prlimit tips — authorized resource-limit literacy

Snapshot

Tip checklist (authorized only)

1. Confirm you may run prlimit on the lab host (syllabus box you own or were given access to).
2. Prefer documenting who / why / ticket before any limit change — never poke production without change control.
3. Record short factual notes; quote short Evidence (soft/hard labels — never secrets from target processes).
4. Optional: shell peer → ulimit-resource-tips.
5. Optional: scheduler/timeout peers → nice-tips / timeout-cmd-tips.
6. Prefer disposable lab PIDs for prlimit drills; quote non-secret labels afterward as Evidence.
7. Prefer read-only --pid inspect modes for most Evidence binders unless the syllabus asks for write drills.
8. Stop at literacy — no attack or unauthorized denial-of-service cookbooks.

Allowed framing

• Classroom labs reviewing prlimit on authorized disposable processes (prlimit --pid soft/hard read-backs).
• Binding short factual notes as Evidence (RLIMIT labels — no secrets).
• Documenting expected vs observed resource-limit literacy for authorized inventory notes.
• Comparing prlimit ↔ peer tip pages under one binder.
• Testing limit writes only when the syllabus authorizes that drill on lab resources.

Scope we will not cover

• No crack/pirate/keygen via prlimit.
• No intentional unauthorized resource exhaustion against foreign hosts.
• No secret-theft or credential harvesting via process inspect on hosts you do not own.
• No cookbooks that weaken cgroup/quota controls on foreign hosts without authorization.

Beginner path (authorized only)

1. Obtain one syllabus-approved disposable lab host with a usable prlimit toolchain.
2. Prefer a throwaway lab process before any write drill.
3. With authorization, run a syllabus-approved prlimit --pid <lab-pid>; quote soft/hard labels as Evidence.
4. Optional: peer tip pages above when the syllabus asks.
5. Stop at literacy — no attack or unauthorized DoS cookbooks.

Practical notes for authorized labs

• prlimit reads/writes RLIMIT soft/hard pairs per PID — keep Evidence labels distinct from shell ulimit-resource-tips.
• Pair with systemd-run-tips only for syllabus-approved transient unit limit literacy on lab hosts.
• Target process command lines may embed secrets — never paste them into notes or git.
• Prefer documenting RLIMIT names and values the syllabus authorized without dumping full /proc secret context.
• Never commit prlimit dumps with secrets to git — even for labs.

FAQ

Sources