Help Center > > User Guide> Instances> Modifying ECS vCPU and Memory Specifications> General Operations for Modifying Specifications

General Operations for Modifying Specifications

Updated at: Mar 23, 2021 GMT+08:00


If ECS specifications do not meet service requirements, you can modify the ECS specifications, including vCPUs and memory. Certain ECSs allow you to change their types when you modify their specifications.

  • Xen ECSs include S1, C1, C2, and M1 ECSs.
  • To obtain KVM ECSs, see the Virtualization Type column in ECS Specifications.


  • When modifying the specifications of an ECS, you are not allowed to select sold-out CPU and memory resources.
  • If ECS specifications are downgraded, the ECS performance will deteriorate.
  • Certain ECSs do not support specifications modification currently. For details about available ECS types as well as their functions and usage, see "Notes" in ECS Types.
  • When the disk status is Expanding, you are not allowed to modify the specifications of the ECS where the disk is attached.
  • Before modifying the specifications of a Windows ECS, modify the SAN policy by following the instructions provided in What Should I Do If a Disk Is Offline? to prevent disks disks from going offline after the specifications are modified.

Fees Description

Modifying specifications will lead to fee changes. For details, see Pricing of a Changed Specification.


After ECS specifications are modified, NIC flapping may occur. To prevent NIC flapping from affecting dependency configurations, perform the following operations before modifying the specifications:

  • Linux

    Run the following commands on the ECS to delete the files with persistent and net included in their names in the network rule directory:

    rm -fr /etc/udev/rules.d/*net*persistent*.rules

    rm -fr /etc/udev/rules.d/*persistent*net*.rules

  • Windows

    Delete the following directories in the registry on the ECS:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkList\Profiles

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkList\Signatures\Unmanaged

    Figure 1 Registry

Step 1: Modify Specifications

  1. Log in to the management console.
  2. Click in the upper left corner and select your region and project.
  3. Under Computing, click Elastic Cloud Server.
  4. Click More in the Operation column and select Modify Specifications.

    The Modify ECS Specifications page is displayed.

  5. Select the new ECS type, vCPUs, and memory as prompted.

    Before modifying the specifications, stop the ECS or select Automatically stop the ECSs and then modify specifications.

    Figure 2 Modifying specifications
  6. Click Next.
  7. Confirm the modified configuration. Read and select the service agreement, and then click Submit.
  8. Check whether the specifications have been modified.

    After modifying the specifications, you can check whether the specifications have been modified in Failures.

    1. Check whether Failures is displayed on the management console. For details, see Viewing Failures.
      • If yes, go to step 8.b.
      • If no, the specifications have been modified.
    2. Click Failures. Then, in the Failures dialog box, click Operation Failures and check whether the task is contained in the list by Name/ID, Operated At, or Task.
      • If yes, the specifications modification failed. See Follow-up Procedure for failure causes.
      • If no, the specifications have been modified.

Step 2: Check Disk Attachment

After specifications are modified, disk attachment may fail. Therefore, check disk attachment after specifications modification. If disks are properly attached, the specifications modification is successful.

Follow-up Procedure

Perform the following operations in the event of a specifications modification failure:

  1. Log in to the management console.
  2. Under Management & Deployment, click Cloud Trace Service.
  3. In the navigation pane on the left, choose Trace List.
  4. In the Trace Name column, locate the resizeServer event by resource ID.

    The resource ID is the ID of the ECS on which the specifications modification failed.

  5. Click View Trace in the Operation column to view the failure cause.

    If the fault cannot be rectified based on logs, contact customer service.

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