Hi @Souomou Aimé, B2B-BPN-HLT-DO-ENG ,
You could create an alert from "Alerts" tile under your linux Azure VM by clicking on "+Create" -> "Alert rule" -> "See all signals" -> type "free" in the search box as shown in below screenshot and then click "Apply" and then provide required threshold value as per your need under alert logic and create alert rule by following next steps as required. Let me know if you have any further queries.