How Do I Select an Image?

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

Region and AZ

An image is a regional resource. You cannot use an image to create an instance in a different region. For example, when creating an instance in region A, you can only select an image that is already in region A. For more regions, see Region and AZ.

Image Type

Images are classified into public images, private images, and shared images. A private image can be a system disk image, data disk image, or full-ECS image. For details, see What Is Image Management Service?

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

    Windows

    • Programs developed for Windows (for example, .NET).

    • Databases such as SQL Server. (You need to install the database.)

    The system disk must be at least 40 GB, and there must be at least 1 GB of memory.

    Linux

    • High-performance server applications (for example, Web) and working with 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.