This topic describes what is disk resizing, the procedure on how to resize a disk, disk capacity limits, and charges for disk resizing. Both system disks and data disks can be resized.
Disk resizing
When the capacity of a disk does not meet your storage requirements, you can resize the disk by extending its capacity.
Procedure

- Resize a disk that is attached to an Elastic Compute Service (ECS) instance in the ECS console.
For more information, see Resize disks online for Linux and Windows instances.
- Connect to the ECS instance and extend the partitions and file systems of the disk in the operating system. Before you extend the partitions and file systems, you must decide on what extending operations to perform based on the following factors: whether the disk is partitioned, the partition format, and the new disk size.
Operation References Unpartitioned disk (raw disk): Directly extend the file systems. Extend the partitions and file systems of disks on a Linux instance Partitioned disk If the disk is resized to up to 2 TiB, directly extend the partitions and file systems. If the disk is GPT-formatted and is resized to more than 2 TiB, directly extend the partitions and file systems. If the disk is MBR-formatted and is resized to more than 2 TiB, you must convert the disk into a GPT disk and then extend its partitions and file systems.
- Method 1: Create a disk, attach the disk to the ECS instance as a data disk, and then manually initialize the disk. For more information, see Create a disk.
- Method 2: Replace the system disk with a large disk. For more information, see Replace the operating system of an instance.
Capacity limits
- System disk: 500 GiB
- Data disk: 32,768 GiBNote An ESSD AutoPL disk, enhanced SSD (ESSD), standard SSD, or ultra disk can be up to 32,768 GiB in size. A basic disk (retired previous-generation disk) can be up to 2,000 GiB in size.
For example, assume that an instance has a 40 GiB system disk. When you resize this system disk, the specified new capacity must be greater than 40 GiB but cannot exceed 500 GiB.
Charges
- For a subscription disk, you must pay the price difference between the new capacity and the original capacity based on the remaining subscription duration.
- For a pay-as-you-go disk, the new capacity takes effect immediately after the disk is resized, and the disk is billed on a pay-as-you-go basis for the new capacity.
If you have purchased Storage capacity units, they are automatically applied to offset the bills of pay-as-you-go disks. For more information, see EBS devices.