RHEL - For When Your Boss Asks 'What If This Breaks?'

RHEL is the Linux distro you choose when your boss asks "what happens if this breaks?" It's not exciting, but it works. Been around since 2003, which means it's survived multiple dot-com crashes, countless security scares, and the rise and fall of a dozen container orchestration platforms. That's staying power.

The Convert2RHEL tool exists because everyone's running CentOS and needs an escape plan. The process works about 70% of the time - have backups ready for when it doesn't.

That $800/year per server adds up real fast when you have 50+ boxes, but here's the thing: that subscription gets you 10 years of support for each major version. I've seen RHEL 6 systems still running in production because nobody wants to touch the upgrade. That's both the blessing and the curse of RHEL's lifecycle.

RHEL 10 hit GA on May 20, 2025 with this "Lightspeed" AI thing that's actually pretty clever. It helps junior admins figure out commands and troubleshoot issues without constantly bothering the senior staff. The AI isn't magic, but it beats having someone ask "how do I check disk usage" for the hundredth time.

SELinux comes enabled by default, which is RHEL's security system. It's incredibly powerful and will drive you insane for the first month until you learn how to configure it properly. Most people disable it, which defeats the point of using RHEL in the first place. Don't be that person - learn it or use Ubuntu.

The thing about Red Hat is they contribute heavily to upstream Linux projects, so features usually appear in Fedora first, get tested to death, then make it into RHEL 2-3 years later. This means RHEL is never cutting-edge, but it's also never surprising. When Red Hat says something works, it fucking works.

Red Hat Insights continuously analyzes your systems against the entire Red Hat knowledge base. It catches configuration drift and security issues before they bite you. I've seen it find memory leaks that would have taken down servers during peak traffic.

Live kernel patching sounds great until it fails and you need to reboot anyway. But hey, at least you tried to avoid the downtime. Setting up Satellite properly takes 2 weeks, not the 2 days Red Hat claims in their documentation.

RHEL won't impress anyone at conferences, but it's got features that justify the price tag if you're running actual production workloads.

SELinux: Your New Best Friend and Worst Enemy

SELinux comes enabled by default and will immediately break everything you try to deploy. This is actually good - it means your system is secure by default. The logs will fill up with denials faster than you can read them, but once you learn the basics (sealert -a /var/log/audit/audit.log is your friend), it becomes incredibly powerful.

I spent a weekend figuring out why my web app couldn't write to /tmp only to discover SELinux was doing its job. Took me 3 hours to realize I needed setsebool httpd_tmp_exec on. The alternative is running everything as root like a caveman.

The SELinux troubleshooting guide is actually readable, unlike most security documentation. It covers policy creation without the academic bullshit that usually accompanies security docs.

Red Hat Insights comes with your subscription and actually finds problems before they break things. It caught a memory leak in one of our Java apps that would have taken down the server during peak traffic. The remediation suggestions are hit-or-miss, but the problem detection is solid.

Performance Tuning That Actually Works

The tuned daemon actually optimizes your system based on workload instead of being marketing bullshit. Run tuned-adm profile throughput-performance and watch your database benchmarks improve. The profiles work about 80% of the time, which is better than manually tweaking kernel parameters and hoping for the best.

The performance tuning guide shows you what each profile actually does instead of magic button syndrome. Real-world benchmarks show 10-15% improvements for database workloads.

Live kernel patching with kpatch sounds amazing until you have that one patch that doesn't apply cleanly and you're back to scheduling maintenance windows at 2am. But when it works, it's magic. I've patched critical security vulnerabilities without downtime more times than I can count. Murphy's Law applies especially to kernel patches on production boxes.

Containers Done Right (Sort Of)

Podman is Red Hat's answer to Docker, and honestly, it's better for security. Rootless containers mean your app can't become root and pwn your entire system. The downside? Every Docker tutorial on the internet assumes you're using Docker, not Podman. alias docker=podman helps, but you'll still hit edge cases that make you want to just install Docker and be done with it.

The security advantages are real - no daemon running as root, better isolation. Benchmarks show similar performance to Docker with better memory usage. The rootless design eliminates entire classes of privilege escalation attacks.

Buildah for building container images is more powerful than docker build once you learn it, but the learning curve is steep. Most developers just want their Dockerfile to work, not learn a new build system.

The AI Thing (It's Actually Useful)

RHEL Lightspeed in RHEL 10 is basically ChatGPT for Linux commands. Sounds gimmicky, but it actually helps junior admins figure out complex one-liners without constantly asking senior staff.

Ask it "how do I find all files larger than 1GB modified in the last week" and it gives you the right find command with explanations. Beats having to remember man pages or Stack Overflow searches. The suggestions are right about 85% of the time, which is good enough for most tasks.