a disk capacity of at least the same size as the snapshot.

      If the disk capacity that you set is greater than the snapshot size, you must re-partition the disk to ensure that the excess disk capacity can be used.

      Notice If the snapshot size is less than 2,048 GiB and you want to set the disk capacity to a value greater than 2,048 GiB, make sure that the source disk of the snapshot uses the GUID Partition Table (GPT) partition format. If the source disk does not use GPT, we recommend that you set the disk capacity to a value less than 2,048 GiB to avoid data loss during partitioning. For more information, see Partition and format a data disk larger than 2 TiB.
    • Local snapshot: supports only a capacity equal to the snapshot size.

    The following section describes other information:

    • Performance Level: You can set performance levels only for enhanced SSDs (ESSDs). You can select a performance level based on the capacity of an ESSD. The disk performance varies with the capacity of the ESSD and the performance level. For more information, see Enhanced SSDs.
    • Disk Encryption: Disk encryption is suitable for scenarios that require data security and regulatory compliance. If you select this option, data stored on the disk is automatically encrypted.
    Quantity Select the number of disks that you want to create.
    Note
    • You can attach a maximum of 16 data disks to an ECS instance. When you purchase disks, take note of the number of data disks on the instance to which you want to attach the disks.
    • Pay-as-you-go disks have capacity quotas. The total capacity that you purchase cannot exceed the capacity quota. You can use the following formula to calculate the total disk capacity: Total capacity = Capacity of a single disk × Number of disks. After you configure the disk category, the purchased capacity and the remaining capacity are displayed on the disk creation page.
    Release Specify whether to release automatic snapshots of the disks along with them or release the disks along with the instance to which they are attached. This parameter is available only when you select Attach to ECS Instance.
    Terms of Service Read and select ECS Terms of Service.
    Others (Optional) Specify the disk name, description, tags, and resource group for easy management.
  6. Confirm the configuration information and disk fees, and then click Preview.
  7. In the Preview dialog box, confirm the purchase information and click Create.
    After the disks are created, you can view the created disks on the Disks page. However, you cannot use the disks on ECS instances. If you want to use the disks, you must perform subsequent operations.

What to do next

If you want to use the created disks, you must perform the following operations.
Scenario What to do next
If you select Attach to ECS Instance when you create the disks
  • Windows: No operations are required.
  • Linux: Log on to the instance and run the following command to perform the mount operation:
    mount <Disk partition> <Mount point>
If you select Not Attach when you create the disks