Creating a Full-ECS Image from an ECS

Scenarios

You can create an image of an entire ECS, including not just the OS, but also the software and all the service data. You can then use this image to migrate data by quickly provisioning exact clones of the original ECS.

This section does not apply to a BMS.

Background

The following figure shows the process of creating an image from an entire ECS, with both the system and data disks included.

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 quality, and the number of concurrent tasks.
• The 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.
• If an ECS is in Stopped state, do not start it when you are using it to create a full-ECS image.
• When a full-ECS image is being created from an ECS, do not perform any operations on the ECS, or the image creation may fail.
• In Figure 1, if there are snapshots of the system disk and data disks but the ECS backup creation is not complete, the full-ECS image you create will only be available in the AZ where the source ECS is and can only be used to provision ECSs in this AZ. You cannot provision ECSs in other AZs in the region until the original ECS is fully backed up and the full-ECS image is in the Normal state.
• If you use a full-ECS image to change an ECS OS, only the system disk data can be written into the ECS. Therefore, if you want to restore or migrate the data disk data of an ECS by using a full-ECS image, you can only use the image to create a new ECS rather than use it to change the ECS OS.

Constraints

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

  For details, see How Do I Configure an ECS, BMS, or Image File Before I Use It to Create an Image?

• A Windows ECS used to create a full-ECS image cannot have a spanned volume, or data may be lost when ECSs are created from that image.
• A Linux ECS used to create a full-ECS image cannot have a physical disk group or a logical disk that contains multiple physical disks, or data may be lost when ECSs are created from that image.
• An ECS used to create a full-ECS image cannot contain a Dedicated Distributed Storage Service (DSS) disk.
• A full-ECS image cannot be published in KooGallery.
• A full-ECS image cannot be exported.
• A full-ECS image cannot be replicated within a region.
• Cross-region replication of full-ECS images is only available for certain regions.

  If a full-ECS image cannot be replicated to a different region, you can use it to create an ECS, use the ECS to create a system disk image and a data disk image, and replicate the images to the destination region.

  A full-ECS image created using an ECS backup can be replicated from the region where they reside to another region, but the replicated full-ECS image cannot be replicated across regions again.

• 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. For details, see Setting the ECS SAN Policy to OnlineAll.

Procedure

1. Log in to the IMS console.
2. Create a full-ECS image.
   1. Click Create Image in the upper right corner.
   2. Set image parameters.
      You need to 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.	Create 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.	Full-ECS image
      Source	A source is the original data required for creating a private image. Select a source based on your requirements. Generally, a data source can be a cloud server, a CSBS backup, or a CBR backup. NOTE: The new full-ECS image and its backup generated during image creation need to be stored in a 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 and vaults, see What Is CBR?	ECS

      Figure 3 Image information
      

      Table 2 Parameters for configuring image information

      Parameter	Description	Example Value
      Name	Set a name for the image.	-
      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.	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 check the new full-ECS image status.
   • When the image status changes to Normal, the image creation is complete.
   • If Available in AZX is displayed under Normal in the Status column for a full-ECS image, the backup for the source ECS has not been created and only a disk snapshot is created. (AZX indicates the AZ where the source ECS of the image resides.)

     In this case, the full-ECS image can only be used to provision ECSs in this AZ. If you want to use this image to provision ECSs in other AZs of the region, you need to wait until Available in AZX disappears from under Normal, which indicates that the ECS backup has been successfully created. This process takes about 10 minutes, depending on the data volume of the source ECS.

     Figure 4 Full-ECS image status
     
     

     When you use an ECS to create a full-ECS image, the ECS will be locked and protected, and some operations on the ECS will be disabled. For details, see the information displayed on the console. If the full-ECS image creation time exceeds your expected maintenance window, you can unlock the ECS by deleting the full-ECS image that is being created. Ensure that you retain the cloud backups associated with the full-ECS image during deletion.

Follow-up Procedure

• 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.
  

  When you use a full-ECS image to create an ECS:

  • The system and data disk information defaulted by the image will be automatically displayed.
  • If the full-ECS image contains multiple data disks, it takes some time to load and display the disk information.
• If you use a full-ECS image to change an ECS OS, only the system disk data can be written into the ECS. Therefore, if you want to restore or migrate the data disk data of an ECS by using a full-ECS image, you can only use the image to create a new ECS rather than use it to change the ECS OS.
• If you want to share the full-ECS image with other tenants, you can use either of the following methods:
  • If the ECS from which the full-ECS image was created has a CSBS backup, you must first migrate the backup to CBR before you share the image because CSBS is being deprecated. For details, see Resource Migration from CSBS/VBS.
  • If the ECS has no such a backup, you can share the full-ECS image directly.

Setting the ECS SAN Policy to OnlineAll