- Tutorial
- Release Notes and Announcements
- Release Notes
- Public Image Release Notes
- Announcements
- Temporary Solution for the Windows Blue Screen Issue Caused by CrowdStrike Security Software on July 19, 2024
- Announcement on Flexible Discounts for Spot Instances in Some Regions
- Updating Some Image Pip Package Management Tools for CentOS 7
- CentOS 8 End of Maintenance
- Discontinuation of Support for SUSE Commercial Images
- Price Reduction in Selected Availability Zones
- OrcaTerm Proxy IP Addresses Updates
- Pay-as-you-go Price Adjustments for Standard S3 CVMs in the Silicon Valley Region
- Vulnerability repairing for Linux images
- Stopping supporting for Ubuntu 10.04 images
- Solution to Tomcat Start Failure on Ubuntu14.04
- Upgrading Virtio network card drive for Windows CVMs
- About Configuration of Security Group Port 53
- Windows Server 2003 System Images End of Support Announcement
- End of Support for Windows Server 2008 R2 Enterprise Edition SP1 64-bit System Images
- Product Introduction
- Purchase Guide
- Getting Started
- Operation Guide
- Operation Guide Overview
- Use Limits
- Convenience Features
- Instances
- Creating Instances
- Managing Instance Launch Template
- Batch Sequential Naming or Pattern String-Based Naming
- Logging In to Linux Instances
- Logging in to Windows instance
- Adjusting Configuration
- View Instance Details
- Renaming Instances
- Resetting Instance Password
- Managing Instance IPs
- Changing Security Group
- Conversion from Pay-As-You-Go to Monthly Subscription
- Searching for Instances
- Exporting Instance List
- Renewing Instances
- Starting Up Instances
- Shutting Down Instances
- Restarting Instances
- Reinstalling System
- Using Tencent Cloud Automation Tools to execute commands
- Terminating/Returning Instances
- Enabling Instance Termination Protection
- Instance Repossession or Recovering
- Spot Instances
- Querying the Repossession Status of a Spot Instance
- No Charges When Shut Down for Pay-as-You-Go Instances
- Managing Roles
- Enabling and Disabling Hyper-Threading
- Reserved Instances
- Images
- Migrating Servers
- Maintenance Tasks
- Cloud Disks
- Networking
- Security
- Security Groups
- Protection of Sensitive Operations
- Managing Login Password
- Managing SSH Keys
- Spread Placement Group
- Unblocking Port 25
- Tags
- Monitoring and Alarms
- Sample Console Configuration
- Practical Tutorial
- Best Practices
- Choosing the CVM Model
- Setting up a Website
- Building an Environment
- Building a Website
- Building an Application
- Sending Emails through Port 465
- Building a Visual GUI
- Data Backup
- Uploading Local Files to CVM
- Copying Local Files to CVMs
- Uploading Files from Windows to a Windows CVM via MSTSC
- Uploading Files from MacOS to Windows CVM Using MRD
- Uploading Files from Linux to Windows CVM using RDP
- Uploading files via WinSCP to a Linux CVM from Windows
- Uploading Files from Linux or MacOS to Linux CVM via SCP
- Uploading Files from Linux to a CVM Using FTP
- Uploading Files from Windows to a CVM Using FTP
- Other CVM Operations
- CVM Access to COS via a Private Network
- Best Practices for Boot Mode Legacy BIOS and UEFI
- Recovering Data on Linux CVMs
- Managing Disk Space on Windows CVMs
- Changing Kernel of a Linux Instance Manually
- Setting Up Windows-based AD Domain on a CVM
- Network Performance Test
- High-throughput Network Performance Test
- Using USB/IP to Share USB Devices in Linux
- Using RemoteFx to Redirect USB Devices in Windows
- Using AVX-512 Instructions to Accelerate AI Applications on CVM
- Building Tencent SGX Confidential Computing Environment
- Configuring Persistent Memory in M6p Instances
- Calling Cloud APIs via Python to Share Custom Images in Batches
- Operations Guide
- Initializing Data Disks
- Environment Configurations
- Installing Software
- User Data
- Work with Operating Systems
- System Activation
- System Updates
- System Shutdown
- Configuring High-performance Power Management
- Windows Recovery Mode
- Updating the Virtio ENI Driver
- Modifying SID
- Modifying VNC Resolution
- Ensuring Unique SIDs for CVMs Using Sysprep
- Use of the atop Monitoring Tools by Linux Instances
- Introduction to Linux Kernel Parameters
- Others
- Troubleshooting
- Instance-Related Failures
- CVM Login Failures
- Windows Instance Login Failures
- Windows Instance Login Failures
- An authentication error occurred when you tried to log in to a Windows instance remotely
- Failed to Reset the CVM Password or the CVM Password Is Invalid
- Connection to a Windows CVM through Remote Desktop was denied
- Requires network-level identity verification
- Problems occurred when you tried to log in to a Windows CVM remotely on Mac
- Failed to log in to a Windows CVM due to high CPU and memory usage
- Failed to connect to a remote computer through Remote Desktop
- Credentials Not Work
- Windows instance: no remote Desktop license server can provide license
- Remote Login Failure Due To Port Issues
- Linux Instance Login Failures
- Linux Instance Login Failures
- Unable to Log in to a Linux Instance via SSH Key
- Failing to log in to a Linux CVM due to high CPU and memory usage
- Remote Login Failure due to Port Issues
- VNC Login Error (Module is Unknown)
- VNC Login Error (Account Locked due to XXX Failed Logins)
- VNC Login Error (Login Failed with Correct Password)
- VNC or SSH Login Error (Permission Denied)
- Login Failure Due to /etc/fstab Configuration Errors
- sshd Configuration File Permissions
- Infinite Loop Call in /etc/profile
- Login Failure Due to Server Isolation
- Login Failure Due to High Bandwidth Occupation
- Remote Connect Failure Due to Security Group Settings
- Troubleshooting Linux Instance Issues via VNC and Rescue Mode
- Failed to shut down or restart a CVM
- Network Namespace Creation Failure
- Kernel and IO Issues
- Missing System bin or lib Soft Link
- Suspected Infection with Virus
- "no space left on device" Error During File Creation
- Linux CVM Memory Issues
- Network Related Failures
- Instance-Related Failures
- API Documentation
- History
- Introduction
- API Category
- Region APIs
- Instance APIs
- RunInstances
- DescribeInstances
- DescribeInstanceFamilyConfigs
- DescribeInstancesOperationLimit
- InquiryPriceRunInstances
- InquiryPriceResetInstance
- InquiryPriceResetInstancesType
- StartInstances
- RebootInstances
- StopInstances
- ResizeInstanceDisks
- ResetInstancesPassword
- ModifyInstancesAttribute
- EnterRescueMode
- ExitRescueMode
- InquirePricePurchaseReservedInstancesOffering
- InquiryPriceResizeInstanceDisks
- TerminateInstances
- ModifyInstancesProject
- ResetInstancesType
- DescribeInstancesStatus
- DescribeReservedInstancesConfigInfos
- DescribeZoneInstanceConfigInfos
- PurchaseReservedInstancesOffering
- ResetInstance
- DescribeInstanceTypeConfigs
- DescribeInstanceVncUrl
- Cloud Hosting Cluster APIs
- Image APIs
- Instance Launch Template APIs
- Making API Requests
- Placement Group APIs
- Key APIs
- Security Group APIs
- Network APIs
- Data Types
- Error Codes
- FAQs
- Related Agreement
- Glossary
- Tutorial
- Release Notes and Announcements
- Release Notes
- Public Image Release Notes
- Announcements
- Temporary Solution for the Windows Blue Screen Issue Caused by CrowdStrike Security Software on July 19, 2024
- Announcement on Flexible Discounts for Spot Instances in Some Regions
- Updating Some Image Pip Package Management Tools for CentOS 7
- CentOS 8 End of Maintenance
- Discontinuation of Support for SUSE Commercial Images
- Price Reduction in Selected Availability Zones
- OrcaTerm Proxy IP Addresses Updates
- Pay-as-you-go Price Adjustments for Standard S3 CVMs in the Silicon Valley Region
- Vulnerability repairing for Linux images
- Stopping supporting for Ubuntu 10.04 images
- Solution to Tomcat Start Failure on Ubuntu14.04
- Upgrading Virtio network card drive for Windows CVMs
- About Configuration of Security Group Port 53
- Windows Server 2003 System Images End of Support Announcement
- End of Support for Windows Server 2008 R2 Enterprise Edition SP1 64-bit System Images
- Product Introduction
- Purchase Guide
- Getting Started
- Operation Guide
- Operation Guide Overview
- Use Limits
- Convenience Features
- Instances
- Creating Instances
- Managing Instance Launch Template
- Batch Sequential Naming or Pattern String-Based Naming
- Logging In to Linux Instances
- Logging in to Windows instance
- Adjusting Configuration
- View Instance Details
- Renaming Instances
- Resetting Instance Password
- Managing Instance IPs
- Changing Security Group
- Conversion from Pay-As-You-Go to Monthly Subscription
- Searching for Instances
- Exporting Instance List
- Renewing Instances
- Starting Up Instances
- Shutting Down Instances
- Restarting Instances
- Reinstalling System
- Using Tencent Cloud Automation Tools to execute commands
- Terminating/Returning Instances
- Enabling Instance Termination Protection
- Instance Repossession or Recovering
- Spot Instances
- Querying the Repossession Status of a Spot Instance
- No Charges When Shut Down for Pay-as-You-Go Instances
- Managing Roles
- Enabling and Disabling Hyper-Threading
- Reserved Instances
- Images
- Migrating Servers
- Maintenance Tasks
- Cloud Disks
- Networking
- Security
- Security Groups
- Protection of Sensitive Operations
- Managing Login Password
- Managing SSH Keys
- Spread Placement Group
- Unblocking Port 25
- Tags
- Monitoring and Alarms
- Sample Console Configuration
- Practical Tutorial
- Best Practices
- Choosing the CVM Model
- Setting up a Website
- Building an Environment
- Building a Website
- Building an Application
- Sending Emails through Port 465
- Building a Visual GUI
- Data Backup
- Uploading Local Files to CVM
- Copying Local Files to CVMs
- Uploading Files from Windows to a Windows CVM via MSTSC
- Uploading Files from MacOS to Windows CVM Using MRD
- Uploading Files from Linux to Windows CVM using RDP
- Uploading files via WinSCP to a Linux CVM from Windows
- Uploading Files from Linux or MacOS to Linux CVM via SCP
- Uploading Files from Linux to a CVM Using FTP
- Uploading Files from Windows to a CVM Using FTP
- Other CVM Operations
- CVM Access to COS via a Private Network
- Best Practices for Boot Mode Legacy BIOS and UEFI
- Recovering Data on Linux CVMs
- Managing Disk Space on Windows CVMs
- Changing Kernel of a Linux Instance Manually
- Setting Up Windows-based AD Domain on a CVM
- Network Performance Test
- High-throughput Network Performance Test
- Using USB/IP to Share USB Devices in Linux
- Using RemoteFx to Redirect USB Devices in Windows
- Using AVX-512 Instructions to Accelerate AI Applications on CVM
- Building Tencent SGX Confidential Computing Environment
- Configuring Persistent Memory in M6p Instances
- Calling Cloud APIs via Python to Share Custom Images in Batches
- Operations Guide
- Initializing Data Disks
- Environment Configurations
- Installing Software
- User Data
- Work with Operating Systems
- System Activation
- System Updates
- System Shutdown
- Configuring High-performance Power Management
- Windows Recovery Mode
- Updating the Virtio ENI Driver
- Modifying SID
- Modifying VNC Resolution
- Ensuring Unique SIDs for CVMs Using Sysprep
- Use of the atop Monitoring Tools by Linux Instances
- Introduction to Linux Kernel Parameters
- Others
- Troubleshooting
- Instance-Related Failures
- CVM Login Failures
- Windows Instance Login Failures
- Windows Instance Login Failures
- An authentication error occurred when you tried to log in to a Windows instance remotely
- Failed to Reset the CVM Password or the CVM Password Is Invalid
- Connection to a Windows CVM through Remote Desktop was denied
- Requires network-level identity verification
- Problems occurred when you tried to log in to a Windows CVM remotely on Mac
- Failed to log in to a Windows CVM due to high CPU and memory usage
- Failed to connect to a remote computer through Remote Desktop
- Credentials Not Work
- Windows instance: no remote Desktop license server can provide license
- Remote Login Failure Due To Port Issues
- Linux Instance Login Failures
- Linux Instance Login Failures
- Unable to Log in to a Linux Instance via SSH Key
- Failing to log in to a Linux CVM due to high CPU and memory usage
- Remote Login Failure due to Port Issues
- VNC Login Error (Module is Unknown)
- VNC Login Error (Account Locked due to XXX Failed Logins)
- VNC Login Error (Login Failed with Correct Password)
- VNC or SSH Login Error (Permission Denied)
- Login Failure Due to /etc/fstab Configuration Errors
- sshd Configuration File Permissions
- Infinite Loop Call in /etc/profile
- Login Failure Due to Server Isolation
- Login Failure Due to High Bandwidth Occupation
- Remote Connect Failure Due to Security Group Settings
- Troubleshooting Linux Instance Issues via VNC and Rescue Mode
- Failed to shut down or restart a CVM
- Network Namespace Creation Failure
- Kernel and IO Issues
- Missing System bin or lib Soft Link
- Suspected Infection with Virus
- "no space left on device" Error During File Creation
- Linux CVM Memory Issues
- Network Related Failures
- Instance-Related Failures
- API Documentation
- History
- Introduction
- API Category
- Region APIs
- Instance APIs
- RunInstances
- DescribeInstances
- DescribeInstanceFamilyConfigs
- DescribeInstancesOperationLimit
- InquiryPriceRunInstances
- InquiryPriceResetInstance
- InquiryPriceResetInstancesType
- StartInstances
- RebootInstances
- StopInstances
- ResizeInstanceDisks
- ResetInstancesPassword
- ModifyInstancesAttribute
- EnterRescueMode
- ExitRescueMode
- InquirePricePurchaseReservedInstancesOffering
- InquiryPriceResizeInstanceDisks
- TerminateInstances
- ModifyInstancesProject
- ResetInstancesType
- DescribeInstancesStatus
- DescribeReservedInstancesConfigInfos
- DescribeZoneInstanceConfigInfos
- PurchaseReservedInstancesOffering
- ResetInstance
- DescribeInstanceTypeConfigs
- DescribeInstanceVncUrl
- Cloud Hosting Cluster APIs
- Image APIs
- Instance Launch Template APIs
- Making API Requests
- Placement Group APIs
- Key APIs
- Security Group APIs
- Network APIs
- Data Types
- Error Codes
- FAQs
- Related Agreement
- Glossary
Overview
This document introduces how to adjust the resolution of the instance login via VNC through the CVM console.
If Windows system images have very low VNC resolutions, some applications may fail to be properly displayed or opened. To avoid these issues, you need to modify the resolutions of Windows system images.
Some Linux system images have lower VNC display resolutions by default. For example, the VNC resolution for CentOS is only 720 * 400. You can set the VNC resolution to 1024 * 768 by modifying the parameter
grub.Note:
More recent Linux images such as CentOS 7, CentOS 8, Ubuntu, and Debian 9.0 adopt a default VNC resolution of 1024 * 768, which can be used without any modifications.
Prerequisites
You have logged in to the instance via VNC. For details, see the following documents:
Directions
Note:
The steps below describe how to modify the VNC resolution of a Windows instance on the Windows Server 2012 operating system.
1. Right-click on the desktop and select Screen resolution, as shown below:
2. In the “Screen Resolution” window, set Resolution to your desired value and click Apply, as shown below:
3. In the pop-up window, click Keep changes.
4. Click OK to close the “Screen Resolution” window.
The steps below describe how to modify the VNC resolution of a Linux instance on the CentOS 6 and Debian 7.8 operating systems.
CentOS 6
A CentOS 6 image has a VNC resolution of 720 * 400 by default. To set its resolution to 1024 * 768, modify the launch parameter
grub as follows:1. Run the following command to open the
/etc/grub.conf file.vi /etc/grub.conf
2. Press i to switch to the editing mode, and add 
vga=792 to the parameter grub, as shown below:
3. Click Esc and enter :wq to save and close the file.
4. Run the following command to restart the CVM.
reboot
Debian 7.8
Both Debian 7.8 and Debian 8.2 images have VNC resolutions of 720 * 400 by default. To set their resolutions to 1024 * 768, modify the launch parameter
grub as follows:1. Run the following command to open the
grub file.vim /etc/default/grub
2. Press i to switch to the editing mode and add 
vga=792 to the end of the parameter value GRUB_CMDLINE_LINUX_DEFAULT, as shown below:
3. Click Esc and enter :wq to save and close the file.
4. Run the following command to update the
grub.cfg file.grub-mkconfig -o /boot/grub/grub.cfg
5. Run the following command to reboot the CVM.
reboot
Appendix
The VGA parameter values corresponding to different Linux instance resolutions are listed below:
Resolution | 640 * 480 | 800 * 600 | 1024 * 768 |
VGA | 786 | 789 | 792 |
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