What Is an Image?

An image is a template of the BMS running environment. It contains an OS and runtime environment, and some pre-installed applications. An image file is equivalent to a copy file that contains all data in the system disk.

Image Types

Images can be classified into public images, private images, and shared images.

**Table 1** Image types
Image Type	Description
Public image	A public image is provided by the cloud platform and is available to all users. It contains an OS and preinstalled public applications.
Private image	A private image is created by a user and is available only to the user who created it. It contains an OS, pre-installed public applications, and the user's private applications. Using a private image to create BMSs frees you from repeatedly configuring BMSs.
Shared image	A shared image is a private image other users share with you.

Public Images

Public images are provided by the system. These images are available to all users, compatible with BMSs and most mainstream OSs, and are pre-installed with necessary plug-ins. Public images available to you vary depending on the BMS flavor you selected. For details, see OSs Supported by Different Types of BMSs.

Characteristics

OS types: Linux and Windows OSs that are updated and maintained periodically

Pre-installed software: plug-ins that BMS storage, networks, and basic functions depend on

These plug-ins are necessary for BMSs to run properly. Do not delete or modify any of them. Otherwise, basic BMS functions will be affected.

**Table 2** Pre-installed software
Software	Description
Cloud-Init	Cloud-Init is an open-source cloud initialization program, which initializes specific configurations, such as the host name, key, and user data, of a newly created BMS.
bms-network-config	This plug-in is used to automatically configure BMS networks during BMS provisioning and restore the BMS network when the network is interrupted due to faults.
SDI iNIC frontend driver plug-in	This plug-in is installed in the image so that EVS disks can be attached to BMSs. In this way, BMSs can be booted from EVS disks, facilitating quick BMS provisioning.

Compatibility: compatible with server hardware
Security: highly stable and licensed
Restrictions: no restrictions on usage

Private Images

A private image contains an OS, preinstalled public applications, and a user's private applications. You can use a private image to create BMSs without having to repeatedly configure them.

Characteristics

Compatibility: Private images can be used to deploy servers that are of the same model as the source BMS and may fail to deploy servers of other models.
Functions: You can create and delete private images, as well as create BMSs and reinstall the BMS OS using private images.
Restrictions: You can create a maximum of 50 private images.

Shared Images

A shared image is a private image other users share with you.

Application Scenarios