Package/process ops · Lesson 10 of 20 · 8 minutes

Package and process checkpoint

Review packages, process state, and recent package logs.

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Your objectives

Hints are always available. Wrong turns never cost XP.

1
List packages
Run apt list --installed.
Hint & worked example
Inspect a fixed training package inventory. The simulator cannot install or upgrade your computer.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
apt list --installed
```
Remember: Candidate, installed, and repository versions answer different questions.
2
List dpkg packages
Run dpkg -l.
Hint & worked example
Inspect installed-package records in the synthetic Debian-style environment.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
dpkg -l
```
Remember: Repository availability and installed package state are separate evidence.
3
Read process snapshot
Run top.
Hint & worked example
Inspect a single training snapshot of process and resource activity.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
top
```
Remember: This lab does not run a continuously refreshing process monitor.
4
Find upgrade log
Run grep upgrade /var/log/dpkg.log.
Hint & worked example
Select input lines that match a pattern; -i ignores case, -n adds line numbers, and -v inverts selection.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
grep upgrade /var/log/dpkg.log
```
Remember: No matches is exit status 1, which is different from a malformed invocation.

Understand the pattern

Junior operators build confidence by gathering evidence before changing systems.

apt: Inspect a fixed training package inventory. The simulator cannot install or upgrade your computer.
Candidate, installed, and repository versions answer different questions.
dpkg: Inspect installed-package records in the synthetic Debian-style environment.
Repository availability and installed package state are separate evidence.
top: Inspect a single training snapshot of process and resource activity.
This lab does not run a continuously refreshing process monitor.
grep: Select input lines that match a pattern; -i ignores case, -n adds line numbers, and -v inverts selection.
No matches is exit status 1, which is different from a malformed invocation.

Worked example and expected result

$ apt list --installed

fake-nginx/learn 1.0 installed
fake-openssh/learn 9.9 installed
coreutils/learn 9.5 installed

Exit status: 0. The command completed successfully in the training fixture.

$ dpkg -l

ii  fake-nginx     1.0  training web server
ii  fake-openssh   9.9  training ssh server
ii  coreutils      9.5  training utilities

Exit status: 0. The command completed successfully in the training fixture.

$ top

top - 10:26:04 up 12 days, 1 learner, load average: 0.04, 0.03, 0.01
PID USER      %CPU %MEM COMMAND
42  www-data   0.2  1.1 nginx
77  root       0.1  0.8 sshd
126 root       0.0  0.3 cron

Exit status: 0. The command completed successfully in the training fixture.

$ grep upgrade /var/log/dpkg.log

2026-05-26 08:01:00 upgrade fake-openssh 9.9

Exit status: 0. The command completed successfully in the training fixture.

Try a variation

Repeat this workflow in the sandbox with a different scratch filename. Keep the system fixtures unchanged and compare the observed output with your expectation before moving on.

Explain it

In “Package and process checkpoint”, which interpretation is safe?Repository availability and installed package state are separate evidence.A command appearing in history proves it completed successfully.A successful first check guarantees that every dependent service is healthy.

Apply it elsewhere

Before adapting the dpkg workflow from “Package and process checkpoint” to another server, what should you do?Paste the training paths unchanged into production.Skip output inspection whenever the command is familiar.Confirm the current directory, target identity, permissions, and the installed command behavior first.

Keep the momentum.

Complete the lab, then explain and apply the pattern.

Next: APT DPKG Brew compare Try an incident drill

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