Problem description
After you expand a disk in the Elastic Computing Service (ECS) console, the Disk Management tool in your Windows server still shows the original disk capacity. The operating system has not recognized the new, larger size.
Causes
Instance not restarted after offline expansion: If you perform an offline expansion on a system or data disk in the ECS console but do not restart the instance, the operating system continues to use the old, cached disk information. The instance must be restarted for the operating system to detect the new disk capacity during boot.
Abnormal expansion detection: The operating system may fail to automatically detect the new disk size. This can be caused by an interruption in the update process or by driver issues.
Solutions
Use case 1: Restart the instance and check the disk capacity
Restart the instance.
Go to the ECS console - Instances. In the upper-left corner of the page, select the resource group and region of the target instance.
Click the target instance ID to go to the instance details page. In the upper-right corner of the page, click Restart, and then click Confirm.
Log on to the Windows instance again. Confirm that the disk capacity is updated to the post-expansion size.
The added space appears as unallocated.
Use case 2: Resolve abnormal expansion detection issues
Solution 1: Manually scan disks online
If you cannot restart the instance immediately because it would interrupt your services, you can manually trigger a rescan of disk devices to detect the new capacity.
Log on to the ECS instance and open Command Prompt as an administrator.
Execute the
diskpartcommand to start the disk partition management tool.Execute the
rescancommand. This instructs the operating system to rescan all storage buses for new or changed hardware.Wait for the scan to complete. Then, execute the
exitcommand to exit the DiskPart tool.Check if the disk capacity is now displayed correctly.
The added space appears as unallocated.
Solution 2: Check storage drivers
Right-click the Start menu and select Device Manager.
Expand the Storage Controllers and Disk Drives categories.
Check for any abnormal devices marked with a yellow exclamation point icon.
If an abnormal device exists, right-click the device and select Properties. On the General tab, view the error code in the Device Status box.
Based on the specific error code, find the corresponding solution in the Microsoft official documentation: Error codes in Device Manager in Windows.
For error code 19 (incomplete or corrupted registry information), see How do I check for residual disk driver entries in the registry of a Windows ECS instance?