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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 example copy.

Command

BACKUP_ROOT=/srv/backups/site EXPECTED_CONFIG=/srv/backups/site/expected/app/config.yml RESTORE_SANDBOX=/tmp/linuxoneliners-restore/full && rm -rf "$RESTORE_SANDBOX" && mkdir -p "$RESTORE_SANDBOX" && tar -xf "$BACKUP_ROOT/2026-06-25/site.tar" -C "$RESTORE_SANDBOX" && diff -u "$EXPECTED_CONFIG" "$RESTORE_SANDBOX/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 example copy. Never point the rm -rf path at production data.

next steps

Related commands

Hosting Operations Deletes data

Check Required Files After Restore

A successful extraction still needs a required-file check.

BACKUP_ROOT=/srv/backups/site REQUIRED=/srv/backups/site/required-files.txt RESTORE_SANDBOX=/tmp/linuxoneliners-restore/full && rm -rf "$RESTORE_SANDBOX" && mkdir -p "$RESTORE_SANDBOX" && tar -xf "$BACKUP_ROOT/2026-06-25/site.tar" -C "$RESTORE_SANDBOX" && find "$RESTORE_SANDBOX" -type f | sed "s#^$RESTORE_SANDBOX/##" | sort | comm -23 "$REQUIRED" -
Hosting Operations Deletes data

Extract a Backup Into a Restore Sandbox

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

BACKUP_ROOT=/srv/backups/site RESTORE_SANDBOX=/tmp/linuxoneliners-restore/full && rm -rf "$RESTORE_SANDBOX" && mkdir -p "$RESTORE_SANDBOX" && tar -xf "$BACKUP_ROOT/2026-06-25/site.tar" -C "$RESTORE_SANDBOX"
Hosting Operations Deletes data

Verify Restored File Checksums

A restore is not validated until the bytes match.

BACKUP_ROOT=/srv/backups/site RESTORE_SANDBOX=/tmp/linuxoneliners-restore/full && rm -rf "$RESTORE_SANDBOX" && mkdir -p "$RESTORE_SANDBOX" && tar -xf "$BACKUP_ROOT/2026-06-25/site.tar" -C "$RESTORE_SANDBOX" && (cd "$RESTORE_SANDBOX" && 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.

BACKUP_ROOT=/srv/backups/site && tar -tf "$BACKUP_ROOT/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.

BACKUP_ROOT=/srv/backups/site REQUIRED=/srv/backups/site/required-files.txt && tar -tf "$BACKUP_ROOT/2026-06-24/site.tar" | sed 's#^./##' | sort | comm -23 "$REQUIRED" -
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.

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

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