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Unofficial practice

Rsync Dry-Run Backup

A backup or archive command is about to move data. Preview the file set and deletion behavior before running a write.

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Try first

rsync -avhn --delete /srv/app/ /backup/app/

Troubleshooting ladder

  1. Name the symptom.
  2. Inspect read-only state.
  3. Find the owner, service, file, device, mount, or route.
  4. Read the decisive output field.
  5. Choose the next narrow command.
  6. Avoid broad or destructive changes.
  7. Make the smallest justified change if required.
  8. Verify and record what changed.

drill evidence

Sample output and answer key

Command anatomy

rsync -avhn --delete /srv/app/ /backup/app/
rsync/tar
inspect or preview archive and backup movement
dry-run/list flag
prove the file set before writing
source
where data comes from
destination/archive
where data would go or be restored from

Annotated output

sending incremental file list
.d..t...... ./
>f+++++++++ releases/app.tar.gz
>f.st...... current/config.yml

sent 2.1K bytes  received 82 bytes  4.3K bytes/sec

What to notice

itemize flag
what rsync would change
path
which file would move
sent/received
how large the planned transfer looks

Safe vs unsafe move

Common wrong move

Running without dry-run before checking whether --delete would remove files.

Next safe command

rsync -avhn --delete /srv/app/ /backup/app/ | sed -n '1,40p'

Goal

Prove the condition with command output before changing the system.

Safe first command

rsync -avhn --delete /srv/app/ /backup/app/

Correct interpretation

The decisive fields are `itemize flag`, `path`, `sent/received`. The affected object is the path, user, address, or package named by the command output. The next safe command is `rsync -avhn --delete /srv/app/ /backup/app/ | sed -n '1,40p'` because it narrows the evidence without jumping to a broad fix. Watch out for this wrong move: Running without dry-run before checking whether --delete would remove files.

Next safe command

rsync -avhn --delete /srv/app/ /backup/app/ | sed -n '1,40p'

Common wrong move

Running without dry-run before checking whether --delete would remove files.

Self-check

Which listed path would be copied or deleted, and what dry-run line proves it?

source and objective

Related cert objective

Source status: Linux Foundation LFCS page verified June 30, 2026. LFCS is an online, proctored, performance-based command-line exam.

Open related practice area

Related command pages

Why this matters

The point is not to memorize a flag. It is to read the evidence, name the next safe check, and avoid the tempting broad fix.