Use a snapshot to create a disk for data replication-Elastic Compute Service(ECS)-阿里云帮助中心

The new disk is an exact copy of the source data disk when the snapshot was created. This lets you replicate cloud disk data within the same zone or across zones for tasks like cloning environments or creating backups. This topic describes how to create a data disk from a snapshot.

Prerequisites

You have created a snapshot of the cloud disk and have its snapshot ID. For more information, see Create a snapshot for a disk.
If you plan to attach the cloud disk to an ECS instance during creation, you need the ID of the target ECS instance.

Limitations

You cannot create data disks from snapshots of local disks or elastic temporary disks because snapshots are not supported for these disk types.
You cannot format multiple block storage devices to combine them into a single volume. We recommend that you plan the number and capacity of your block storage devices in advance.
A cloud disk created from a system disk snapshot can be used only as a data disk. If you want to use a snapshot to restore data to the original system disk, see Roll back a cloud disk by using a snapshot.

Procedure

Note

You can create a cloud disk from a snapshot from several entry points: the cloud disk purchase page (in the Cloud Disk section, select Create from Snapshot), the instance purchase page (in the Data Disk section, select Create from Snapshot), or the Snapshots page. This topic uses the Snapshots page as an example.

Go to ECS console - Snapshots.
In the upper-left corner of the page, select a region and resource group.
Find the snapshot you want to use to create a cloud disk. In the Operation column, choose > Create Disk.

On the cloud disk purchase page, configure the following parameters.

Parameter	Description
Attach	Specifies whether to attach the new cloud disk to an instance immediately after creation. Not Attach: Creates a cloud disk without attaching it to an ECS instance. If you select this option, you can create only pay-as-you-go cloud disks. A cloud disk must be in the same zone as the instance it will be attached to, except for Regional ESSDs. Therefore, select the Region and Zone carefully. Attach to ECS Instance: Creates a cloud disk and attaches it to a specified ECS instance in the same zone. This zone restriction does not apply to Regional ESSDs, as they can be attached to any supported instance within their region. For more information, see Limitations. If you select this option, you must select the destination region and ECS instance.
Billing Method	Specifies the billing method for the cloud disk. Pay-as-you-go: You can attach a pay-as-you-go cloud disk to either a subscription or a pay-as-you-go ECS instance. Subscription: You must attach a subscription cloud disk to a subscription ECS instance.
Dedicated Block Storage Clusters	Specifies whether to add the disk to a Dedicated Block Storage Cluster by selecting Enable Dedicated Block Storage Cluster. Cloud disks in a Dedicated Block Storage Cluster use physically isolated resources for your exclusive use. For more information, see Dedicated Block Storage Cluster.
Cloud Disk	The snapshot information is automatically populated. Select the category and capacity for the new cloud disk. The capacity of the new cloud disk must be greater than or equal to the capacity of the snapshot's source disk. Important If you set a capacity for the new cloud disk that is larger than the capacity of the source disk, you must extend the partition and file system on the new disk to use the additional space. If the source disk is smaller than 2,048 GiB but you want the new disk to be larger than 2,048 GiB, first verify that the source disk uses the GUID Partition Table (GPT) partition format. You can check this by running the `fdisk -lu` command and checking if the `Disk label type` is `gpt`. If not, set the new capacity to less than 2,048 GiB to avoid the risk of data loss during partitioning. For more information, see Initialize a data disk for a Linux instance. Performance: This parameter is available only for ESSDs. You can select a performance level based on the ESSD capacity. Different performance levels provide different I/O performance. For more information, see ESSDs. Multi-attach: This feature, available for ESSDs, allows a single disk to be attached to multiple instances in the same zone. For more information, see Enable the multi-attach feature. Encrypt: When enabled, this feature automatically encrypts data on the cloud disk. For more information, see Encrypted disks. Provisioned Performance Fee and Enable Burst: For an ESSD AutoPL disk, you can configure its provisioned IOPS and burst IOPS. For more information, see ESSD AutoPL disks. Release Settings: When you select Attach to ECS Instance and the billing method for the cloud disk is Pay-as-you-go, you can configure whether the cloud disk and automatic snapshots are released with the instance.

Confirm the configuration and cost, and complete the purchase.

After the disk is created, return to the Cloud Disks page to view the new disk. The disk is not yet ready to use on an ECS instance.

Next steps:

Important

A cloud disk created from a snapshot already contains partitions and a file system, so it does not need to be initialized. You only need to attach it to an ECS instance and mount its file system. The operating system can then recognize and use the disk.

Scenario	Next steps
You selected Attach to ECS Instance when creating the cloud disk.	Perform a `mount` operation or bring the disk online. Linux instance Connect to the ECS instance to which the disk is attached and run the following command to `mount` the partition: `sudo mount <partition_name> <mount_point>` `<partition_name>`: Run the `sudo fdisk -lu` command to obtain the partition name. Example: `/dev/vdc`. `<mount_point>`: This can be an existing directory, or you can create one by running a command such as `sudo mkdir -p <new_directory>`. Example: `sudo mkdir -p /data`. Example `mount` command: `sudo mount /dev/vdc /data` Add the new partition information to the `/etc/fstab` file to automatically mount the partition at startup. For more information, see Initialize a data disk for a Linux instance. Windows instance Connect to the ECS instance. Click the Start icon and select Disk Management. Find the target disk, right-click a blank area of the disk, and select Online. (Conditionally required) If you attach the new disk to the same Linux ECS instance as the source disk, their UUIDs will conflict. You must then change the UUID of the new disk. For more information, see Modify the UUID of a cloud disk. (Conditionally required) If the new disk's capacity is larger than the source disk's, you must extend the partition and file system to use the additional space. For Linux instances, see Extend a partition and a file system of a Linux instance. For Windows instances, see Extend a partition and a file system of a Windows instance. (Optional) Configure the disk partition to automatically mount at startup. For more information, see Initialize a data disk for a Linux instance.
You selected Not Attach when creating the cloud disk.	You must attach the cloud disk to an ECS instance and mount its file system. For more information, see Attach a data disk.