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Elastic Compute Service:ECS instance configuration change overview

Last Updated:Jun 23, 2026

Change the instance type, public bandwidth, or disk billing method of an ECS instance to match your workload.

Change the instance type

An instance type is a predefined combination of vCPUs and memory. You cannot change vCPUs or memory individually.

Note

Before you change the instance type, check the compatible instance types on the configuration change page.

The available method depends on the billing method of the instance.

Billing method

Operating Period

Effective time

Related operations

Subscription

Before the instance expires

After the instance is restarted

Within 15 days before the instance expires

For the change to take effect, you must restart the instance within 7 days after the new billing cycle starts.

Downgrade the configurations of an instance during renewal

Pay-as-you-go

N/A

After the instance is restarted

Change pay-as-you-go instance type

Change the billing method for network usage

The available method depends on the public IP address type.

Public IP address type

Effective time

Related operations

System-assigned public IP address

Immediately

Change the billing method for network usage

Elastic IP address (EIP)

Immediately

Modify the bandwidth of an EIP

Modify the maximum public bandwidth

The available method depends on the public IP address type and the billing method of the instance.

Important
  • If you change the public bandwidth from a non-zero value to 0 Mbit/s, the public IP address is immediately released.

  • If you change the public bandwidth from 0 Mbit/s to a non-zero value, the system assigns a public IP address to the instance.

Public IP address type

Applicable scope

Effective time

Reference

System-assigned public IP address

Modify the base public bandwidth of a subscription instance

Immediately

Modify the bandwidth configurations of subscription instances

Modify the base public bandwidth of a subscription instance during renewal

After the new billing cycle starts

Downgrade the configurations of an instance during renewal

Modify the base public bandwidth of a pay-as-you-go instance

Immediately

Modify for pay-as-you-go instance

EIP

Modify the bandwidth of an EIP for a subscription or pay-as-you-go instance

Immediately

Modify the bandwidth of an EIP

Change the billing methods of data disks

Only subscription instances support changing the billing method of data disks, because pay-as-you-go instances accept only pay-as-you-go data disks.

Change time

Effective time

Related operations

Before the instance expires

Immediately

Change the billing method of a disk

Within 15 days before expiration, or after expiration but before release

Immediately

Downgrade the configurations of an instance during renewal

FAQ

How are the fees for upgrading an ECS instance calculated?

  • For subscription instances, the upgrade fee is the price difference between the new and original configurations for the remaining subscription period.

  • For pay-as-you-go instances, billing starts at the new instance type rate after the upgrade.

The actual fee is displayed on the upgrade page. You can also check the Expenses and Costs page for details.

Does upgrading or downgrading an ECS instance affect business operations?

It might. The platform guarantees only that the instance can start with the new resources. Before you change the configuration, verify that the target CPU, memory, network, and storage performance meet your workload requirements to avoid startup failures.

What impact does upgrading or downgrading an ECS instance have on the services on the instance?

Upgrading or downgrading an instance causes a brief service interruption. Perform the operation during off-peak hours and back up your data in advance.

  • Pay-as-you-go instances: Stop the instance before changing its configuration.

  • Subscription instances: Restart the instance for the new configuration to take effect.

If any of the following conditions apply, create snapshots or images before the operation:

  • Stateful services: Perform a primary/secondary switchover or schedule a maintenance window in advance.

  • Custom images: Verify the compatibility between the target instance type and the current operating system. See Check OS compatibility.

  • Cross-generation upgrades (for example, from generation 7 to 8): NVMe disk device names may change. Check for conflicts in fstab or startup scripts. See Device names of NVMe disks.

Can I cancel an upgrade order to restore the original configuration?

No. After an upgrade order takes effect, it cannot be canceled. To restore the original configurations, downgrade the instance. You are charged for the downgrade.

See Instance FAQ.