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

Prerequisites

  • A snapshot is created for a system or data disk. The snapshot ID is obtained. For more information, see Create a snapshot.
  • The disks created in this example are billed on a pay-as-you-go basis. For more information about how to create a subscription disk, see Create a subscription disk.
    Note You can also create disks from snapshots when you create an ECS instance. The disks have the same billing method as the instance.

Background information

Take note of the following items when you create a disk from a snapshot:
  • You cannot merge multiple disks by formatting them because they are independent of each other. 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 will 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, perform the following operations:
    1. Select a region and a zone.
      If you want to attach the disk to an ECS instance, the disk and the instance must reside within the same region and zone.
    2. Configure the disk category, capacity, quantity, and name.

      The following table describes some parameters on the disk creation page.

      Parameter Description Reference
      Disk category Supports enhanced SSDs (ESSDs), standard SSDs, and ultra disks. Disk overview
      Capacity The following section describes disk capacities of different snapshot types:
      • Normal snapshot: supports a disk capacity that is at least the snapshot size. If the disk capacity that you set is greater than the snapshot size, you must re-partition the disk to ensure that you can use the excess capacity.
        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, ensure that the source disk of 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 that may occur during partitioning. For more information, see Partition and format data disks larger than 2 TiB.
      • Local snapshot: supports only a capacity equal to the snapshot size.
      Snapshot overview
      Performance Level You can set performance levels for ESSDs based on their configured capacity. The performance levels include PL1, PL2, and PL3.
      Note You can set performance levels only for ESSDs.
      Enhanced SSDs
      Create from Snapshot Click Create from Snapshot and select a snapshot a system or data disk. N/A
      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. Encryption overview
      Disk Backup If you select this option, the automatic snapshot policy is executed and data stored on the disk is backed up on a regular basis. Overview
      Quantity The total number of pay-as-you-go data disks that you create under your account in a region cannot be greater than five times the total number of pay-as-you-go instances under your account in that region. Limits
    3. Bind one or more tags to the disk.
    4. Add the disk to a resource group.
    5. Select ECS Terms of Service.
    6. Confirm the configuration and Total fees, and click Preview. Then, follow the tips to create the disk.

Result

After the disk is created, go back to the Disks page and refresh the disk list. Find the new disk. Unattached is displayed in the Status column corresponding to the disk.

What to do next

The disk can be used only after it is attached to an ECS instance. For a Linux instance, you must log on to the instance and run the mount command to mount the disk. For more information, see Attach a data disk.