Hosting Operations
Read-only, can be slowVerify a SHA256 Checksum Manifest
You need to confirm files still match a saved SHA256 manifest.
Command
sha256sum -c checksums.sha256Before you run this
System impact: Read-only. Can create load on large logs, directories, filesystems, or process tables.
When not to use it: Do not use it if the checksum manifest came from an untrusted source.
Expected output
One OK line per verified file.
System impact
Read-only, can be slow. Nothing changes. The command reads files and checks hashes against the manifest.
Scope this to the smallest useful path or service on busy systems.
Recovery / rollback: no state is changed.
When to use it
Use after copying, restoring, or unpacking files from a backup.
When not to use it
Do not use it if the checksum manifest came from an untrusted source.
Watch this command run
Command transcript
This sanitized transcript shows the commands and output shape without exposing host details.
$ sed -n '1,4p' checksums.sha256
5a453a017f0c3bfb78e8205c21f7fcba3e26b1cc406b48664217931d26c1c50d source/app/config.yml
5836e81dfa7b529b8773edf3addc5a43e3397d0bf8afc1534728f5090e7b2a5f source/content/index.md
1dc8e74b2fc81bc174426952064e702cd22719d42ae1290df8f5081df42a758f source/content/about.md
6d6ddf6160dbd0685f29b421c8f85ad7ae4e7c6eb12ef9987cc699c7debd046a source/assets/logo.svg$ sha256sum -c checksums.sha256
source/app/config.yml: OK
source/content/index.md: OK
source/content/about.md: OK
source/assets/logo.svg: OKView commands shown
These are the commands shown in the sanitized transcript.
Commands shown
sed -n '1,4p' checksums.sha256sha256sum -c checksums.sha256
next steps
Related commands
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)
Create a SHA256 Checksum Manifest
A file list says what exists; checksums say whether bytes match.
sha256sum source/app/config.yml source/content/index.md source/content/about.md source/assets/logo.svg
Compare Artifact Checksums
Verify two artifact copies match before blaming deployment code.
sha256sum artifacts/app.tar.gz releases/current/app.tar.gz
Compare Source and Backup File Lists
A backup can be missing files and still look plausible at a glance.
comm -3 <(find source -type f | sed 's#^source/##' | sort) <(find backup -type f | sed 's#^backup/##' | sort)
Check Whether Expected Build Outputs Exist
The deploy failed because the build never produced the file.
find artifacts/dist -maxdepth 2 -type f | sort
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.
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.