Linux/Unix System Administration
This Website (http://www.bol.ucla.edu/~dmorgan1/linadmin/) will be used to communicate with you. Announcements, grade reports, and assignments will be posted here. The site can be viewed from an internet-connected browser anywhere. You are responsible for awareness of the information posted here.
Thank you - for your interest in linux and this course. I have enjoyed spending this quarter with you. (3/14)
Related linux/unix classes - that may interest you.
Advanced Linux/Unix: Networking - networking, emphasizing the linux
platform commands to "do" it
Schedule: the courses tend to be
offered every other quarter. There may be variations but this is the
general expectation. If you are
interested please "stay tuned" to the class schedule as UCLA
Extension publishes it. Or if you email me I can let you know what we are
putting in the pipeline
Calendar - 2 more meetings including tonight: March 7 and March 14 (3/7)
Final - will be a take-home exam. It is multiple-choice. Submit your answers to all the questions following these preparation and submittal instructions (you will use scp/sftp to deposit your answer file in your "assignments" subdirectory on unexgate.dmorgan.us. Please name your file "final.txt". I will grade these using an automated script, so the format of the answer is critical to intelligibility, as is the case (lower) of the filename. -due on unexgate.dmorgan.us by end-of-day Wednesday, 3/21 (3/7)
What must be known? in order to set
the system clock based on the hardware clock?
Homework - follow readings on course outline as we cover the topics-- 5 (task scheduling), 6 (time, clocks). (2/21)
RSA algorithm's math - is interesting to learn. It's what makes public/private key pairs work. We may have time to go over related slides. (2/14)
An analogy for passphrases on private keys. (2/8)
A convenient command - that automates the ssh key placement process. We did step-by-individual-step key placement in the lab exercise. There is a command to do the same thing more automatically. We did not use that command in the interest, tutorially, of learning what's actually going on. The command is ssh-copy-id. If the exercise were to have taken advantage of it, you could have done:
ssh-copy-id -i ~/.ssh/id_rsa.pub firstname.lastname@example.org
Provided you could authenticate as unexgate's student01(i.e., knew its password), your local public key would find its way into remote student01's authorized_keys file, as needed. (2/6)
If you want to learn a lot of linux in a little time - I recommend the SCaLE 16x (Southern California Linux Expo) held Friday - Sunday March 8-11, 2018. It's intense, inexpensive, local. (2/3)
Working account assignments on unexgate:
These are ancillary accounts for you to use in exercises about ssh and backing up. (1/31)
Choosing which hash algorithm to use for scrambling passwords - that's recorded in the file /etc/pam.d/system-auth and can be set using the utility authconfig. (1/31)
yubikey device - comes from yubico. Google established a business relationship with yubico last fall for implementing 2-factor authentication using yubikeys. It uses a particular yubico product called Fido U2F security key. The FIDO ("fast identity online") alliance is an industry group promoting 2-factor authentication. (1/31)
Is there a better way to hash passwords?? (1/17)
Homework - follow readings on course outline as we cover the topics-- 2 (user admin), 3 (backup), 4 (logging). (1/17)
Hashing the text string "hash me please" in linux with an individual command for each hashing algorithm, and in Windows with HashCalc:
Homework - see course outline, topic 1. Do the reading shown there. (1/10)
useradd command - changes the inode of /etc/passwd routinely. It has nothing to do with whether there are any hardlinks or not. "changing the inode" is the wrong way to phrase it, I think. useradd probably makes a copy of the file (which thus has a different inode). It applies its changes to the copy. When ready, it renames the copy to "/etc/passwd" which destroys the original. Something like:
cp /etc/passwd temppass
The rationale for doing it this way would be to minimize
the chance of leaving behind a damaged file if anything interrupted the
process before it could be completed.
Course outline - with approximate weekly topic coverage corresponded to related readings, homework assignments, and in-class slides I will use.
Optional Linux 101 exercise - for those who want a quick hands-on with a dozen top commands. If you lack experience using linux/unix, here is an optional "Linux commands" exercise you can perform on a remote linux server where I've created an account for you. Designed originally for other classes as a homework assignment, for you it's a strictly optional offering. Do it if you think it would be useful. (If you have any doubt whether you would be able to use cat, echo, mv, or ls if asked, I'd say it would probably be useful.)
My 3 favorite linux books (see the
syllabus), respective strengths:
Requests - please don't change the passwords on the "root" or "student" accounts of the classroom workstations. At the end of each class please power the machines down either via the GUI menu system or the "poweroff" command.
Handout - explaining use of class computers.
Welcome - you may view (almost all of) the presentations shown in class via links to them as pdf files, bottom of left column. See also the brief class syllabus, at the link entitled "Syllabus," upper left. The textbook is identified there.
A Remote Unix system will be available for your use.
Using ssh (secure shell). ssh is an important tool you will use for interacting with remote computers. For that you will need an ssh client. There are a number of ssh client alternatives.
Running linux at home.
hath God wrought?"
Watson come here, I want to see you."
rotating log files
monitoring log files
yum and rpm