Overview

You can use Huawei Cloud EulerOS in the following ways:

Selecting HCE OS as the public image when creating an ECS
Changing an OS to HCE OS
If the ECS OS needs to be changed but the other ECS details (NICs, disks, and VPNs) need to be kept the same, as long as the software is loosely coupled to the OS, you can change the OS to HCE OS with only a few additional changes needed.
Migrating an OS to HCE OS
If you want to change an ECS OS but retain other ECS details (NICs, disks, and VPNs) and the OS component parameter settings, you can migrate the OS to HCE OS.

The OS can be migrated only to Huawei Cloud EulerOS 2.0 Standard Edition or Huawei Cloud EulerOS 1.1 CentOS-compatible Edition.

**Table 1** Differences between OS change and OS migration
Item	OS Change	OS Migration
Data backup	Data in all partitions of the system disk will be lost, so back up the system disk data before you change the OS. The data in data disks remains unchanged.	System disk data is not lost, but you are still advised to back up the system disk data, in case there are any system software exceptions. The data in data disks remains unchanged.
Custom settings	After the OS is changed, custom settings such as DNS and hostname will be reset and need to be reconfigured.	After the OS is changed, custom settings such as DNS and hostname do not need to be reconfigured.