For what it's worth I had asked someone the very same question when I started my career.

From the horses mouth take a look at ext4 on ubuntu https://help.ubuntu.com/community/LinuxFilesystemsExplained

Then a 10,000 mile view, I'd take a look at UNIX and Linux https://www.amazon.com/UNIX-Linux-System-Administration-Hand...

There are more books I could list and papers on FileSystems. I will leave you with three particular books that have guided my career

If you want to look solely at Ubuntu. The Ubuntu Server book https://www.amazon.com/Official-Ubuntu-Server-Book-3rd/dp/01...

Unix Made Easy - https://www.amazon.com/UNIX-Made-Easy-John-Muster/dp/0072193...

Hope this helps

Might as well add a link to a book I learned about on HN but never seem to run across since, UNIX and Linux System Administration Handbook, 4th Edition: http://www.amazon.com/Linux-System-Administration-Handbook-E...

I'm willing to bet there isn't but a handful of people in this community that "knows everything on that list", remembering everything on that list is... well, unneeded?

9/10 times when I'm using a command that isn't part of my "daily list" I'll need to consult man pages and/or Google.

I've used xargs hundreds of times, but depending on when I used it last, I can never remember if I need -0 or not, and is it $1 or {} or wait, no no, I'm using awk, so it's $1, and I need to changes something... is it needle, haystack, replacement or... hell, I'm not even sure if it's substr or just sub... errrr.

Not to mention some of these are distro specific, in some you use service name start, in others it's /etc/init.d/service start. Some it's adduser, others it's useradd, etc. It's relative to the distro a lot of the times... are the files in /usr/opt/ or /opt/... or maybe they're in /usr/local/opt/... Also they list stuff like locate, but not updatedb. Not a single mention of dd or shred or /etc/resolv.conf or netcat (I fucking love netcat!) or unzip (far more likely to need to unzip an archive than add a user in your day to day life).

We're not command libraries, we're duct tape mechanics.

http://xkcd.com/1168/

edit: if you're interested in learning more... I honestly can't recommend this book enough.

http://www.amazon.com/Linux-System-Administration-Handbook-E...

Wow, this is a great approach you've chosen, and it will teach you a ton. If you want to start learning more about how your machine is configured, the Nemeth book is very good:

http://www.amazon.com/Linux-System-Administration-Handbook-E...

I've only read the 3rd edition, but it looks like this newer edition also includes Linux.

Well damn.

Though, it did feel inevitable after so long without news.

If you're not sure who she is, take a moment to read up [0][1].

0: http://en.wikipedia.org/wiki/Evi_Nemeth

1: http://www.amazon.com/dp/0131480057