Help Center/ Elastic Volume Service/ User Guide (Paris Region)/ Getting Started/ Create an EVS Disk
Updated on 2024-03-26 GMT+08:00
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Create an EVS Disk

Scenarios

EVS disks can be used as system disks or data disks for servers. You can create data disks on the EVS console, or create them together with system disks on the ECS console.

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

Constraints

Table 1 Constraints on creating disks

Created On

Description

The EVS console
  • Disks created on the EVS console are data disks. You need to manually attach them to servers.
  • Disks can only be attached to servers in the same region and AZ. Once created, the region and AZ cannot be changed.
  • There are quantity and capacity quotas on EVS disks, so properly plan the number of disks and total disk capacity your workloads require. For details, see Managing Quotas.

The ECS console
  • System disks can only be created together with servers and are automatically attached.
  • Data disks created together with servers or added after the server creation are automatically attached.
  • Disks will have the same billing mode as their server if the disks are created together with the server.
  • By default, disks created with ECSs are VBD disks, and those created with BMSs are SCSI disks.

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Capacities of multiple disks cannot be combined, and the capacity of a single disk cannot be split.

Procedure

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

    The disk list page is displayed.

  3. Click Create Disk.
  4. Configure basic disk information according to Table 2.

    Table 2 Disk parameters

    Parameter

    Description

    Example Value

    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.

    -

    Disk Specifications

    Mandatory

    • Common I/O
    • Ultra-high I/O
    • General Purpose SSD
    • Extreme SSD

    Common I/O

    Disk Size (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 the 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.

    20 GiB

    Create from backup

    Optional

    Specifies to create the disk from a backup.

    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.

    autobackup-001

    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 backup is not required. If you need backup protection after a disk has been created, log in to the CBR console, locate the desired vault, and associate the disk with the vault.
    • Use existing:
      1. Vault: Select an existing vault from the drop-down list.
      2. Backup Policy: Select a backup policy from the drop-down list, or go to the CBR console and configure a desired one.
    • Buy new:
      1. Vault Name: Enter a vault name, which can contain a maximum of 64 characters, including letters, digits, periods (.), underscores (_), and hyphens (-), for example, vault-f61e. The default naming rule is vault_xxxx.
      2. Vault Capacity: 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.
      3. Backup Policy: Select a backup policy from the drop-down list, or go to the CBR console and configure a desired one.

    Do not use

    Share

    Optional

    • If Share is not selected, a common disk is created.
    • If Share is selected, a shared disk is created, and the shared disk can be attached to multiple servers.

    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.

    For details about shared EVS disks, see Managing Shared EVS Disks.

    -

    SCSI

    Optional

    • If you do not select SCSI, a VBD disk is created. VBD is the default device type of EVS disks.
    • 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.
    NOTE:

    The device type of a disk cannot be changed after the disk has been created.

    For details about the ECS types, OSs, and ECS software supported by SCSI EVS disks, see Device Types and Usage Instructions.

    -

    Encryption

    Optional

    Disk encryption is used for data disk encryption only. System disk encryption relies on the image. 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
      NOTE:

      KMS Key Name is displayed only after the KMS access rights have been granted. For details, see "Create Agency" above.

      KMS 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. 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 evs/default.
      • CMKs: Existing or newly created CMKs. For details, see Management > Creating a CMK in the Key Management Service User Guide.
    NOTE:
    • Before you use the 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.

    For details, see EVS Encryption.

    -

    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 can contain a maximum of 36 characters, including letters, digits, and underscores (_).

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

      A tag value can contain a maximum of 43 characters, including letters, digits, underscores (_), periods (.), and hyphens (-).

    NOTE:
    • A maximum of 10 tags can be added for an EVS disk.
    • Tag keys of the same EVS disk must be unique.
    • Except for tagging the disk during disk creation, you can also add, modify, or delete tags for existing disks. For details, see Managing a Tag.

    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

    Optional

    The number of disks to be created. The default value is set to 1, which means only one disk is 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.

    1

  5. Click Create Now.
  6. On the Details page, check the disk details.

    • If you do not need to modify the specifications, click Submit.
    • If you need to modify the specifications, click Previous.

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

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

Parent topic: Getting Started