<p>Re-installing operating system is a risky operation. Back up data before re-installation. This article describes how to re-install system.</p> <p><strong>Prerequisites</strong></p> <p>1．&nbsp; If an ECS instance is created with a private image, make sure the original image still exists.</p> <p>2．&nbsp; The ECS instance status is <strong>stopped</strong>. An instance in the status of <strong>running</strong> or <strong>being restarted</strong> cannot re-install system.</p> <p>3．&nbsp; Back up your personal data before re-installing system to avoid data loss.</p> <p>4．&nbsp; An instance bound to EIP cannot re-install system. Release the bound EIP.</p> <p>5．&nbsp; An instance with two network cards cannot re-install system. Delete Network Card 1 before re-installation.</p> <p><strong>Usage Guidelines</strong></p> <p>1．&nbsp; System re-installation requires to stop the instance and will interrupt your business. We recommend that you do not restart system in peak time of your business.</p> <p>2．&nbsp; System re-installation can switch operating system type. After it is completed, the original system disk will return to its primary status and data will completely loss. We recommend that you back up data before re-installation.</p> <p>3．&nbsp; After the re-installation is completed, IP address and MAC address of the instance will not be changed. System disk ID will be updated and original system disk is released, namely allocating another system disk for your instance. If you have set automatic snapshot policy for the old system disk, and automatic snapshots are set to be released with the disk, the snapshot policy is not applicable to the new system disk. Automatic snapshots of the old one will be automatically deleted. Snapshots created on the basis of old system disk cannot be used to roll back the new system disk.</p> <p>4．&nbsp; Re-installation cross operating systems will reset the instance name but host name remains. File system format of data disk may not be recognized, so uninstall data disk before re-installation.&nbsp;</p> <p>5．&nbsp; System re-installation requires to reset login password. If associated keys are used for login, they will be automatically canceled after re-installation and need to be manually bound before using them for login.</p> <p><strong>Procedures</strong></p> <p>1．Log in to the <a href="#https://yun.pingan.com/console/ecs/overview" target="_blank">ECS Console</a>.</p> <p>2．In the left navigation pane, click <strong>Instance</strong> to enter the <strong>Instance Management</strong> page.</p> <p>3．Select the target region. In the operation column of the target instance, click <strong>More &gt; Operations Management &gt; System Reinstallation</strong>.</p> <p>4．On the <strong>System Reinstallation</strong> page that opens, enter relevant information.</p> <p>5．Read the instructions in the prompt box, and confirm name of the instance to be re-installed and current image. Select disable root or administrator account, enter password, and click <strong>Confirm</strong>.</p> <p><strong>Note:</strong></p> <p>You can check off <strong>Disable root/administrator account</strong> when re-installing system in Ping An Cloud. If you select to disable the account, you need to enter the custom account name and password. After system re-installation is completed, root/administrator account will be disabled. You can use the custom account and password to log in to instances after re-installation.</p> <p>6．In the dialog box of <strong>Verification Code</strong> that opens, enter the verification code.</p> <p>7．Click <strong>OK</strong>.</p> <p><strong>Note:</strong></p> <ul> <li>&nbsp;Back up your system disk data before system re-installation.</li> <li>&nbsp;System re-installation only supports login with a custom password.</li> <li>System re-installation takes about three to five minutes. Be patient.</li> </ul> <p><strong>Result</strong></p> <p>The instance status turns into <strong>Pending</strong> and will be <strong>Running</strong> after completion.</p> <p><strong>Subsequent Procedures</strong></p> <p><strong>1.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </strong><strong>Set automatic snapshot policy for new system disk</strong></p> <p>If automatic snapshot policy is set for the original system disk, it will invalidate after system re-installation is completed. You need to reset and bind snapshot policy. For more information, see set snapshot policy.&nbsp;</p> <p><strong>2.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </strong><strong>Re-mount Data Disk</strong></p> <p>If the original instances are mounted to data disks and uninstall data disk before system re-installation, instances need to be re-mounted to data disks after starting new system. You need to perform mount operation again and write /etc/fstab file in Linux system. For more information, see mount data disk.</p>