Creating a Data Disk Image from an External Image File

Scenarios

A data disk image contains only service data. You can create a data disk image using a local image file or an external image file (image file on another cloud platform). Then, you can use the data disk image to create EVS disks and migrate your service data to the cloud.

Process

The following figure shows the process of creating a data disk image from an external image file.

Figure 1 Creating a data disk image from an external image file

1. Prepare an external image file. The file must be in VHD, VMDK, QCOW2, RAW, VHDX, QCOW, VDI, QED, ZVHD, or ZVHD2 format. If you want to use an image file in other formats, convert the file into any of the listed formats before importing it to the cloud platform.

   For details about image file format conversion, see Converting the Image Format Using qemu-img or Converting the Image Format Using qemu-img-hw.

2. Upload the external image file to a Standard OBS bucket. For details, see Upload an Image File.
3. Create a data disk image. For details, see Procedure.
4. Use the data disk image to create data disks. For details, see Follow-up Procedure.

Procedure

1. Log in to the IMS console.
2. Create a data disk image.
   1. Click Create Image in the upper right corner.
   2. Set image parameters as required.

      Set parameters in two areas: Image Type and Source and Image Information. For details about the parameters, see Table 1 and Table 2.

      Figure 2 Image type and source
      

      Table 1 Parameters for configuring the image type and source

      Parameter	Description	Example Value
      Region	Resources in different regions cannot communicate with each other over an intranet. For low latency and fast access, select a region close to where your services will be provided.	-
      Type	Private images can be created or imported.	Import Image
      Image Type	A private image contains an OS or service data, preinstalled public applications, and a user's personal applications. Private images are only available to the users who created them. A private image can be a system disk image, data disk image, ISO image, or full-ECS image. A system disk image contains an OS and preinstalled software for various services. You can use a system disk image to create ECSs and migrate your services to the cloud. A data disk image contains only service data. You can use a data disk image to create EVS disks and use them to migrate your service data to the cloud. An ISO image is created from an external ISO image file. It is a special image that is not available on the ECS console. It can only be used to provision temporary cloud servers. A full-ECS image contains an OS, preinstalled software, and service data. A full-ECS image is created using differential backups and the creation takes less time than creating a system or data disk image that has the same disk capacity.	Data disk image
      Select Image File	Select the bucket storing the image file from the bucket list and then select the image file. NOTE: The image file format must be VHD, ZVHD, VMDK, QCOW2, RAW, ZVHD2, VHDX, QCOW, VDI, or QED. For details about common image formats, see Common Image Formats. Only image files that have been uploaded to a Standard OBS bucket are available for use. The size of each image file must be less than 128 GiB, except for ZVHD2 and RAW image files. The image file must have been configured with necessary settings. For details, see How Do I Configure an ECS, a BMS, or an Image File Before I Use It to Create an Image? The format and size of the new image may be different from the source image file. Fast Create can be used to quickly create an image. However, the image file must be converted to the RAW or ZVHD2 format and must be optimized. For details, see Overview.	-
      Fast Create	This parameter is available only when you select a ZVHD2 or RAW image file. This function enables fast image creation and supports import of large files (maximum: 1 TB) as long as the files to be uploaded are converted to ZVHD2 or RAW format and optimized. If you have already prepared an image file that meets the requirements, select Enable Fast Create and select the confirmation checkbox in the Image File Preparation row. NOTE: To learn how to convert image file formats and generate bitmap files, see Fast Import of an Image File.	-

      Figure 3 Image information
      

      Table 2 Parameters for configuring image information

      Parameter	Description	Example Value
      Auto sign	If you select this option, the system will sign the image for high data reliability. Key Name: Select a key from the drop-down list. The key is used to sign the image. If there is no key available, log in to the DEW console and create a key. Key ID: After you select a key, its ID will be automatically displayed. NOTE: A signed image cannot be shared with other users. Check on the console to see if Auto sign is available.	-
      OS	This parameter must be specified, which can be Windows or Linux.	-
      Data Disk	The size of the data disk. The value range is from 40 GiB to 2,048 GiB, and must be no less than the size of the data disk in the image file.	-
      Name	Set an image name that is easy to identify.	-
      Encryption	This parameter is optional. If you want to encrypt the image, select KMS encryption and select the key to be used from the key list. After you select KMS encryption, the system will create a default key ims/default. You can also select a key from the key list. For details about how to encrypt an image, see Introduction.	-
      Enterprise Project	This parameter is for enterprise users. To use this function, contact customer service to enable it. An enterprise project groups cloud resources, so you can manage resources and users by project. The default project is default. Select an enterprise project from the drop-down list. For more information, see Accessing the Enterprise Center.	default
      Tag	This parameter is optional. Set tag keys and values for the image to make identification and management easier. You are advised to create predefined tags in TMS. For details, see Creating Predefined Tags. NOTE: If your organization has configured tag policies for images, you need to add tags to your images based on the policies. Otherwise, tags may fail to be added. For details about image tag format, see Image Tag Format.	-
      Description	This parameter is optional. Enter a description for the image.	-
      Agreement	Read and agree to the Image Disclaimer	-

   3. Click Next. Confirm the settings and click Submit.

3. Go back to the private image list and view the new data disk image.

   When the image status changes to Normal, the image creation is complete.

Follow-up Procedure

If you want to use the created data disk image to create an EVS disk and attach it to an ECS, you can perform either of the following operations:

• Locate the row that contains the created data disk image and click Create Data Disk to create one or multiple data disks. Then attach the data disks to an ECS.
• On the page for creating ECSs, click Create Disk from Data Disk Image and select the data disk image.
  

  In this way, a data disk image can be used to create a data disk for an ECS only once. For example, a data disk created from the data disk image data_disk_image has been added to the ECS. No other data disk created from this image can be added to the ECS.

  Figure 4 Adding data disks