Batch Changing OSs of FlexusL Instances

Scenarios

Huawei Cloud Operations Center (COC) allows you to change the OSs of multiple FlexusL instances in batches on the COC console.

Notes

• An OS change does not make any changes to server specifications.
• After the OS is changed, the server IP address remains unchanged.
• Data in all partitions (including the system partition) of the system disk will be cleared, so you are advised to back up the system disk data prior to an OS change.
• An OS change does not affect data in data disks.
• After the OS is changed, the original OS is not retained.
• After you change the OS, you need to deploy services in the new OS.
• After the OS is changed, the server automatically starts.
• Do not reset the password of, restart, or stop the FlexusL instance immediately after the OS is changed. Wait for several minutes until the system successfully injects the password, or the login will fail.

Constraints

• FlexusL fixed packages do not support batch OS changes. However, you can change the OS of an individual FlexusL fixed package.

• Application images have the minimum CPU and memory specification requirements. If the specification of a FlexusL instance is low, you cannot change its OS using an application image that requires higher specifications. For example, you cannot change the OS of a FlexusL instance with 2 vCPUs and 4 GiB memory using the GitLab application image that needs to use at least 2 vCPUs and 8 GiB memory. To do so, upgrade the FlexusL instance by performing Modifying the Specifications of a FlexusL Instance first and try again.
• After the OS is changed, the login password is cleared. You need to reset the password by performing Resetting the Password for a FlexusL Instance for logging in to the new OS. If you switch to an application image, reset the password only after the image with the pre-installed application is up and running, or the password reset may fail.
• Before using a private image, learn about the constraints on private images in Table 1 for FlexusL instances.

Preparations

Before batch OS changes, make the following preparations:

1. Prepare the COC FullAccess permissions.
   • If you are using a Huawei Cloud account, it has the COC FullAccess permissions by default. You can skip this step.
   • If you are an IAM user, a message is displayed, indicating that you do not have the required permissions. The account administrator needs to grant you the COC FullAccess permissions by doing the following:
     1. Grant a user group the COC FullAccess permissions. For details, see Creating a User Group and Assigning Permissions.
     2. Add the IAM user to the group. For details, see Adding Users to a User Group.
2. Apply for the COC open beta testing (OBT).

   COC is in the OBT phase. After you are granted the COC FullAccess permissions, apply for the COC OBT.

3. Synchronize FlexusL instance resources on the COC console.

   If you log in to the COC console for the first time, manually synchronize FlexusL instance resources. For details, see Synchronizing Resources.

   Figure 1 Synchronizing FlexusL instance resources
   
4. Before using a private image to change the OSs of FlexusL instances, use IMS to create an image first. A private image can be used by a FlexusL instance only after it is created using IMS. For more information, see Creating a FlexusL Instance from a Private Image or Using a Private Image to Change the OS.

Procedure

1. Log in to the FlexusL console, enable Batch operation, and click Batch Reinstalling OSs.

   If a message is displayed indicating that you do not have the required permissions or need to apply for the OBT, perform the operations described in Preparations first.

   Figure 2 Batch changing OSs
   
2. On the displayed page, configure parameters required for batch OS changes.
   Figure 3 Batch changing OSs
   

   Parameter	Description
   Target Instance	Selection Mode: Manual selection (only this option supported) Enterprise Project: All Resource Type: fixed to FlexusL, indicating that OSs are batch changed for FlexusL instances Region: Select the region where FlexusL instances are located. The instances must be in the same region. Batch OS change is not available for FlexusL instances in different regions. Target Instance: Select the FlexusL instances whose OSs are to be changed. If some FlexusL instances are missing in the list, synchronize resources first.
   Batch Policy	Select a batch policy based on your requirements. Automatic: The selected FlexusL instances are automatically divided into multiple batches based on the preset rule. Manual: You can manually create multiple batches and add FlexusL instances to each batch as required. No batch: All selected FlexusL instances will be executed in the same batch. NOTE: If you select Automatic or Manual and multiple batches of OS change tasks are generated, the process will be suspended after each batch of tasks is executed. You need to manually continue the next batch. For details, see Related Operations. If there are services running on your FlexusL instances, the No batch policy may affect your services. You are advised to select the automatic or manual batch policy.
   Suspension Policy	Determine the policy for suspending a task. You can set the success rate of OS reinstallation. When the success rate is lower than the specified value, the task status becomes abnormal and the task is suspended. The value is from 0 to 100 and can be accurate to one decimal place. Success rate = (Number of FlexusL instances whose OSs are successfully changed/Total number of FlexusL instances) x 100%
   Stop ECS	This option is displayed when there are FlexusL instances in Running state. Select Stop now.
   Image	Select an image that you want to switch to. FlexusL provides OS images, a rich variety of application images, and private images for you to select. Before using a private image to change the OSs of FlexusL instances, use IMS to create an image first. A private image can be used by a FlexusL instance only after it is created using IMS. For more information, see Creating a FlexusL Instance from a Private Image or Using a Private Image to Change the OS.

3. Click Submit. Confirm the information and click OK to start the OS change.

   After the request is submitted, the system generates a service ticket and you will be automatically redirected to the service ticket details page. You can also view the service ticket details later.

   After the OS is changed, the cloud server will automatically restart. When the server status is Running, the OS change is complete.

   NOTICE:

   • Do not reset the password of, restart, or stop the FlexusL instance immediately after the OS is changed. Wait for several minutes until the system successfully injects the password, or the login will fail.
   • After the OS is changed, the login password is cleared. You need to reset the password by performing Resetting the Password for a FlexusL Instance for logging in to the new OS. If you switch to an application image, reset the password only after the image with the pre-installed application is up and running, or the password reset may fail.

Related Operations

If you select Automatic or Manual and multiple batches of OS reinstallation tasks are generated, the process will be suspended after each batch of tasks is executed. Perform the following operations to manually continue the next batch of tasks:

1. Log in to the COC console.
2. Choose Task Management > Execution Records. On the Resource Operation Tickets tab, click the target service ticket ID.
   Figure 4 Viewing execution records
   
3. In the service ticket details on the displayed page, click Continue.
   Figure 5 Service ticket details