1.5 · File Sharing & Permissions

Goal: configure shared folders and permission levels appropriately.

Sharing methods

Method	Use
Windows file share (SMB)	Office LAN; mounted as a drive letter
NFS	Linux/Unix shares
NAS (Network Attached Storage)	Dedicated appliance — Synology, QNAP
Cloud (OneDrive, Google Drive, Dropbox)	Anywhere with Internet
WebDAV	HTTP-based file sharing

Permissions trio

Most filesystems express permissions as some combination of:

• Read (R) — view content.
• Write (W) — modify content.
• Execute (X) — run as a program (or open a folder).

Windows ACL

Granular rights: Full Control, Modify, Read & Execute, Read, Write. Per user or group.

Unix-style

Notation	Meaning
-rwxr-xr--	owner: rwx, group: r-x, others: r--
chmod 755 file	rwxr-xr-x
chmod 644 file	rw-r--r--
chown user:group file	Change owner/group

Best practices

1. Group users by role; grant permissions to the group, not individuals.
2. Least privilege — give the minimum needed.
3. Audit periodically — remove permissions for staff who have left.
4. Backups — sharing without backups is risky.
5. Encryption at rest — for sensitive folders.

Worked example · School shared drive

\\schoolfileserver\
├── Public  (Everyone: Read)
├── Teachers   (TeachersGroup: Read+Write)
├── Students   (StudentsGroup: Read; TeachersGroup: Read+Write)
└── Admin   (AdminGroup: Full Control)

A student opening Teachers folder gets "Access Denied". A teacher cannot delete the Admin folder.

Common student mistakes

• Granting "Everyone — Full Control" for convenience → catastrophic data loss potential.
• Confusing read (view file) with execute (open folder / run program).
• Leaving stale shares from past projects.

Exam-style question

Q (5 marks): Design permission settings for a school's shared drive with Public, Students, Teachers, Admin folders. Justify each choice.

Sample answer:

Folder	Group	Permission	Justification
Public	Everyone	Read	Bulletins / shared resources, no one should accidentally overwrite. Teachers may have Write to publish.
Students	StudentsGroup	Read; TeachersGroup: Read + Write	Students view assignments; teachers post & edit.
Teachers	TeachersGroup	Read + Write	Internal materials for staff collaboration; students excluded.
Admin	AdminGroup	Full Control	Sensitive HR / finance files; everyone else has no access.

This applies least privilege — each role can do only what it needs. Grouping by role keeps maintenance simple when staff change.

Key takeaways

• R / W / X (and finer ACLs in Windows).
• Group by role; least privilege.
• Audit, back up, encrypt sensitive folders.

Chapter 1 wrap-up

You've covered all the network-level skills needed for 2B. Time to write code.

➡️ Next chapter: 2 · Web Authoring