EX188 Container Operations And Lifecycle Practice Question
An administrator is working with a rootless Podman setup and needs to ensure that container user namespaces map UIDs correctly such that container root (UID 0) maps to the unprivileged user's UID on the host. Which file configures subordinate UID mappings for rootless users on RHEL?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
/etc/subuid and /etc/subgid
Rootless user namespaces rely on /etc/subuid and /etc/subgid for mapping ranges.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
/etc/subuid and /etc/subgid
Why this is correct
/etc/subuid and /etc/subgid define the subordinate user and group ID ranges allocated for user namespaces.
- ✗
/etc/containers/userns.conf
Why it's wrong here
This is not the standard file for host subuid allocations.
- ✗
/etc/security/limits.conf
Why it's wrong here
limits.conf is for PAM resource limits.
- ✗
/etc/passwd and /etc/group
Why it's wrong here
These define standard system accounts, not subordinate mapping ranges for containers.
About these practice questions
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official Red Hat exam blueprint
This EX188 practice question is part of Courseiva's free Red Hat certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the EX188 exam.