Managing Users and Permissions on Linux the Right Way

I used to treat Linux permissions like an annoying warning I had to get around.

“Oh, permission denied? Just slap a chmod 777 on it and move on.”

Yeah… I’ve been that person. 😅

It wasn’t until I accidentally gave full write access to a shared directory (and someone deleted half the files) that I realized: Linux permissions are not optional. They’re essential.

Here’s how I learned to manage users and permissions the right way — and the lessons that stuck.

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Lesson 1 — Not Everyone Needs to Be sudo

When I first started managing a team server, I gave everyone sudo access because it was “easier.”

Big mistake.

Now? I follow this rule:

Only give sudo to people who absolutely need it.
Everyone else gets their own user account, with just the permissions they need.

adduser devuser

Want to give sudo?

usermod -aG sudo devuser

Don’t want to? Just leave them as-is. It’s safer.

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Lesson 2 — Use Groups Like a Pro

Linux has this beautiful concept called groups — and I ignored it for years.

Now, I structure access like this:

• Group: webdev → for people who manage web files
• Group: dbadmin → for those who handle databases
• Group: media → for uploading and media content

groupadd webdev
usermod -aG webdev alice
usermod -aG webdev bob

Then I set folder ownership like this:

chown -R root:webdev /var/www/html
chmod -R 770 /var/www/html

Boom — only webdev group members can touch it.

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Lesson 3 — Know Your chmod

Here’s the simple mental model I use now:

• 7 = read + write + execute
• 6 = read + write
• 5 = read + execute
• 4 = read only
• 0 = no access

When setting permissions, think:

chmod 750 filename

That means:

• Owner: full access
• Group: read + execute
• Others: no access

This one habit saved me from so many “oops” moments.

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Lesson 4 — Sticky Bit for Shared Folders

Ever needed a shared directory where users can write, but only delete their own files?

Enter the sticky bit:

chmod +t /shared/folder

Now, even if multiple users can write to the same folder, they can’t delete each other’s files. Clean and safe.

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Lesson 5 — Audit Regularly

Every month or so, I run a little audit:

getent passwd | grep /home

This shows all users with home directories (i.e., human users). I check if any are no longer in use.

And for permissions, I use:

ls -l /some/folder

If I see anything like -rwxrwxrwx (aka 777) — red flag.

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Final Thought

Managing users and permissions isn’t just for big companies or security freaks. It’s part of running a responsible Linux environment.

The good news? You don’t need to be an expert. Just start small:

✅ Create users properly
✅ Use groups intentionally
✅ Set correct permissions
✅ Review regularly

Once I embraced this mindset, my server stopped feeling like a messy junk drawer and started feeling like a system I could trust.