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

Prerequisites

Snapshots of the disk whose category you want to change are created. For more information, see Create a snapshot of a disk.

Background information

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

Before you change the category of a disk, take note of the following items:
  • Only the disk category change operations described in the following table are supported.
    Category of the original disk Description of supported category change
    Ultra disk You can convert ultra disks into standard SSDs, PL0 ESSDs, PL1 ESSDs, PL2 ESSDs, or PL3 ESSDs.
    Note You cannot convert ultra disks into standard SSDs in Hangzhou Zone D.
    Standard SSD You can convert standard SSDs into PL1, PL2, or PL3 ESSDs.
    ESSD PL0 You can convert PL0 ESSDs into PL1, PL2, or PL3 ESSDs.
    PL1, PL2, and PL3
    You can convert PL1, PL2, and PL3 ESSDs based on their billing methods.
    • If ESSDs use the pay-as-you-go billing method, you can convert the ESSDs between PL1, PL2, and PL3.
    • If ESSDs use the subscription billing method, you can upgrade the ESSDs only from the low performance level to the high performance level.
      • You can upgrade PL1 ESSDs to PL2 ESSDs.
      • You can upgrade PL1 ESSDs to PL3 ESSDs.
      • You can upgrade PL2 ESSDs to PL3 ESSDs.
    Note
    • Before you convert a disk on an Elastic Compute Service (ECS) instance into an ESSD, check whether the instance type supports ESSDs. For more information, see Instance family.

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

    • The performance levels to which ESSDs can be upgraded are determined based on their capacity. If you cannot select a higher performance level for an ESSD, 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 an extended period of 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. After you submit the request to change the category of a disk, we recommend that you view the change progress by going to the Task logs 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 Limits
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 concurrently performed within the same region and account.
  • You cannot change the category of a disk attached to an instance that is included in a migration plan.
During the category change The following limits apply while the category of a disk is being changed:
  • You cannot cancel the disk category change task after it is initiated.
  • You cannot create snapshots 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 the operating system of the instance.
After the category change The following limits apply after the category of a disk is changed:
  • If only the performance level of an ESSD is changed, you can change the ESSD category again at any time.
  • A disk can have its category changed only once within seven days.

Billing

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

  • After the category of a pay-as-you-go disk is changed, you are charged for the disk 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 EBS 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 and choose More > Change Category in the Actions column.
  5. In the Change Disk Category dialog box, set New Disk Category.
    Note After you convert a disk to an PL3 ESSD, you must attach the disk to an instance or restart the instance to which the disk is attached so that the PL3 ESSD can deliver optimal performance. Otherwise, the PL3 ESSD cannot deliver optimal performance but data reliability is not affected.
  6. Confirm the price and click OK.

Results

Use one of the following methods to view the change progress and the state 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.