Help Center/ Image Management Service/ FAQs/ Image Consulting/ How Do I Select an Image?
Updated on 2025-09-23 GMT+08:00
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How Do I Select an Image?

When creating an ECS or a BMS, you can select an image based on the following factors:

Image Type

Images are classified into public, private, and shared images.

Table 1 Image types

Image Type

Description

Availability/Security

Billing

Public

A public image is a standard, widely used image. It contains an OS and preinstalled public applications and is available to all users. Public images are very stable and their OS and any included software have been officially authorized for use.

High

Free

Private

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.

Medium
  • System disk image, ISO image, or data disk image: free

    OBS buckets are used in the background for free image storage.

  • Full-ECS image: charged for the storage on CSBS or CBR

    If the image is created from a CSBS or CBR backup, you will be billed for the space used to store the CSBS or CBR backup.

Shared

A shared image is a private image another user has shared with you.

Low
  • If it is a system or data disk image, the OBS storage is free.
  • If it is a full-ECS image, you will be billed for the space used to store the CBR backup.
    NOTE:

    Full-ECS images created from a CBR backup can be shared but those created from a CSBS backup cannot.

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.

Image Fee

You may be billed for using an image. For details, see What Are the Billing Standards for IMS?

OS

When selecting an OS, consider the following factors:

  • Architecture types

    System Architecture

    Applicable Memory

    Constraints

    32-bit

    Smaller than 4 GB
    • If the instance memory is greater than 4 GB, a 32-bit OS cannot be used.
    • A 32-bit OS only allows addressing within a 4 GB memory range. An OS with more than 4 GB memory cannot be accessed.

    64-bit

    4 GB or larger

    If your application requires more than 4 GB of memory or the memory may need to be expanded to more than 4 GB, use a 64-bit OS.
  • OS types

    OS Type

    Applicable Scenario

    Constraints

    Linux
    • High-performance server applications (for example, Web) and common programming languages such as PHP and Python
    • Databases such as MySQL. (You need to install the database.)

    The system disk must be at least 40 GB, and there must be at least 512 MB of memory.
Parent topic: Image Consulting