Making snapshot is an important method for data sharing and migration. Cloud disks created using a snapshot own all data in the snapshot. You can use a snapshot to create a cloud disk whose capacity is greater than or equal to that of the snapshot.
When you use a snapshot to create a data disk of the same size as the snapshot, the new data disk doesn't need to be initialized. You can directly attach it, right-click
> Disk Management, and set it to Online to bring it online in the CVM instance, after which it can be normally read and written.
When you use a snapshot to create a data disk whose capacity is greater than that of the snapshot, the system only expand the storage block and does not extend the file system or convert the partition format. After you mount the new data disk, it can only use the file system and data of the source snapshot and cannot use the new disk space. You need to manually extend the file system and convert the partition format.
For example, if you want to a 3 TB data disk by using a data disk snapshot that uses the MBR partition format and has a capacity of 1 TB, you need to format the data disk in GPT partition style because the maximum disk space supported in MBR partition style is 2 TB. Note that this operation will delete original data.
This document describes how to use a snapshot to create a cloud disk on the Snapshot List page. When creating a cloud disk, you can configure the Snapshots parameter to specify a snapshot for creating the cloud disk.
Directions
Creating a cloud disk with a snapshot in the console
2. On the row of the target snapshot, select More > Create Cloud Disk.
3. In the Purchase Data Disk pop-up window, configure the following parameters:
Parameter
Configuration
AZ
Required.
The availability zone where the created cloud disk resides. It cannot be modified after the cloud disk is created.
Cloud Disk Type
Required.
For more information on cloud disk types, see Cloud Disk Types.
Capacity
Required.
For more information on the cloud disk capacity and specifications, see Performance metrics. When you create a cloud disk with a snapshot, the disk capacity cannot be smaller than that of the snapshot. If you don't specify the capacity of the cloud disk, the capacity is equal to that of the snapshot by default.
Snapshots
Optional. To use a snapshot to create a cloud disk, select Create a Cloud Disk with a Snapshot and select the required snapshot.
The disk capacity is the same as that of the snapshot by default. You can adjust the capacity to be greater than that of the snapshot.
The disk type is the same as that of the snapshot by default. You can change the cloud disk type.
Disk Name
Optional.
A maximum of 20 characters are supported. It must start with a letter and can be a combination of letters, digits, and special symbols (`.`, `_`, `:`, and `-`). This parameter can be modified after the cloud disk is created.
If you create only one cloud disk, the disk name is the name of the cloud disk you create.
If you create multiple cloud disks at one time, the disk name entered will be used as he prefix of the final disk name, in the format of disk name_number, for example, "disk name_0" to "disk name_49".
Projects
Required.
When creating a cloud disk, you can configure the project to which the cloud disk belongs. The default value is Default Project.
Label
Optional.
When creating a cloud disk, you can bind a tag to it. A tag is used for identification, helping you categorize and search cloud resources. For more information on tags, see Tag.
Billing mode
Required.
The cloud disk supports the following billing modes:
Monthly subscription. If this mode is selected, you must set the Purchase Period.
Pay-as-you-go.
Scheduled Snapshot
Optional.
When creating a cloud disk, you can select Scheduled Snapshot to create snapshots for the cloud disk periodically based on the created scheduled snapshot policy. For more information, see Scheduled Snapshot.
Quantity
Optional.
The default value is 1, meaning only one cloud disk is created. Currently, up to 50 cloud disks can be created at a time.
Validity Period
If the Billing mode is Monthly Subscription, this parameter is required. Value range: One month to five years.
If the Billing Mode is Pay-as-you-go, this parameter is not involved.
Automatic Renewal
If the Billing Mode is Monthly Subscription, this parameter is optional. If you select Auto-renewal, auto-renewal will be performed on the device monthly upon expiration if your account has a sufficient balance.
If the Billing Mode is Pay-as-you-go, this parameter is not involved.
4. Click OK.
If the Billing Mode is Pay-as-you-go, the creation is completed.
If the Billing Mode is Monthly Subscription, the Information Verification page will be popped up.
4.1.1 After you confirm the specifications, select whether to use a voucher as needed and click Submit Order.
4.1.2 Complete the payment.
5. You can view the cloud disk you created in the Cloud Disk List. The new elastic cloud disk is in the To be attached status. To attach it to a CVM instance in the same AZ, see Attaching Cloud Disks.
Using an API to create a cloud disk from snapshot
You can use the CreateDisks API to create a cloud disk. For more information, see CreateDisks.
