Overview

Image

An image is an ECS or BMS template that contains an OS or service data. It may also contain proprietary software and application software, such as database software. Images are classified into public, private, and shared images.

Image Management Service (IMS) allows you to easily create and manage images. You can create an ECS using a public image, private image, or shared image. You can also create a private image from an ECS or external image file.

What Are the Differences Between Backup, Snapshot, and Image?

You can use the cloud server backup function to create ECSs and the cloud disk backup function to create EVS disks.

An image can be a system disk image, data disk image, or full-ECS image.

Backup Type	Backup Object	Application Scenario	Differences and Advantages	Backup Method	Restoration Method
Cloud server backup	All disks (system and data disks) on an ECS	Hacker attacks and viruses You can use cloud server backup to restore data to the latest backup point at which the ECS has not been affected by hacker attacks and viruses. Accidental data deletion You can use cloud server backup to restore data to the backup point prior to the accidental deletion. Application update errors You can use cloud server backup to restore data to the backup point prior to the application update. System breakdown You can use cloud server backup to restore an ECS to the backup point in time prior to system breakdown.	All disks on an ECS are backed up at the same time, ensuring data consistency. In addition, you can configure backup policies for automatic backup.	Creating a Cloud Server Backup	Restoring Data Using a Cloud Server Backup How Do I Restore Data on the Original Server to a New Server?
Cloud disk backup	One or more specified disks (system or data disks)	Only data disks need to be backed up, because the system disk does not contain users' application data. You can use cloud disk backup to back up and restore data if an EVS disk is faulty or encounters a logical error, for example, accidental deletion, hacker attacks, and virus infection. Use backups as baseline data. After a backup policy has been set, the EVS disk data can be automatically backed up based on the policy. You can use the backups created on a timely basis as the baseline data to create new EVS disks or to restore the backup data to EVS disks.	Backup data is stored in OBS, instead of disks. This ensures data restoration upon disk data loss or corruption. Backup cost is reduced without compromising data security.	Creating a Disk Backup	Restoring from a Cloud Disk Backup Creating a Disk from a Cloud Disk Backup
Snapshot	One or more specified disks (system or data disks)	Routine data backup You can create snapshots for disks on a timely basis and use snapshots to recover your data in case that data is lost or inconsistent due to unintended actions, viruses, or attacks. Rapid data restoration You can create a snapshot or multiple snapshots before an application software upgrade or a service data migration. If an exception occurs during the upgrade or migration, service data can be rapidly restored to the time point when the snapshot was created. For example, if ECS A cannot be started due to a fault occurred in system disk A, you can create disk B using an existing snapshot of system disk A and attach disk B to a properly running ECS, for example ECS B. In this case, ECS B can read the data of system disk A from the disk B. Rapid deployment of multiple services You can use a snapshot to create multiple EVS disks containing the same initial data, and these disks can be used as data resources for various services, for example data mining, report query, and development and testing. This method protects the initial data and creates disks rapidly, meeting the diversified service data requirements. NOTE: A snapshot can only be rolled back to its source disk. Rolling back to another disk is not supported. If you have reinstalled or changed the ECS OS, snapshots of the system disk are automatically deleted. Snapshots of the data disks can be used as usual.	The snapshot data is stored with the disk data to facilitate rapid data back up and restoration. You can create snapshots to rapidly save disk data as it was at specified points in time. You can also use snapshots to create new disks so that the created disks will contain the snapshot data in the beginning.	Creating a Snapshot	Rolling Back Data from a Snapshot
System disk image	System disk	Rapid system recovery You can create a system disk image for the system disk of an ECS before OS change, application software upgrade, or service data migration. If an exception occurs during the migration, you can use the system disk image to change ECS OS or create a new ECS. Rapid deployment of multiple services You can use a system disk image to quickly create multiple ECSs with the same OS, thereby quickly deploying services these ECSs.	A system disk image can help an ECS with OS damaged to quickly change its OS.	Creating a System Disk Image	Changing the OS of a Faulty ECS Using a System Disk Image Creating an ECS from a System Disk Image'
Data disk image	Specific data disk	Rapid data replication You can use a data disk image to create multiple EVS disks containing the same initial data, and then attach these disks to ECSs to provide data resources for multiple services.	A data disk image can replicate all data on a disk and create new EVS disks. The EVS disks can be attached to other ECSs for data replication and sharing.	Creating a Data Disk Image	Purchasing an EVS Disk
Full-ECS image	All disks (system and data disks) on an ECS	Rapid system recovery You can create a full-ECS image for the system disk and data disks of an ECS before OS change, application software upgrade, or service data migration. If an exception occurs during the migration, you can use the full-ECS image to change ECS OS or create a new ECS. Rapid deployment of multiple services You can use a full-ECS image to quickly create multiple ECSs with the same OS and data, thereby quickly deploying services these ECSs.	A full-ECS image facilitates service migration.	Creating a Full-ECS Image	Creating an ECS from a Full-ECS Image

Public Image

A public image is a standard, widely used image that contains a common OS, such as Ubuntu, CentOS, or Debian, and preinstalled public applications. This image is available to all users. Select your desired public image. Alternatively, create a private image based on a public image to copy an existing ECS or rapidly create ECSs in a batch. You can customize a public image by configuring the application environment or software.

For more information about public images, see Overview.

Private Image

A private image contains an OS or service data, preinstalled public applications, and private applications. It is available only to the user who created it.

**Table 1** Private image types
Image Type	Description
System disk image	Contains an OS and application software for running services. You can use a system disk image to create ECSs and migrate your services to the cloud.
Data disk image	Contains only service data. You can use a data disk image to create EVS disks and migrate your service data to the cloud.
Full-ECS image	Contains an OS, application software, and data for running services. A full-ECS image contains the system disk and all data disks attached to it.
ISO image	Created from an external ISO image file. It is a special image that can only be used to create temporary ECSs.

If the image of a specified ECS is required, make sure that a private image has been created using this ECS.
If a local image file is required, make sure that the image file has been imported to the cloud platform and registered as a private image.
If a private image from another region is required, make sure that the image has been copied.
If a private image from another user account is required, make sure that the image has been shared with you.
A heterogeneous ECS with GPUs, NPUs, or encoding cards do not support private images in UEFI boot mode.

If you use a private image to create an ECS or change the OS, prepare this private image as instructed in Creating an Image. For more operations, see Managing Private Images.

An ECS can be booted in BIOS or UEFI mode. For details, see OSs Supporting UEFI Boot Mode.

A heterogeneous ECS with GPUs, NPUs, or encoding cards do not support private images in UEFI boot mode.

Shared Image

A shared image is a private image another user shared with you. For details, see Sharing Images.

Images can only be shared within a region.
Only the private images that have not been published in KooGallery can be shared.
A full-ECS image is shareable only when it is created from a CBR backup or from an ECS that has never had a CSBS backup. Full-ECS images created using other methods cannot be shared.
You can stop sharing an image anytime. For more information, see Stopping Sharing Images.
You can delete the images you have shared anytime. For details about the constraints and impacts, see Image Deletion FAQ.

KooGallery Image

A KooGallery image is a third-party image that has an OS, application environment, and software preinstalled. You can use such an image for website setup, application development, and visualized management with just a few clicks. No additional configurations are required.

A KooGallery image can be free or paid, based on the image service providers. When you use a paid image to create an ECS, you need to pay for the KooGallery image and ECS.

How Do I Select an Image?

You must select an image when creating an ECS. The following table lists the factors you need to consider when selecting an image.

**Table 2** Factors for image selection
Factor	Description
Region and AZ	An image is a regional resource. You cannot use an image to create an ECS in a different region. For example, when creating an ECS in region A, you can only select an image that is already in region A. For more information, see Region and AZ. If you want to use an image to create an ECS in a different region, replicate the image to that region first. For details, see Replicating Images Across Regions.
Image type	You can select an image as follows: If you only need an OS, select a public image. If you want to clone an existing ECS, select a private image. If you want to use an image shared by others, select a shared image. If you need a complete software environment, such as a Magento e-commerce system, select a KooGallery image.
OS	For details, see OSs Supported by Different Types of ECSs.
Billing	You may be billed for using an image. For details, see IMS Billing.
Pre-installed software	KooGallery images are preinstalled with an instance running environment or software. You can select an image with a desired environment or software to create an ECS. For more information, see KooGallery Images.

How to Use an Image

**Table 3** Common operations on private images
Operation	Description	Reference
Creating an image	If cloud servers identical to an ECS is required for service deployment, you can use that ECS to create a private image and then use the image to create those cloud servers quickly.	Creating an Image
Importing an image	If a local image file is required, make sure that the image file has been imported to the cloud platform and registered as a private image.	Creating a Private Image from an Image File External Image File Formats and Supported OSs
Replicating an image	You can replicate an image from one region to another. You can convert encrypted and unencrypted images into each other through in-region image replication. If you replicate an image shared with you, that image will become your private image.	Replicating Images Across Regions Replicating Images Within a Region Replicating a Shared Image
Exporting an image	After creating a private image, you can export it to a standard OBS bucket and then download it to your local PC.	Exporting an Image
Modifying an image	You can modify the name, description, memory, and boot mode of a private image as needed.	Modifying an Image
Deleting an image	You can delete a private image that is no longer needed.	Deleting Images

Public images are provided by the Huawei Cloud system and are visible to all users. They are adaptable to ECS and BMS, compatible with most mainstream OSs, and are preinstalled with necessary plug-ins. For details, see Managing Public Images.

You can export an image list as a CSV file to your local PC. Then, you can view image details in the list. For details, see Exporting an Image List.

**Table 4** Using an Image
Operation	Description	Reference
Creating an ECS	You can use a private image to quickly create ECSs with the same OS, applications, and user data, without having to configure these ECSs repeatedly.	Purchasing an ECS Using a Private Image
Changing the OS	If you have selected the wrong image or your service requirements have changed, you can change the image of your ECS.	Changing the OS
Sharing an image	You can share your private images with other users. After accepting a shared image, they can use this image to create the same ECSs.	Sharing Images