@Sarkar, Shalini
I understand you are wanting more information on update management for your custom RHEL VM.
Please see this page for detailed information on Update Management in Azure Automation. There is also a step-by-step tutorial on how to accomplish this for Linux VMs. Some additional options and features to consider are Automatic VM guest patching. This is an alternative update management solution for your Azure VMs to auto-update them during off-peak hours, including VMs within an availability set, compared to managing update deployments to those VMs from Update Management in Azure Automation. As well as automatic OS image upgrades.
Hope this helps you get started! Let me know if there are additional questions or features you need help with.
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