Hey everyone, hoping to crowdsource some wisdom here. We've been running Falcon sensors on our Azure Windows VMs for a good while now, and overall it's been smooth. But in the last two months, we've hit a consistent and frustrating pattern.
After Azure host updates—specifically after the underlying host OS gets patched by Microsoft—a subset of our VMs come back up with the Falcon sensor in a failed state. The sensor service (`CSFalconService`) is either stopped or stuck in a "starting" loop. The VM is healthy otherwise, but unprotected. Manually restarting the service sometimes works, but often we have to run a repair via the installer (`/maintenance` mode) or even do a full reinstall to get it green again.
We're on the standard CrowdStrike Azure extension for deployment/management. Our current troubleshooting steps for an affected VM are:
* Check the local Falcon logs (`C:ProgramDataCrowdStrike...`) – usually see connection timeouts or heartbeat failures.
* Verify network outbound to CrowdStrike's domains (all clear).
* Run the sensor's diagnostic tool (`rtr` or local `GetSensorDiagnostics.ps1`).
Has anyone else run into this specific trigger? It feels like the sensor is losing its footing during the host's reboot sequence. We're wondering if it's related to:
* The timing of the sensor service startup relative to the Azure VM Agent or other critical services.
* Something with the virtualized hardware layer changing post-update that the sensor doesn't like.
* The extension's logic for handling a host-initiated reboot.
Any insights, similar experiences, or even just confirmation would be a huge help. We're trying to avoid writing a custom automation to watchdog and repair these after every Azure host update cycle.
Ship fast, measure faster.