You can resize both system disks and data disks as described in this topic. The size of the disks is expected to increase as your business and application data grows.

What is offline resizing?

In the offline mode, you can see that cloud disks are extended only after you restart instances by using the console or API (RebootInstance). Instances can be in the running (Running) or stopped (Stopped) state.


System limits
  • For more information about thresholds of extended system disks and data disks, see Overview.
  • When you resize cloud disks, only storage capacity is extended, but not file systems. You can allocate your own storage space after resizing. For more information, see Next operations.
What is not supported
  • You cannot resize a cloud disk for which a snapshot is being created.
  • After you click Renew for Configuration Downgrade for a subscription instance, you cannot resize subscription cloud disks of the instance during the remaining period of the current billing cycle.
  • You cannot resize system disks of Windows Server 2003 instances.
  • If a data disk adopts the MBR partition format, you cannot resize the data disk to more than 2 TiB. If you want to resize a data disk to 2 TiB while the MBR partition format is used, we recommend that you create and attach another data disk. Format a GPT partition and copy the data in the MBR partition to the GPT partition.
What is supported
  • You can resize cloud disks which are in the in use (In Use) state. This occurs when instances to which the disks are attached are in the running (Running) or stopped (Stopped) state.
  • You can resize basic disks, ultra disks, standard SSD, and enhanced SSDs (ESSDs).
  • For Windows instances, you can only resize the NTFS file system.


Create a snapshot for data backup, to prevent data loss caused by any errors.


Perform the following steps to resize a cloud disk in the ECS console:

  1. Locate the cloud disk to be extended. Choose More > Resize Disk in the Actions column.
  2. Set the extended capacity, which must be greater than the current capacity.
  3. Confirm the fee, read ECS Service Terms and Product Terms of Service, and then click Confirm to Resize.
  4. Complete the payment.
  5. Restart the instance for the changes to take effect.
    Note You can see that cloud disks are extended only after you restart instances by using the console or API (RebootInstance). It does not work if you perform the restart operation in the instance operating system.

Related API: You can also call ResizeDisk to perform the resize operation.

Next operations

The following table lists the available operations after you resize a cloud disk. However, this depends on whether the cloud disk is attached and partitioned.

Disk status A disk that is not attached or partitioned A disk that is attached but not partitioned A disk that is attached and partitioned

If a data disk is in the available (Available) state, the extended capacity takes effect after you complete the payment. Then you can perform the following steps:

  1. Log on to the console or use the API (AttachDisk) to attach a cloud disk.
  2. Resize or format a partition:
You can perform the following steps:
  1. Resize or format a partition:
  2. Resize a file system:

Resize a partition and file system: