:Troubleshooting VNC remote connections to an instance

Default instance username and password

The default username depends on the operating system of the instance:

• For a Windows instance, the default username is Administrator.

• For a Linux instance, the default username is root or ecs-user.

The password is the one you set when you create the instance. For more information, see Create an instance by using the custom launch tab. If you forget your password, or if you choose to set it after the instance is created, you can reset it. For more information, see Reset the password of an instance.

Cannot log on to VNC with the instance password

If you cannot use your ECS instance password to log on to the instance using VNC, follow these steps to troubleshoot the issue.

1. Verify the login password.

   • Verify that you are using the correct username and password. For a Windows instance, the default username is Administrator. For a Linux instance, the default username is root or ecs-user.

   • Make sure that the password is in the correct case and that you have not copied any extra spaces or characters.

2. Reset the password.

   If you forget the password, you can reset it in the Alibaba Cloud Management Console. For more information, see Reset the password of an instance.

3. Restart the ECS instance.

   You can restart the ECS instance to resolve some temporary issues. For more information, see Restart an instance.

4. Check VNC logon permissions.

   If you are logging on as a RAM user, confirm that the RAM user has sufficient permissions to perform VNC logon operations. To connect to an instance using VNC, a RAM user requires at least the ecs:DescribeInstances and ecs:DescribeInstanceVncUrl permissions. For information about granting permissions to a RAM user, see Control the permissions of RAM users.

   {
     "Version": "1",
     "Statement": [
       {
         "Effect": "Allow",
         "Action": [
           "ecs:DescribeInstances",
           "ecs:DescribeInstanceVncUrl"
         ],
         "Resource": "*"
       }
     ]
   }

5. Log on to the instance through VNC again.

   For more information, see Connect to an instance by using the VNC management terminal.

VNC support for multiple concurrent users

No. Only one user can be logged in at a time.

Black screen on VNC connection

A black screen indicates that the system is in sleep mode. Follow the steps for your operating system:

• For a Linux instance, press any key to activate the instance and display the login screen.

• For a Windows instance, if the black screen persists, click Send Remote Commands > CTRL+ALT+DELETE in the upper-left corner of the page to display the login screen.

Resizing the VNC window

No. VNC does not support window resizing.

Inaccessible VNC management terminal

You can troubleshoot this issue from your browser. For example, in Google Chrome, press F12 to open Developer Tools and then analyze the information in the console.

VNC issues in Internet Explorer 8.0

The VNC management terminal supports only Internet Explorer 10 and later. Download the latest version of Internet Explorer.

We recommend that you use Google Chrome for better compatibility with the Alibaba Cloud Management Console.

"Secure Connection Failed" error in Firefox

This issue can occur if your version of Firefox does not share a common encryption algorithm with the VNC service.

We recommend that you use Google Chrome for better compatibility with the Alibaba Cloud Management Console.

Two cursors in a Windows VNC session

If two cursors appear after you log on to a Windows instance of the g7, c7, or r7 instance family using VNC, follow these steps to adjust the mouse settings:

1. Modify mouse settings in Control Panel.

   1. Open Control Panel, set View by to Small icons, and then click Mouse.

   2. In the Mouse Properties dialog box, click the Pointer Options tab, clear the Enhance pointer precision check box, and then click OK.

2. Modify mouse settings in the registry.

   Note

   If the double cursor issue does not occur on the user logon screen, you can skip this step.

   1. Open Registry Editor.

   2. In the navigation pane on the left, click HKEY_USERS. From the top menu bar, select Edit > Find.

   3. Search for MouseSpeed and click Find Next.

   4. Double-click the MouseSpeed entry, change the Value data to 0, and then click OK.

3. Log on to the Windows instance using VNC again. For more information, see Connect to an instance by using the VNC management terminal.

"Your account has expired" error on VNC logon

Alibaba Cloud Linux 3.2104 U11 (OpenAnolis Edition)
Kernel 5.10.134-18.al8.x86_64 on an x86_64
iZxxx login: root
Password:
Your account has expired  please contact your system administrator
User account has expired

sudo chage -M 99999 -E -1 root