Migrating to Azure VMware Solution moves your virtual machines without moving the assumptions built around them. Those assumptions came from a data center where your team controlled the hardware, knew the maintenance windows, and could walk to the rack.

The workloads that end up here are usually the oldest and least understood in the estate. They were lifted rather than rewritten because rewriting wasn't viable, their documentation is thin, and the engineers who built them have moved on. They've been reliable, so nobody looked closely.

Gremlin gives you a current picture instead of a six-year-old runbook. Install the Gremlin Agent on guest VMs in your private cloud, then run Shutdown experiments to establish what actually happens when one fails: what recovers on its own, what needs a human, and how long each takes. CPU and memory experiments surface contention between co-located workloads that your monitoring tools were never configured to catch.

For applications that are business-critical and poorly understood, that baseline is worth having before you decide whether to modernize them or retire them.