@Kishore-Reddy.Byreddy Thanks for posting your query on Microsoft Q&A.
As per the official Microsoft documentation, if maintenance requires a reboot, you're notified of the planned maintenance. Azure also provides a time window in which you can start the maintenance yourself, at a time that works for you. Based on the notification you have shared; it looks like a planned maintenance that requires a reboot to be performed on few servers in your subscription.
#Maintenance that requires a reboot
In cases where VMs need to be rebooted for planned maintenance, you'll be notified in advance. Planned maintenance has two phases: the self-service phase and a scheduled maintenance phase. Currently, you are in self-service phase. During the self-service phase, which typically lasts four weeks, you start the maintenance on your VMs. As part of the self-service, you can query each VM to see its status and the result of your last maintenance request. When you start self-service maintenance, your VM is redeployed to an already updated node. Because the VM is redeployed, the temporary disk is lost and dynamic IP addresses associated with the virtual network interface are updated. If an error arises during self-service maintenance, the operation stops, the VM isn't updated, and you get the option to retry the self-service maintenance. When the self-service phase ends, the scheduled maintenance phase begins. During this phase, you can still query for the maintenance phase, but you can't start the maintenance yourself.
#Handling planned maintenance notifications using the portal
Once a planned maintenance wave is scheduled, you can check for a list of virtual machines that are impacted using the Azure CLI, PowerShell or portal. Click on the maintenance notification to see the maintenance page with more details on the planned maintenance. From there, you will be able to start maintenance on your VM. Once you start maintenance, your virtual machine will be maintained and the maintenance status will be updated to reflect the result within few minutes. If you missed the self-service window, you will still be able to see the window when your VM will be maintained by Azure.
#To prepare for VM maintenance and reduce impact during Azure maintenance,
- Try using Scheduled Events for Windows or Linux for such applications.
- For greater control on all maintenance activities including zero-impact and rebootless updates, you can create a Maintenance Configuration feature. Creating a Maintenance Configuration gives you the option to skip all platform updates and apply the updates at your choice of time. For more information, see Managing platform updates with Maintenance Configurations.
#This document covers the maintenance process in detail. I would recommend going through the whole document to get a better understanding of the process.
Hope that helps.
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