I think my top ones are endpoint security software or running on redhat OSes. I used to work on a kubernetes distribution, so a large amount of the support esca

I think my top ones are endpoint security software or running on redhat OSes. I used to work on a kubernetes distribution, so a large amount of the support escalations and workload was around shipping kubernetes to customers who weren't as apt as the HN crowd. Endpoint Security Software, just because it's adding some policy, that usually isn't written by the team trying to run the application, and will apply the policy sometimes in non-obvious ways. Even when you think it's turned off, sometimes it isn't, and the vendor will leave kernel modules running and partial configurations. RedHat was more a result of the stability policy for kernel, and often running much older kernels then other distributions. We had lots of problems with the more modern kernel features used by kubernetes, that we had to track down and often link to known fixes. We had one customer even replacing their kernels so they wouldn't have as many issues. This may be less and less of the case all the time with newer RedHAt Releases, and I also have no reason to believe OpenShift suffers in the same way... just that I've spent a large amount of time troubleshooting this.