Entering

“Red Hat or Ubuntu?” is a question that every organization that runs Linux servers inevitably encounters. It's not just a matter of preference, but decisions that directly impact the business, including license costs, technical support SLAs, security patch cycles, certification/compliance, and talent pool.

In this article, we compare the RHEL (Red Hat Enterprise Linux) series and Ubuntu Server from an enterprise operation perspective and organize recommendation criteria for each workload.

1. Distribution lineage and current ecosystem

Red Hat family

Fedora (업스트림) → RHEL (엔터프라이즈) → CentOS Stream (중간 스트림)
→ Rocky Linux (커뮤니티 RHEL 클론)
→ AlmaLinux (커뮤니티 RHEL 클론)

• RHEL: Red Hat subscription required. Technical support for over 10 years.
• CentOS Stream: Preview of RHEL's next minor release. Direct production use is debated.
• Rocky Linux / AlmaLinux: 1:1 RHEL compatible distribution that appeared after CentOS 8 support ended.

Debian series

Debian (업스트림) → Ubuntu (Canonical) → Ubuntu LTS (장기 지원)
                                       → Ubuntu Pro (확장 보안)

• Ubuntu LTS: Releases every 2 years, 5 years base + 10 years support for Ubuntu Pro.
• Ubuntu Pro: Canonical's enterprise security and compliance product.

2. Key comparison table

3. Package management comparison

DNF (Red Hat family)

# 패키지 검색·설치·제거
dnf search nginx
dnf install -y nginx
dnf remove nginx

# 패키지 정보·파일 목록
dnf info nginx
rpm -ql nginx

# 보안 업데이트만 적용
dnf update --security

# 모듈 스트림 (RHEL 8+)
dnf module list nodejs
dnf module enable nodejs:20
dnf module install nodejs:20/common

# 트랜잭션 이력·롤백
dnf history
dnf history undo 15

# 저장소 관리
dnf repolist
dnf config-manager --add-repo https://repo.example.com/el9/

APT (Ubuntu)

# 패키지 검색·설치·제거
apt search nginx
apt install -y nginx
apt remove nginx
apt purge nginx  # 설정 파일까지 삭제

# 패키지 정보·파일 목록
apt show nginx
dpkg -L nginx

# 보안 업데이트만 적용
apt update
apt upgrade -y -o Dpkg::Options::="--force-confold"  # 기존 설정 유지
# 또는 unattended-upgrades 활용

# 자동 보안 업데이트 설정
apt install unattended-upgrades
dpkg-reconfigure -plow unattended-upgrades

# PPA 관리
add-apt-repository ppa:deadsnakes/ppa
apt update

# 버전 고정
apt-mark hold nginx
apt-mark unhold nginx

Package Management Comparison Summary

4. Security model comparison

SELinux (RHEL family)

Based on MAC (Mandatory Access Control), the files, ports, and system calls that a process can access are limited by policy.

# 상태 확인
getenforce          # Enforcing / Permissive / Disabled
sestatus            # 상세 상태

# 컨텍스트 확인
ls -Z /var/www/html
ps -eZ | grep nginx

# 불리언 토글
getsebool -a | grep httpd
setsebool -P httpd_can_network_connect on

# 문제 진단
ausearch -m avc -ts recent
sealert -a /var/log/audit/audit.log

# 커스텀 정책 모듈
audit2allow -a -M my_policy
semodule -i my_policy.pp

AppArmor (Ubuntu)

Path-based MAC defines access rights for each program through a profile file.

# 상태 확인
aa-status
apparmor_status

# 프로필 모드 전환
aa-enforce /etc/apparmor.d/usr.sbin.nginx
aa-complain /etc/apparmor.d/usr.sbin.nginx

# 로그 기반 프로필 생성
aa-genprof /usr/sbin/myapp
aa-logprof

Security model comparison

Practical Advice: SELinuxDisabledTurning it off is an anti-pattern. If there's a problemPermissiveSwitch to and analyze the logs to adjust the policy.

5. System management command mapping

6. Containers and cloud native

Container base image

| Item | UBI 9 (Red Hat) | ubuntu:24.04 | | ---------------------- | ------------------------ | -------------------------------- | ------------- | | image size | ~215MB | ~78MB | | Minimal transformation | ubi9-minimal(~100MB) | ubuntu:24.04itself lightweight | | Micro variant | ubi9-micro(~35MB) | - | | Redistribution | Freedom (UBI EULA) | freedom | | security scan | Red Hat Vulnerability DB | Canonical USN | | package manager | microdnf/dnf | apt | ```dockerfile |

RHEL 계열 멀티스테이지

FROM registry.access.redhat.com/ubi9/ubi-minimal:latest AS builder RUN microdnf install -y java-17-openjdk-headless && microdnf clean all COPY target/app.jar /app.jar

FROM registry.access.redhat.com/ubi9/ubi-micro:latest COPY --from=builder /usr/lib/jvm /usr/lib/jvm COPY --from=builder /app.jar /app.jar ENTRYPOINT ["java", "-jar", "/app.jar"]

`

dockerfile
# Ubuntu 멀티스테이지
FROM ubuntu:24.04 AS builder
RUN apt-get update && apt-get install -y --no-install-recommends \
    openjdk-17-jre-headless && rm -rf /var/lib/apt/lists/*
COPY target/app.jar /app.jar

FROM gcr.io/distroless/java17-debian12
COPY --from=builder /app.jar /app.jar
ENTRYPOINT ["java", "-jar", "/app.jar"]
```### Kubernetes Compatibility

Both distributions fully support Kubernetes. The difference mainly appears in the **Managed Service Base OS**.

| Cloud | Managed K8s Node Base OS |
| ------------- | ----------------------------------------------- |
| **AWS EKS** | Amazon Linux 2023 (RHEL family) / Bottlerocket |
| **Azure AKS** | Ubuntu (default) / Azure Linux (CBL-Mariner) |
| **GCP GKE** | Container-Optimized OS (Chromium-based) / Ubuntu |

---

## 7. Comparison of license, cost, and support

| Item | RHEL | Rocky Linux | Ubuntu LTS | Ubuntu Pro |
| ------------- | --------------------- | ---------------- | ------------- | ------------------------------ |
| License Fee | $799~$13,000+ per year | Free | Free | Free for small, paid for enterprise |
| Technical Support | Red Hat 24/7 | Community | Community | Canonical 24/7 |
| SLA | 1-4 hour response | None | None | 1 hour response |
| security patch | Red Hat Security | RHEL Synchronization | Canonical USN | Extended Security (12 years) |
| Compliance | FIPS, CC, STIG, HIPAA | FIPS (Self-Certified) | CIS | FIPS, CIS, DISA-STIG |
| Training/Certification | RHCSA, RHCE | - | - | CUA (Canonical) |

### Actual cost simulation (based on 100 servers)

| Scenario | Annual Cost (estimated) |
| ---------------------------- | ------------------- |
| RHEL Standard (100 units) | $80,000~$130,000 |
| Rocky Linux + external technical support | $20,000~$50,000 |
| Ubuntu LTS (Community) | $0 (excluding personnel costs) |
| Ubuntu Pro (100 units) | $25,000~$50,000 |

---

## 8. Recommendations by workload| workload | Recommended Distributions | Evidence |
| ------------------------- | ----------------- | ---------------------------------- |
| **Finance/Medical (Regulated Industry)** | RHEL | FIPS/CC/STIG certification, audit history |
| **SAP / Oracle DB** | RHEL | Official vendor support |
| **Startup Web Service** | Ubuntu LTS | Community·Latest Package·Cost |
| **Kubernetes workload** | Ubuntu or Rocky | Cloud native ecosystem |
| **ML/AI workload** | Ubuntu | Priority support for NVIDIA drivers and CUDA |
| **Legacy Java Services** | RHEL/Rocky | JBoss/WildFly Certification |
| **CI/CD Runner** | Ubuntu | GitHub Actions, GitLab Runner Basics |
| **Internal Tools Server** | Rocky/AlmaLinux | RHEL Compatible + Free |

---

## 9. Migration Checklist

### CentOS → Rocky Linux / AlmaLinux```bash
# Rocky Linux 마이그레이션 (in-place)
curl -O https://raw.githubusercontent.com/rocky-linux/rocky-tools/main/migrate2rocky/migrate2rocky.sh
chmod +x migrate2rocky.sh
./migrate2rocky.sh -r  # 변환 실행

# 검증
cat /etc/os-release
rpm -qa | grep rocky
dnf check

Things to check when switching from Ubuntu ↔ RHEL

10. Decision-making flowchart

조직에 규제 컴플라이언스(FIPS, CC, STIG) 요구사항이 있는가?
├── Yes → RHEL (또는 Ubuntu Pro FIPS)
└── No
    ├── 벤더 인증이 필요한 상용 소프트웨어를 운영하는가? (SAP, Oracle 등)
    │   ├── Yes → RHEL
    │   └── No
    │       ├── 24/7 벤더 기술 지원이 필요한가?
    │       │   ├── Yes + 예산 있음 → RHEL 또는 Ubuntu Pro
    │       │   └── No
    │       │       ├── RHEL 호환이 필요한가? (사내 RPM, 기존 인프라)
    │       │       │   ├── Yes → Rocky Linux / AlmaLinux
    │       │       │   └── No → Ubuntu LTS
    │       │       └──
    │       └──
    └──

Finish

There is no "best distro". The distribution that fits your organization's regulatory requirements, technical capabilities, budget, and existing infrastructure is the right choice. The key points are three things:

1. If compliance is required RHEL is the safest choice.
2. If you want RHEL compatibility while reducing costs, consider Rocky/AlmaLinux.
3. If you want a modern ecosystem and vibrant community Ubuntu LTS makes sense.

No matter which distribution you choose, patch management, security policies, and automation are basic skills that you must have regardless of the distribution.

Quiz