Purchasing an EVS Disk

Scenarios

If the storage space on your servers is insufficient, you can buy EVS disks to add more storage space. This section describes how to buy new EVS disks.

Constraints

Billing

• EVS disks are billed based on the disk type, capacity, and usage duration. For details, see Billing for EVS Disks.
• If you create disks together with the servers, the disks will have the same billing mode as their servers.
• Separately purchased yearly/monthly disks that attached to a cloud server later cannot be renewed or unsubscribed from together with the server. Such disks may expire earlier than the server, and if this happens, service may be interrupted.
• If KMS encryption is used, what you use beyond the free quota given by KMS will be billed. For details, see DEW Billing.

Video Tutorial

Buying Disks On the EVS Console

1. Sign in to the EVS console.
2. Click in the upper left corner and select a region.
3. In the upper right corner, click Buy Disk.
4. Configure disk parameters according to Table 3.

   Table 3 Parameter description

   Parameter	Example Value	Description
   Region	-	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	AZ1	The availability zone (AZ) where you want to create the disk.
   Attach to Server	Now	Optional Now: If you select this option, you need to select a server to attach the disk. The billing mode of the disk will be the same as the selected server. Later: When no server is available, you can select this option to create the disk first and attach the disk after the purchase. NOTE: This parameter is available only in some regions. Whether it is displayed depends on the region where you use EVS.
   Billing Mode	Pay-per-use	You can pay for EVS disks in two ways: Yearly/Monthly Pay-per-use NOTICE: Selecting Now for Attach to Server: If you select a yearly/monthly server, only yearly/monthly billing is available for the disk. If you want to buy a pay-per-use disk for the yearly/monthly server, select Later for Attach to Server, buy a pay-per-use disk, and attach it to the yearly/monthly server after the purchase. If you select a pay-per-use server, only pay-per-use billing is available for the disk. If you want to buy a yearly/monthly disk for the pay-per-use server, select Later for Attach to Server, buy a yearly/monthly disk, and attach it to the pay-per-use server after the purchase. Selecting Later for Attach to Server: If you buy a yearly/monthly disk and attach it after the purchase, the disk cannot be renewed or unsubscribed from together with its server and may have an expiration time different from the server.
   Data Source (Optional) Create from backup Create from snapshot Create from image	Create from backup: autobackup-001	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. 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.
   Disk Specifications > Disk Type	Ultra-high I/O	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. NOTE: General Purpose SSD V2 disks allow you to specify the disk IOPS and throughput. You can change the disk type after a disk is created. For details, see Changing the EVS Disk Type (OBT).
   Disk Specifications > Capacity (GiB)	100 GiB	The disk capacity. You can only create data disks on the current page. The disk capacity ranges from 10 GiB to 32,768 GiB. NOTE: The system shows you the remaining disk space you can purchase. 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.
   More > Advanced Settings Share SCSI Encryption	-	Optional Share If you select Share, a shared disk will be created. A shared disk can be attached to up to 16 servers. If you do not select Share, a non-shared disk will be created, and the disk can be attached to one server only. If you select both Share and SCSI, a shared SCSI disk will be created. NOTE: For details about shared EVS disks, see Managing Shared EVS Disks. SCSI If you select SCSI, a SCSI disk will be 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 will be created. That said, the disk device type is VBD, the default device type. NOTE: To learn more about the ECS types and OSs supported by SCSI disks and the requirements on the ECS software, see Device Types. Encryption This option is only used to encrypt data disks, and you need to create an agency to grant KMS access permissions to EVS. After the access permissions are granted, configure the following parameters on the Encryption Setting page displayed: Select an existing key If you select Select an existing key, select a key from the drop-down list. You can select one of the following keys: Default keys: After KMS access permissions are granted to EVS, the system automatically creates a default key and names it evs/default. Custom keys: You can choose an existing key or create a new one. For details about how to create a key, see Creating a Custom Key. Enter a key ID If you select Enter a key ID, enter an ID of a key shared with you by another account. Ensure that the shared key is in the same region where you want to create the disk. For details, see Creating a Grant for a Custom Key. Keys can only be shared with accounts, not users. NOTE: System disk encryption depends on images. For details, see Encrypting Images. Before using encryption, you need to create an agency to grant KMS access permissions to EVS. If you have the right to grant the permission, grant KMS access permissions to EVS directly. After KMS access permissions are granted, follow-up operations do not require the permissions to be granted again. If you do not have this permission, contact a user with the security administrator permissions to grant KMS access permissions to EVS, then repeat the preceding operations.
   Disk Name	Assume that you create two disks and enter volume for Disk Name, the EVS disk names will be volume-0001 and volume-0002.	Mandatory If you create a single disk, the name you entered will be used as the disk name. The value 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. Each disk name will be composed of the name you entered and a four-digit number. The value can contain a maximum of 59 characters.
   Automatic Backup	-	CBR lets you back up EVS disks and ECSs and use the backups to restore data. After you configure automatic backup, the system will associate the EVS disk with the backup vault and apply the selected policy to the vault to periodically back up the disk. Do not use: Skip this configuration. If you need backup protection after a disk has been purchased, go to the CBR console, locate the desired vault, and associate the disk with the vault. Use existing: Vault: Select an existing vault from the drop-down list. Backup Policy: Select a backup policy from the drop-down list, or go to the CBR console and configure a desired one. Buy new: Enter a vault name, which can contain a maximum of 64 characters, including letters, digits, underscores (_), and hyphens (-), for example, vault-f61e. The default naming rule is vault_xxxx. Enter a vault capacity for storing disk backups. The vault capacity cannot be less than the size of the disk to be backed up. The value ranges from the disk size to 10,485,760 in the unit of GiB. Select a backup policy from the drop-down list, or go to the CBR console and configure a desired one.
   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	default	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.
   Quantity	Usage Duration: 1 year Quantity: 1	Usage Duration: This parameter is mandatory if you select Yearly/Monthly for Billing Mode. You can choose from 1 month to 3 years. Quantity: This parameter is optional. The preset disk quantity is 1, which means one disk will be created. You can create a maximum of 100 disks at a time. NOTE: The system shows you the remaining number of disks you can purchase. 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.

5. Click Next.
   • If you select Yearly/Monthly for Billing Mode:
     1. Check the disk details on the confirmation page.
     2. Confirm the information and click Submit.
     3. On the Pay page, select a desired payment method and confirm the payment. The system displays a message indicating payment processed successfully.
     4. Click Back to Elastic Volume Service to return to the Elastic Volume Service page.
   • If you select Pay-per-use for Billing Mode:
     1. Check the disk details on the confirmation page.
     2. Confirm the information and click Submit. The system displays a message indicating request submitted successfully.
     3. Click Go 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.

7. Perform follow-up operations. After new disks are purchased, attach and initialize them based on different scenarios.

   Scenario	Follow-up Operations
   Choosing to attach the disk to an ECS when purchasing the disk	Initialize the data disk. To initialize disks in Linux, see Initializing a Linux Data Disk (Less Than or Equal to 2 TiB) and Initializing a Linux Data Disk (Greater Than 2 TiB). To initialize disks in Windows, see Initializing a Windows Data Disk.
   Choosing not to attach the disk to any server when purchasing the disk	Attach and initialize the data disk. Step 1: Attach the disk. For details, see Attaching an EVS Disk. Step 2: Initialize the data disk. To initialize disks in Linux, see Initializing a Linux Data Disk (Less Than or Equal to 2 TiB) and Initializing a Linux Data Disk (Greater Than 2 TiB). To initialize disks in Windows, see Initializing a Windows Data Disk.

Related Links

• To store data on EVS disks, upload files to ECSs by referring to How Do I Upload Files to My ECS?
• You can also create EVS disks through API calls. For details, see Creating EVS Disks.
• To create EVS disks from snapshots, see Creating a Disk from a Snapshot.