Understanding Local Groups in Computer Management
Open compmgmt.msc on any Windows server or workstation, expand Local Users and Groups, click Groups, and you see roughly 20 built-in local groups staring back at you. Each one bundles…
Tag: Permissions
Understanding NTFS Advanced Permissions
Click the Advanced button on any folder’s Security tab and you land in a different world. The everyday permissions — Full Control, Modify, Read & Execute, Write — vanish, replaced…
Windows File Permissions: Share vs NTFS Stacking
Every Windows admin runs into the same question on a file server: “I gave the user Full Control on the Security tab — why can’t they delete the file?” The…
The Five Golden Rules of Permissions Design
Every NTFS share, Active Directory OU, and file server eventually inherits the same mess: hundreds of access control entries that nobody can untangle, granted to people who left two years…
Linux File Permissions: chmod, chown, umask, and ACLs
Working reference for Linux file permissions. The 9-bit model (user/group/other times rwx), octal shorthand (r=4 w=2 x=1, classic 755 / 644 / 600 / 700 / 777-no-please), reading the ls -l first column for file types (-, d, l, c, b, s, p), chmod numeric vs symbolic syntax, the recursive-chmod foot-gun (use find -type f vs -type d separately, or X capital), chown / chgrp ownership changes, umask defaults (022 vs 027 vs 077), the three special bits (setuid 4 / setgid 2 / sticky 1) with /tmp and /usr/bin/passwd as examples, POSIX ACLs (setfacl -m u:bob:r--) for when 9 bits arent enough. Pitfalls: chmod -R 755 on code trees, SSH 600 / 700 requirements, web-server reading uploads, setuid on scripts (ignored), and what r/w/x actually mean for directories.