Scenarios

You can use an ECS with data disks to create a full-ECS image, which contains an OS, application software, your service data and can be used to quickly provision identical ECSs for data migration.

Background

The following figure shows the process of creating a full-ECS image from an ECS.

Figure 1 Creating a full-ECS image from an ECS

• The time required for creating a full-ECS image depends on the disk size, network status, and number of concurrent tasks.
• An ECS used to create a full-ECS image must be in Running or Stopped state. To create a full-ECS image containing a database, use a stopped ECS.
• When a full-ECS image is being created, do not detach the system disk from the ECS or stop, start, or restart the ECS. Otherwise, the image creation will fail.
• In Figure 1, when the snapshots of the system disk and data disks are created but the ECS backup creation has not been complete, the full-ECS image is available only in the AZ where the source ECS is located. That is, the full-ECS image can be used to provision ECSs only in this AZ. You can provision ECSs in the region only after the ECS backup is created successfully and the full-ECS image status changes to Normal.
• To restore or migrate data disk data by using a full-ECS image, create a new ECS to do it instead of changing the OS of an existing ECS.

Constraints

• When creating a full-ECS image from an ECS, ensure that the ECS has been properly configured. Otherwise, creating ECSs using the full-ECS image may fail.

  For details, see What Initial Configuration Needs to Be Performed on the ECS, BMS, or Image File Before It Is Used to Create an Image?

• A Windows ECS used to create a full-ECS image cannot have a spanned volume. Otherwise, data may be lost when the full-ECS image is used to create ECSs.
• A Linux ECS used to create a full-ECS image cannot have a disk group or logical disk that contains multiple physical disks. Otherwise, data may be lost when the full-ECS image is used to create ECSs.
• An ECS used to create a full-ECS image cannot contain a Dedicated Distributed Storage Service (DSS) disk.
• A full-ECS image cannot be exported, published in Marketplace, or replicated within a region.
• When creating a full-ECS image from a Windows ECS, you need to change the SAN policy of the ECS to OnlineAll. Otherwise, EVS disks attached to the ECSs created from the image may be offline.

  Windows has three types of SAN policies: OnlineAll, OfflineShared, and OfflineInternal.

  Table 1 SAN policies in Windows

  Type	Description
  OnlineAll	All newly detected disks are automatically brought online.
  OfflineShared	All disks on sharable buses, such as iSCSI and FC, are left offline by default, while disks on non-sharable buses are kept online.
  OfflineInternal	All newly detected disks are left offline.

  1. Execute cmd.exe and run the following command to query the current SAN policy of the ECS:

     diskpart

  2. Run the following command to view the SAN policy of the ECS:
     san

     • If the SAN policy is OnlineAll, run the exit command to exit DiskPart.
     • If the SAN policy is not OnlineAll, go to 3.
  3. Run the following command to change the SAN policy of the ECS to OnlineAll:

     san policy=onlineall

Procedure

1. Log in to the management console.
2. Under Computing, click Image Management Service.

   The IMS console is displayed.

3. Click Create Image in the upper right corner.
4. In the Image Type and Source area, select Full-ECS image for Type.
5. Select ECS for Source and then select an ECS from the list.
   Figure 2 Creating a full-ECS image using an ECS
   
6. Specify Server Backup Vault to store backups.

   The created full-ECS image and backup are stored in the server backup vault.

   If no server backup vault is available, click Create Server Backup Vault to create one. Ensure that you select Backup for Protection Type. For more information about CBR backups and vaults, see What Is CBR?

7. In the Image Information area, configure basic image information, such as the image name and description.
8. Click Next.
9. Confirm the parameters. Read and select the agreement, and click Submit.
10. Switch back to the Image Management Service page to view the image status.

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

Follow-up Operations

• If you want to use the full-ECS image to create ECSs, click Apply for Server in the Operation column. On the displayed page, create ECSs by following the instructions in Elastic Cloud Server User Guide.
  

  If a full-ECS image contains one or more data disks, the system automatically configures data disk parameters when you use the image to create ECSs.

• If you want to share the full-ECS image with other tenants, you can use either of the following methods depending on the ECS status:
  • If a CSBS backup has been created for the ECS used to create the full-ECS image, you must migrate the CSBS backup to CBR before sharing the full-ECS image. For details, see How Do I Share a Full-ECS Image Created from a CSBS Backup with Other Tenants?
  • If no CSBS backup has been created for the ECS used to create the full-ECS image, you can share the full-ECS image directly.