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Changing the EVS Disk Type (Beta)

Scenarios

If the performance of an existing disk no longer meets your service requirements, you can change the disk type to improve the disk performance.

Constraints

Table 1 Constraints on the disk type change

Phase	Description
Before the change	You can only change the disk type when the disk status is Available or In-use. The disk type cannot be changed when any snapshot of the disk is being deleted. Changing the disk type may affect the disk performance, so change the type during off-peak hours. A disk having more than 128 snapshots cannot have its disk type changed. You can delete some snapshots and then change the disk type. The disk type of a disk protected by SDRS cannot be changed.
During the change	Some operations cannot be performed on the disk. Such operations include creating snapshots, creating backups, expanding the disk capacity, rolling back data from a snapshot, restoring data from a backup, attaching or detaching the disk, deleting the disk, transferring the disk, and creating an image from the ECS. Changing the disk type may take several hours or even longer, and cannot be stopped. The time depends on the throughput, storage space, and original disk type at the time of the change. In rare cases, the change may fail due to resource problems. In this case, you are advised to perform the change again. You can have a maximum of 10 disks with their types being changed at the same time. The OS cannot be changed if you are changing the disk type of a system disk.
After the change	In rare cases, the disk type may fail to be changed due to a background resource issue. If this happens, try again later.

The following table shows the supported changes between disk types.

Table 2 Supported changes between disk types

Source Disk Type	New Disk Type
General Purpose SSD V2	General Purpose SSD V2 (IOPS or throughput, or both changed), Ultra-high I/O, General Purpose SSD, or Extreme SSD
Extreme SSD	General Purpose SSD V2 (IOPS or throughput, or both changed), Ultra-high I/O or General Purpose SSD
Ultra-high I/O	General Purpose SSD V2 (IOPS or throughput, or both changed), Extreme SSD, or General Purpose SSD
General Purpose SSD	General Purpose SSD V2 (IOPS or throughput, or both changed), Extreme SSD or Ultra-high I/O
High I/O	General Purpose SSD V2 (IOPS or throughput, or both changed), Extreme SSD, Ultra-high I/O, or General Purpose SSD
Common I/O (end-of-sale)	General Purpose SSD V2 (IOPS or throughput, or both changed), Extreme SSD, Ultra-high I/O, General Purpose SSD, or High I/O

Impact on the System

Read and write operations on the disk are not affected.

Prerequisites

You are advised to create a snapshot for the disk to back up the disk data before changing the disk specifications. For details, see Creating an EVS Snapshot.

Procedure

1. Sign in to the console.
2. Click in the upper left corner and choose Storage > Elastic Volume Service.

   The Elastic Volume Service page is displayed.

3. In the disk list, locate the target disk, click More in the Operation column, and choose Modify Specifications.

   The Modify Specifications page is displayed.

4. Select a disk type from the drop-down list.
   Figure 1 Modify Specifications
   

5. Click Submit.

   The disk list is displayed, and the disk status is Changing disk type, indicating that the disk type is being changed. After the disk type changes to the target type, the operation is successful.