Elastic Compute Service:Quickly create and use a cloud disk

Create a system disk

You can create a system disk when you create an ECS instance, but cannot separately create a system disk. The system disk is automatically initialized during ECS instance creation.

Create a data disk

You can create a data disk when you create an ECS instance or separately create a data disk.

In this example, a data disk is separately created, as shown in the following figure.

1. Create a data disk.

   Creation method	Operation
   Create an empty data disk	Create an empty data disk. Note The data disks that are created together with Windows ECS instances are automatically initialized upon creation. You can use the disks without additional operations.
   Use a snapshot to create a data disk that contains data	Create a data disk from a snapshot. A data disk created from a snapshot does not need to be initialized. You can use the data disk after you mount file systems on the disk.

2. Attach the data disk that you created to an ECS instance. For more information, see Attach a data disk.

   Note

   You do not need to perform this step if you created the cloud disk together with an ECS instance or if you selected the Attach to ECS Instance option during disk creation.

3. Perform subsequent operations based on whether the data disk you created contains data.

   Whether the data disk contains data	Subsequent operation
   Empty data disk	You must initialize the data disk to create partitions and mount file systems. For information about how to initialize a data disk, see Overview.
   Data disk created from a snapshot that contains data	The cloud disk already has partitions and file systems and does not need to be initialized. You need to only mount file systems on the disk. This way, the file systems can be recognized by the instance operating system and the cloud disk can be used for data storage. For more information, see the Only mount file systems section of the "Attach a data disk" topic.

Related operations

• When you use a disk, you can modify the disk attributes, change the disk category, encrypt the disk, or resize the disk based on your business requirements.

• If you no longer require a cloud disk, you can detach the disk from the associated instance and release the disk to reduce costs.

For more information, see Overview of Block Storage.