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Elastic Compute Service

Passwords and key pairs

Resetting login password

Scenarios

If you have forgotten the login password for an instance, or did not specify a password when you create an instance, you can refer to this topic and select an appropriate method to specify the login password for one or more instances.

tip

Only Linux instances support SSH key pair-based login. Windows instances do not support this login method.

If a Linux instance is associated with an SSH key pair, after you reset the password, you can log in to the instance by using the password or the key pair.

Comparison of password reset methods

The following table describes the login password reset methods for instances. Select a suitable method based on your business requirements.

warning

If you first change the login password to A by using the offline reset method without restarting the instance, and then reset it to B by using the online reset method and restart the instance, the password that actually takes effect is A.

If you use a custom account and want to log in to your instance with a custom username, refer to Method 1 (Linux instances only) or Method 4.

Reset method	Recommended scenarios	Instance state	Installation of reset-authentication plug-in required	Installation of cloud assistant Agent required	Instance login required	Instance restart required	Batch operation supported
Method 1: Reset the instance login password online	You can reset the password for the root user or a custom user of Linux instances.	In service	No	Yes	Not required	Not required	Not supported
Method 2: Reset the instance login password offline	You can reset the password for the root user of Linux instances and the Administrator user of Windows instances.	Running or Stopped	Yes	Not required	Not required	Yes	Supported
Method 3: Use the cloud assistant to reset the password	For instances without the reset-authentication plug-in installed, we recommend that you use this method to reset the password.	In service	Not required	Yes	Not required	Not required	Supported
Method 4: Reset the password within an instance	Reset the password for a custom user.	In service	Not required	Not required	Yes	Not required	Not supported

Method 1: Reset the instance login password online

Limits

Limit item	Description
Cloud assistant Agent	To reset the password online, you need to install the cloud assistant Agent. Make sure that the cloud assistant Agent is running and that its version is not earlier than 1.11.1.
Instance state	The instance must be in the Running status.
Operating System	You cannot reset the login password online for Windows instances.
Batch operation	You cannot reset the password online for multiple instances at the same time.

Procedure

In the top menu bar, select the region and project of the target instance.

Click the "... > Instance property > Reset instance password" button in the "Actions" column on the right side of the target instance.

Select "Reset Password Online" as the reset method. Then enter the username (default: root) and the new password.

Click the "Reset" button and wait for the reset process to finish.

tip

During the reset process, a temporary key pair is generated by the cloud assistant to encrypt the password, ensuring the security of the password during transmission. The temporary key pair is automatically deleted after 60 seconds.

After you reset the password by using this method, you do not need to restart the instance. The new password takes effect immediately.

You can click the "Log in instance now" button and use the new password to log in to the instance.

(Optional) If the operation fails, you can go to the cloud assistant management page to view task details. Learn more.

Method 2: Reset the instance login password offline

Usage notes

Type	Description
Instance related	The instance status must be Running or Stopped.
		After you reset the password, you need to restart the instance for the new password to take effect.
		A newly created instance must run for several minutes before you can reset the password offline. Attempting to reset the password immediately after creation results in an error.
Image-related	For Windows instances, take note of the following items. Otherwise, the reset fails. Proceed with caution. Before you reset the password, do not frequently start up or shut down the target instances. After you reset the password and restart the instances, we recommend that you do not restart or shut down any Running instance again within 10 minutes.
Image-related		Before you reset the password for an instance created by using a custom image, you need to install the reset-authentication plug-in. Otherwise, the reset fails.
Batch operation	When you reset the password offline for multiple instances at the same time, you can select up to 100 instances at a time. If password reset submission fails for any instance in the batch, the batch operation cannot be performed. Follow the onscreen instructions to complete the required steps and try again, or select individual instances to reset their passwords separately.

Procedure

In the top menu bar, select the region and project of the target instance.

On the Instances page, use one of the following methods to go to the password reset page.

Reset the password for a single instance: In the "Actions" column to the right of the target instance, click "... > Instance property > Reset instance password".

Reset the password for multiple instances at the same time: Select one or more instances for which you want to reset the password, and click "... > Reset instance password".

Select "Reset Password Offline" as the reset method and enter the new password.

Select "Agree to restart Instances now" to make the operation take effect. You can also manually restart the instances after the operation is complete.

tip

If you select "Agree to restart Instances now", your business is interrupted. Proceed with caution.

After selecting immediate restart, the Running ECS instances will restart by default, and the Stopped ECS instances will start by default.

Click "Confirm" to complete the procedure.

(Optional) After the instance restarts, you can use the new password to log in to the instances.

Method 3: Use the cloud assistant to reset the password

For information about how to use the cloud assistant to reset the login password for instances, see Modifying login passwords for multiple instances at the same time/Adding SSH public key.

Method 4: Reset the password within an instance

For information about how to reset the login password for a custom account within an instance, see Logging in to ECS instance with custom account.