Alibaba Cloud offers different categories of disks to suit the storage and cost performance requirements of different scenarios. You can change the categories of your disks based on your needs. For example, assume that you have a standard SSD and you want it to deliver a higher IOPS. You can convert this standard SSD into an enhanced SSD (ESSD).

Prerequisites

Before you change the category of a disk, we recommend that you create a disk snapshot. For more information, see Create a snapshot for a disk.

Background information

For more information about the performance of different disk categories, see EBS performance.

When you change the category of a disk, take note of the following items:
  • Only the following disk category change operations are supported. Other operations such as disk category downgrades are not supported.
    • You can convert ultra disks into standard SSDs, PL0 ESSDs, PL1 ESSDs, PL2 ESSDs, or PL3 ESSDs. PL0 ESSDs, PL1 ESSDs, PL2 ESSDs, and PL3 ESSDs refer to ESSDs at performance levels 0, 1, 2, and 3.
      Note You cannot convert ultra disks into standard SSDs in the following zones:
      • China (Qingdao): Zone B
      • China (Beijing): Zone B, Zone D, and Zone E
      • China (Hangzhou): Zone B, Zone D, Zone E, and Zone F
      • China (Shanghai): Zone A and Zone C
      • China (Shenzhen): Zone B and Zone C
      • UAE (Dubai): Zone A
      • Australia (Sydney): Zone A
    • You can convert standard SSDs into PL1 ESSDs, PL2 ESSDs, or PL3 ESSDs.
    • The disk category of PL0 ESSDs cannot be changed. You can upgrade or downgrade pay-as-you-go ESSDs among performance levels 1, 2, and 3, but you can only upgrade the performance levels of subscription PL1 ESSDs, PL2 ESSDs, or PL3 ESSDs.
    Note
    • Before you convert a disk on an instance into an ESSD, check whether the instance type supports ESSDs. For more information, see Instance families.

      If the instance type does not support ESSDs, upgrade the instance type to support ESSDs and then convert the disk. For more information, see Instance families that support instance type changes.

    • You can select a new performance level for an ESSD based on the capacity of the ESSD. If the capacity of an ESSD is too small to upgrade its performance level, resize the ESSD and then upgrade its performance level. For more information, see Overview.
  • When you change the category of a disk, the performance of the disk may also change. We recommend that you change the categories of your disks during off-peak hours.
  • It may take a long time to change the category of a disk. The amount of time required is determined based on the storage capacity, original category, and throughput of the disk during the change. After you submit the request to change the category of a disk, we recommend that you view the change progress by going to the Tasks page in the ECS console or by calling the DescribeTaskAttribute operation.
  • Disk categories may fail to change if resources are insufficient. If a failure occurs, try again later.

Limits

Phase Limit
Before the category change Before you change the category of a disk, make sure that the following requirements are met:
  • Up to five disk category change tasks can be performed concurrently within the same region and account.
  • You cannot change the category of a disk that has expired or that is being migrated.
During the category change The following limits apply when the category of a disk is being changed:
  • The disk category change task cannot be canceled after it is initiated.
  • Snapshots cannot be created for the disk.
  • You cannot resize the disk.
  • You cannot partition or format the disk.
  • You cannot re-initialize the disk.
  • You cannot roll back the disk by using snapshots.
  • You cannot attach the disk to an instance or detach it from an instance.
  • If the disk is an ESSD, you cannot change its performance level.
  • If the disk is a system disk, you cannot replace it.
After the category change A disk can have its category changed only once within seven days.

Billing

After the category of a disk is changed, the following changes occur to the billing of the disk:

  • After the category of a pay-as-you-go disk is changed, the disk is billed based on the new disk category.
  • After the category of a subscription disk is changed, the price difference is calculated based on the remaining subscription duration and the new disk category. You must pay for the difference.

For information about disk pricing, see Elastic Block Storage devices.

Procedure

  1. Log on to the ECS console.
  2. In the left-side navigation pane, choose Storage & Snapshots > Disks.
  3. In the top navigation bar, select a region.
  4. Find the disk whose category you want to change. Choose More > Change Category in the Actions column.
  5. In the Change Disk Category dialog box, set Category after Change and confirm the price.
  6. Click OK.

Results

Use one of the following methods to view the change progress and the status of the disk:
  • Method 1: Go back to the Disks page and view the category of the disk in the Disk Category column.
  • Method 2: In the left-side navigation pane, choose Maintenance & Monitoring > Tasks. Find the change task and view the change progress in the Status column.