Purchasing an EVS Disk

Scenarios

You can use EVS disks as system disks or data disks for servers. You can purchase data disks on the EVS console, or purchase them together with system disks on the cloud server console.

This section describes how to purchase data disks on the EVS console.

Notes and Constraints

Procedure

1. Log in to the management console.
2. Click in the upper left corner and choose Storage > Elastic Volume Service.

   The Elastic Volume Service page is displayed.

3. In the upper right corner, click Buy Disk.
4. Configure basic disk information according to Table 2.

   Table 2 Disk parameters

   Parameter	Sub-Parameter	Description	Example Value
   Billing Mode	-	Mandatory Pay-per-use	Pay-per-use
   Region	-	Mandatory Resources are region-specific and cannot be used across regions through internal network connections. For low network latency and quick resource access, select the nearest region.	-
   AZ	-	Mandatory The availability zone (AZ) where you want to create the disk. NOTE: Disks can only be attached to the servers in the same AZ. The AZ of a disk cannot be changed after the disk has been created.	AZ1
   Data Source (Optional)	Create from Backup Snapshot Image	Optional Create from Backup: The backup data is used to create the disk. Click Create from and choose Backup. On the displayed page, select the target backup and click OK. NOTE: One backup cannot be used for concurrent disk creation operations at the same time. For example, if you are creating disk A from a backup, this backup can be used to create another disk only after disk A has been created. If a disk is created from a backup of a system disk, the new disk can be used as a data disk only. Create from Snapshot: The snapshot data is used to create the disk. Click Create from and choose Snapshot. On the displayed page, select the target snapshot and click OK. NOTE: For details about how to create disks from snapshots, see Creating a Disk from a Snapshot. Create from Image: The image data is used to create the disk. Click Create from and choose Image. On the displayed page, select the target image and click OK. NOTE: The device type of the new disk is the same as that of the image's source disk. The encryption attribute of the new disk is the same as that of the image's source disk.	Create from Backup: autobackup-001
   Disk Specifications	Disk Type	Mandatory EVS disk types vary depending on regions. See the EVS types displayed on the console. To learn more about disk types, see Disk Types and Performance.	Ultra-high I/O
   	Capacity (GiB)	Mandatory The disk size. Only data disks can be created on the current page, and the disk size ranges from 10 GiB to 32,768 GiB. NOTE: When you use a backup to create a disk, the disk capacity must be greater than or equal to the backup size. In the condition that you do not specify a disk capacity, if the backup size is smaller than 10 GiB, the default capacity 10 GiB will be used as the disk capacity; if the backup size is greater than 10 GiB, the disk capacity will be consistent with the backup size. When you use a snapshot to create a disk, the disk capacity must be greater than or equal to the snapshot size. In the condition that you do not specify a disk capacity, if the snapshot size is smaller than 10 GiB, the default 10 GiB will be used as the disk capacity; if the snapshot size is greater than 10 GiB, the disk capacity will be consistent with the snapshot size. The system shows you the maximum number of disks as well as the maximum disk capacity allowed to purchase. To ensure effective resource usage, if the disk capacity you need exceeds the upper limit, click Increase Quota to obtain a higher quota. You can purchase the disk capacity you need after the request is approved.	100 GiB
   More	Advanced Settings Share SCSI Encryption	Optional Share If you select Share, a shared disk is created. A shared disk can be attached to up to 16 servers. If you do not select Share, a non-shared disk is created, and the disk can be attached to one a server only. If you select both SCSI and Share, a shared SCSI disk is created. NOTE: The sharing attribute of a disk cannot be changed after the disk has been created. SCSI If you select SCSI, a SCSI disk is created. Such disks allow the server OS to directly access the underlying storage media and send SCSI commands to the disks. If you do not select SCSI, a VBD disk is created. That said, the disk device type is VBD, the default device type. NOTE: The device type of a disk cannot be changed after the disk has been created. Encryption This option is only used to encrypt data disks, and you need to create an agency to grant KMS access rights to EVS. After the access rights are granted, configure the KMS key name on the Encryption Settings page displayed: A key name is the identifier of the key, and you can use KMS Key Name to specify a KMS key and use it for encryption. You can select one of the following keys: Default Key: After the KMS access rights have been granted to EVS, the system automatically creates a Default Key evs/default. An existing or new custom key. For details, see Creating a Key. NOTE: System disk encryption relies on the image. For details, see Creating Encrypted Images. Before using the encryption function, you need to create an agency to grant KMS access rights to EVS. If you have the right to grant the permission, grant the KMS access rights to EVS directly. After the KMS access rights have been granted, follow-up operations do not require the rights to be granted again. If you do not have this permission, contact a user with the security administrator permissions to grant KMS access rights to EVS, then repeat the preceding operations. The encryption attribute of a disk cannot be changed after the disk has been created.	-
   More	Tag	Optional You can add tags when creating disks. Tags can help you identify, classify, and search for your disks. For details about tag rules, see Adding a Tag. NOTE: Tag rules vary depending on regions. See the rules displayed on the console. Except for tagging the disk during disk creation, you can also add, modify, or delete tags for existing disks. For more information about tags, see Managing EVS Tags.	-
   Enterprise Project	-	Mandatory When creating EVS disks, you can add the disks to an existing enterprise project. An enterprise project facilitates project-level management and grouping of cloud resources and users. The default project is default.	default
   Disk Name	-	Mandatory If you create a single disk, the name you entered will be used as the disk name. The name can contain a maximum of 64 characters. If you create multiple disks in a batch, the name you entered will be used as the prefix of disk names. An actual disk name will be composed of the name you entered and a four-digit number. The name can contain a maximum of 59 characters.	For example, if you create two disks and set volume for Disk Name, the EVS disk names will be volume-0001 and volume-0002.
   Quantity	-	(Optional) The preset disk quantity is 1, which means only one disk is created. You can create a maximum of 100 disks at a time. NOTE: If the disk is created from a backup, batch creation is not possible, and this parameter must be set to 1. If the disk is created from a snapshot, batch creation is not possible, and this parameter must be set to 1. The system shows you the maximum number of disks as well as the maximum disk capacity allowed to purchase. To ensure effective resource usage, if the number of disks you need exceeds the upper limit, click Increase Quota to obtain a higher quota. You can purchase the disks you need after the request is approved.	1

5. Click Next.
   1. On the Details page, check the disk information again.
   2. Confirm the information and click Submit. The system displays a message indicating request submitted successfully.
   3. Click Back to Disk List to return to the Elastic Volume Service page.

6. In the disk list, view the disk status.

   When the disk status changes to Available, the disk is successfully created.