Help Center/ Elastic Volume Service/ Best Practices/ Repartitioning a Windows System Disk Through Volume Shrink
Updated on 2025-08-04 GMT+08:00
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Repartitioning a Windows System Disk Through Volume Shrink

If you need a new partition but have no more disks available, you can shrink from the end of an existing volume to free up unallocated space and then use the space to create a new volume.

  • You can shrink a raw partition or a partition that uses NTFS.
  • Shrinking a volume that contains data (such as database files) may damage the data.
  • When you shrink a volume, the system automatically moves files to other locations on the disk to free up space. There is no need to reformat the disk to shrink the partition.

Prerequisites

You are advised to back up data before shrinking volumes to prevent any data loss caused by misoperations.

Procedure

The following operations are based on Windows Server 2019.

  1. Remotely log in to the ECS.

    For how to log in to an ECS, see Logging In to an ECS.

  2. On the Windows Server desktop, right-click and choose Disk Management from the shortcut menu.
  3. In the Disk Management window, choose Action > Rescan Disks to view disk information.

    Figure 1 Rescan Disks

  4. Right-click the target volume (volume C in this example) and choose Shrink Volume... from the shortcut menu.

    Figure 2 Shrink Volume

  5. On the displayed Shrink C: page, enter the amount of space to shrink and click Shrink.

    • Enter the amount of space to shrink in MB indicates the size of the unallocated space after the shrink. Its default value is the same as the value of Size of available shrink space in MB. Change it as required.
    • Total size after shrink in MB indicates the remaining size of the volume (volume C in this example) after the shrink.

    After the shrink is complete, unallocated space is displayed to the right of volume C.

  6. Right-click the unallocated space and choose New Simple Volume... from the shortcut menu.

    Figure 3 New Simple Volume

  7. Click Next as prompted and retain the default settings until the formatting is complete.

    You can now see new volume D.

    Figure 4 New Volume