You can resize disks to meet increasing storage requirements as your business and application data grow. This topic describes the maximum sizes to which disks can be resized and how to resize disks in different scenarios.

Scenarios

You can use the following methods to increase the storage capacity of an instance:

  • Resize an existing disk. You must resize the existing partitions of the disk or create new partitions on the disk.
    The following table describes the two methods for resizing an existing disk.
    Method Limit References
    Resize a disk online The instance to which the disk is attached must be in the Running (Running) state. For more information about limits, see the topics in the References column.

    After you resize the disk, the new size automatically takes effect without the need to restart the instance.

    Resize a disk offline The instance to which the disk is attached must be in the Running (Running) or Stopped (Stopped) state. For more information about limits, see the topics in the References column.

    After you resize the disk, you must restart the instance by using the Elastic Compute Service (ECS) console or by calling the RebootInstance operation for the new size to take effect.

  • Create a disk, attach the disk to an ECS instance, and then partition and format the disk.
  • Replace the system disk of an instance and specify a greater size for the new system disk. For more information, see Replace the system disk (public images).

Size ranges of resized system disks

The new size of a resized system disk must be greater than the original size but less than or equal to 500 GiB. The following table describes the size ranges of resized system disks that correspond to different images used by instances.

Image Size range of a resized system disk (GiB)
CoreOS and FreeBSD [Max{30, Original size of the system disk}, 500]
Other Linux distributions [Max{20, Original size of the system disk}, 500]
Windows Server [Max{40, Original size of the system disk}, 500]

For example, the system disk on a CentOS instance is 35 GiB in size. When you resize this system disk, the specified new size must be greater than 35 GiB but less than or equal to 500 GiB.

Maximum sizes of resized data disks

The new size of a resized data disk must be greater than the original size. The following table describes the maximum sizes of resized data disks of different categories.

Disk category Maximum size of a resized data disk (GiB)
Enhanced SSD (ESSD), standard SSD, or ultra disk 32,768
Basic disk 2,000

Billing method

For information about the billing methods of resized disks, see Elastic Block Storage devices.