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Hosting Operations

Deletes or truncates files

Diff Restored Config Against Expected

You need to compare a restored configuration file with the expected fixture copy.

Command

cd restore-dr && rm -rf restore-sandbox/full && mkdir -p restore-sandbox/full && tar -xf backups/2026-06-25/site.tar -C restore-sandbox/full && diff -u expected/app/config.yml restore-sandbox/full/app/config.yml

Before you run this

System impact: Deletes, truncates, or overwrites data. Requires backup, preview, and exact path review before production use.

When not to use it: Do not diff secrets into public logs; choose non-sensitive config or redact first.

Expected output

No diff output when the restored config matches expected.

System impact

Deletes or truncates files. The existing restore-sandbox/full directory is removed and recreated; diff then reads the restored and expected config files.

When to use it

Use when restored configuration must match a known-good expected file.

When not to use it

Do not diff secrets into public logs; choose non-sensitive config or redact first.

Recovery / rollback

Remove the restore-dr/restore-sandbox/full directory from the fixture copy. Never point the rm -rf path at production data.

Watch this command run

Example output from a temporary Linux lab

This example uses disposable sample files and sanitized output so you can inspect the shape of the result before touching a real system.

demo@lab:~$

$ cd restore-dr && rm -rf restore-sandbox/full && mkdir -p restore-sandbox/full && tar -xf backups/2026-06-25/site.tar -C restore-sandbox/full

$ cd restore-dr && diff -u expected/app/config.yml restore-sandbox/full/app/config.yml

View reproducible demo details

These commands recreate the temporary example before running the command under review.

Reproduce this demo

  1. cd restore-dr && rm -rf restore-sandbox/full && mkdir -p restore-sandbox/full && tar -xf backups/2026-06-25/site.tar -C restore-sandbox/full
  2. cd restore-dr && diff -u expected/app/config.yml restore-sandbox/full/app/config.yml

next steps

Related commands

Hosting Operations Deletes data

Check Required Files After Restore

A successful extraction still needs a required-file check.

cd restore-dr && rm -rf restore-sandbox/full && mkdir -p restore-sandbox/full && tar -xf backups/2026-06-25/site.tar -C restore-sandbox/full && find restore-sandbox/full -type f | sed 's#^restore-sandbox/full/##' | sort | comm -23 required-files.txt -
Hosting Operations Deletes data

Extract a Backup Into a Restore Sandbox

A restore drill should write to a sandbox, not production.

cd restore-dr && rm -rf restore-sandbox/full && mkdir -p restore-sandbox/full && tar -xf backups/2026-06-25/site.tar -C restore-sandbox/full
Hosting Operations Deletes data

Verify Restored File Checksums

A restore is not validated until the bytes match.

cd restore-dr && rm -rf restore-sandbox/full && mkdir -p restore-sandbox/full && tar -xf backups/2026-06-25/site.tar -C restore-sandbox/full && (cd restore-sandbox/full && sha256sum -c CHECKSUMS.sha256)
Hosting Operations Read-only

List Archive Contents Before Extracting

You can inspect a tar backup before it writes a single file.

cd restore-dr && tar -tf backups/2026-06-25/site.tar | sed 's#^./##' | sort
Hosting Operations Read-only

Find Missing Files in an Old Backup

The fastest failed restore drill is the one that finds missing critical files early.

cd restore-dr && tar -tf backups/2026-06-24/site.tar | sed 's#^./##' | sort | comm -23 required-files.txt -
Study mapping

Use this as independent command practice: read the notes, predict the output, then compare it with the example before using a real shell.

  • lpic1:103-gnu-unix-commands
  • lpic1:104-filesystems-permissions-fhs
  • lfcs:essential-commands
  • lfcs:operations-deployment
  • lfcs:services-logs
  • lfcs:storage
  • linuxplus:automation-scripting
  • linuxplus:provisional
  • linuxplus:troubleshooting
  • risk:production-state-change

Useful for

  • LPIC-1 style command-line practice
  • LFCS style performance tasks
  • Linux+ style troubleshooting review

Independent study support only. No affiliation, endorsement, exam dumps, or real exam questions.