linuxmemes

One of our servers is a rotting carcass being kept alive by our collective prayers. It runs Windows 7 and custom software whose developer is dead and the source is missing, nothing has been updated for over a decade, and it has its own independent UPS because once it goes down, it has an extremely slim chance of recovering, and we're afraid to test it. It controls the card entry system into the building, including the server room. Boss doesn't want to replace it because we'd have to replace all of the terminals and controllers too, and it hasn't catastrophically failed yet.

You're right. It's not a pet. It's like one of the Saw movies: if it dies, we're all fucked.

I learned this relatively quickly running my own server with the intention of my family also using it. Data on a separate drive, backed up regularly and automatically. System on it's own drive, dd'd when it's in it's final state and backed up before I screw around any deeper than trying out a new container. I can bring my server back up in however long it takes to transfer data.

• sudo is telling the computer to do this with root privileges.
• chmod sets permissions.
• Each digit of that three-digit number corresponds to the owner, the group, and other users, respectively. It's 0–7, where 0 means no access and 7 means access to read, write, and execute. So 077 is the exact inverse of 700, where 077 means "the owner cannot access their own files, but everyone else can read, write, and execute them". Corresponding 700 to asexuals is joking that nobody but the owner can even so much as touch the files.
• / is the root directory, i.e. the very top of the filesystem.
• The -R flag says to do this recursively downward; in this case, that's starting from /.

So here, we're modifying every single file on the entire system to be readable, writable, and executable by everyone but their owner. And yes, this is supposed to be extremely stupid.

7 is read, write, and execute permissions. 700 is owner, but not group or others. 077 means the owner has no permissions, but group and others all have full permissions.

File permissions...

allowed to execute=1, allowed to write=2, allowed to read=4

grouped by owner/group/everyone.

So one of your own files you have full access to while users in your usergroup are only allowed to read it and nobody else has any permissions would have: 740 (read+write+execute / read / none).

Good catch - I should have said that it's closer to Windows-style ACLs rather than implying that it's actually the same.