Help Center > > Getting Started> Step 2: Purchase an EVS Disk

Step 2: Purchase an EVS Disk

Updated at:Jan 08, 2021 GMT+08:00

Scenarios

EVS disks can be used system disks or data disks of servers.

  • When a server is created, the system disk is automatically purchased and attached. You do not need to purchase the system disk separately. The maximum capacity of a system disk is 1024 GB.
  • Data disks can be purchased during or after the server purchase. If you purchase data disks during the server purchase, the system will automatically attach the data disks to the server. If you purchase data disks after the server creation, you need to manually attach the purchased data disks to the server. The maximum capacity of a data disk is 32768 GB.
  • The billing mode of the disk purchased with the server is the same as that of the server.
  • A yearly/monthly disk purchased with a yearly/monthly server cannot be attached to other servers.

This topic describes how to separately purchase disks on the EVS console.

Procedure

  1. Log in to the management console.
  2. Under Storage, click Elastic Volume Service.

    The disk list page is displayed.

  3. Click Buy Disk.
  4. Configure basic disk information according to Table 1.

    Table 1 Parameter description

    Parameter

    Sub-Parameter

    Description

    Example Value

    Billing Mode

    -

    Mandatory

    You can pay for EVS disks in two ways:

    • Yearly/Monthly
    • Pay-per-use

    Yearly/Monthly

    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

    Specifies 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

    Disk Specifications

    Disk Type

    Mandatory

    The disk type cannot be changed after the purchase is complete.

    The available disk types are as follows:

    • Common I/O (previous generation product)
    • High I/O
    • General Purpose SSD
    • Ultra-high I/O
    NOTE:

    When a disk is created from a snapshot, the disk type of the newly created disk will be consistent with that of the snapshot's source disk.

    Ultra-high I/O

    Capacity (GB)

    Mandatory

    Specifies the disk size. Only data disks can be created on the current page, and the disk capacity ranges from 10 GB to 32768 GB.

    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 the disk capacity, if the backup size is smaller than 10 GB, the default capacity 10 GB will be used as the disk capacity; if the backup size is greater than 10 GB, 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 the disk capacity, if the snapshot size is smaller than 10 GB, the default capacity 10 GB will be used as the disk capacity; if the snapshot size is greater than 10 GB, 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 GB

    Select Data Source
    • Create from backup
    • Create from snapshot
    • Create from image
    Optional
    • If you choose Create from backup, the backup data is used to create the disk.

      Click Select Data Source and choose Create from 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.
    • If you choose Create from snapshot, the snapshot data is used to create the disk.

      Click Select Data Source and choose Create from snapshot. On the displayed page, select the target snapshot and click OK.

      NOTE:
      • The disk type of the new disk is the same as that of the snapshot's source disk.
      • The device type of the new disk is the same as that of the snapshot's source disk.
      • The encryption attribute of the new disk is the same as that of the snapshot's source disk.
    • If you choose Create from image, the image data is used to create the disk.

      Click Select Data Source and choose Create from 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.
      • If a disk is created from an image, the encryption attribute of the disk will be the same as that of the image's source disk.
    • Create from backup: autobackup-001
    • Create from snapshot: snapshot-001

    Cloud Backup and Recovery

    -

    Cloud Backup and Recovery (CBR) lets you back up EVS disks and ECSs and use the backups for restoration. After you set Cloud Backup and Recovery, the system binds the EVS disk to the cloud backup vault and associates the disk with the selected backup policy to periodically back up the disk.
    • Do not use: Skip this configuration if CBR is not required. If you still need to set backup protection after a disk is successfully purchased, log in to the CBR console, locate the target vault, and bind the disk to the vault.
    • Use existing
      1. Select an existing cloud backup vault from the drop-down list.
      2. Select a backup policy from the drop-down list, or log in to the CBR console and configure a desired one.
    • Buy now:
      1. Set the name of the cloud backup vault, which is a character string consisting of 1 to 64 characters, including letters, digits, underscores (_), and hyphens (-), for example, vault-f61e. The default naming rule is vault_xxxx.
      2. Enter the vault capacity, which is required for backing up the disk. 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 GB.
      3. Select a backup policy from the drop-down list, or log in to the CBR console and configure a desired one.

    -

    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.

      When 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

      The encryption function on this console is used for data disk encryption only. System disk encryption depends on images. For details, see the Image Management Service User Guide.

      To use the disk encryption function, select Encryption. The displayed dialog box contains the following parameters:
      • Create Agency

        An agency is a trust relationship between two tenants or services. A tenant can create an agency to grant resource access rights to another tenant or service. If the KMS access rights are not granted to EVS, the Create Agency dialog box will be displayed. Otherwise, it will not be displayed.

        Click Yes to grant the KMS access rights to EVS. After the rights have been granted, EVS can obtain KMS keys to encrypt or decrypt EVS disks.

        After the KMS access rights have been granted, follow-up operations do not require the rights to be granted again.

      • KMS Key Name

        KMS Key Name is displayed only after the KMS access rights have been granted.

        KMS Key Name is the identifier of the key, and you can use KMS Key Name to specify the KMS key that is to be used for encryption. One of the following keys can be used:

        Default Master Key: After the KMS access rights have been granted to EVS, the system automatically creates a Default Master Key and names it evs/default.

        CMKs: Existing or newly created CMKs. For details, see Key Management Service > Creating a CMK in the Data Encryption Workshop User Guide.

      NOTE:
      • Before you use the EVS disk encryption function, KMS access rights need to be granted to EVS. If you have the right to grant the permission, grant the KMS access rights to EVS directly. If you do not have this permission, contact a user with the security administrator rights 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.

    -

    Tag

    Optional

    During the EVS disk creation, you can tag the EVS resources. Tags identify cloud resources for purposes of easy categorization and quick search.

    A tag is composed of a key-value pair.
    • Key: Mandatory if the disk is going to be tagged

      A tag key is a string of no more than 36 characters. It consists of letters, digits, underscores (_), hyphens (-), and Unicode characters (\u4E00-\u9FFF).

    • Value: Optional if the disk is going to be tagged

      A tag value is a string of no more than 43 characters. It consists of letters, digits, underscores (_), periods (.), hyphens (-), and Unicode characters (\u4E00-\u9FFF).

    NOTE:
    • A maximum of 10 tags can be added for an EVS disk.
    • Tag keys of the same EVS disk must be unique.

    For details about tags, see the Tag Management Service User Guide.

    -

    Disk Name

    -

    Mandatory

    • If you create disks individually, this parameter value is used as the actual disk name.

      The name can contain a maximum of 64 characters.

    • If you create disks in a batch, this parameter value is used as the prefix of disk names, and one disk name will be composed of this parameter value 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

    -

    • Usage duration: This parameter is mandatory if you select Yearly/Monthly for Billing Mode.

      You can choose 1 month to 3 years for the usage duration.

    • Disk quantity: This parameter is optional.

      The default value is set to 1, which means one disk will be created. Currently, you can create up to 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.

    Disk validity period: 1 year

    Disk quantity: 1

  5. Click Next.

    • If you select Yearly/Monthly for Billing Mode,
      1. Check the disk details on the Confirm 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 Confirm page.
      2. Confirm the information and click Submit. The system displays a message indicating task submitted successfully.
      3. Click Back to Disk List to return to the Elastic Volume Service page.

  6. Click Back to Disk List.
  7. Go back to the disk list page and view the disk status.

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

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