A one-line change to Kubernetes’ fsGroupChangePolicy cut the time spent waiting on restarts for Atlantis, the tool Cloudflare uses to plan and apply Terraform changes. According to The Cloudflare Blog, the root cause was a safe default that caused recursive chown operations on a very large persistent volume, slowing restarts from about 30 minutes to a crawl. By setting fsGroupChangePolicy to OnRootMismatch, the team stopped updating ownership on every mount, which reduced the restart time to roughly 30 seconds.
The result was a reclaiming of nearly 50 hours of blocked engineering time per month, equating to about 600 hours a year. The post notes that on smaller volumes the default is sensible, but as data grows it can become a bottleneck, and auditing securityContext settings such as fsGroup and fsGroupChangePolicy is worthwhile. In short, a single configuration tweak delivered a substantial efficiency gain and improved reliability for infrastructure changes at scale.