This semester, I'm teaching my class on System Administration / Internet Operations once again.
The syllabus and all course materials are available here:
https://stevens.netmeister.org/615/
All videos for the lectures and exercises are public and available for free on YouTube:
https://www.youtube.com/c/cs615asa/videos
If you want to follow along, I'll be posting lecture videos and related links in this thread throughout the semester.
System Administration, Week 1: Introduction
In this video, we cover a number of administrative issues relating to our course: we discuss why and how System Administration is covered in an academic Computer Science curriculum and outline the course syllabus.
System Administration, Week 1: The Job of a System Administrator
In this video, we try to capture the job of a System Administrator. We show what things SysAdmins may encounter in their day to day routine, ranging from blade servers and routers to cable ties and power tools and everything in between. As we try to define the job, we find out it's not quite that easy...
It's duct tape and WD40 all the way down.
System Administration, Week 1: Core Principles
In this video, we present a few core principles that will guide us throughout the semester: Scalability, Security, and Simplicity. We'll also get to know a few basic "laws", well known by any System Administrator. If you're wondering what all this has to do with Legos, please tune in...
System Administration, Week 1: UNIX History
We're borrowing this video from our "Advanced Programming in the UNIX Environment" class to give a brief summary of the history of the UNIX family of operating systems.
System Administration, Week 1: Warming up to EC2
In this short video, we prepare for our first homework assignment and demonstrate how to launch a #NetBSD instance in AWS EC2.
https://www.youtube.com/watch?v=cA_pgRH0IDw
Note: the AMI in the video is outdated; I have up to date images listed here:
https://stevens.netmeister.org/615/netbsd-amis.html
Or you can create your own:
https://www.netmeister.org/blog/creating-netbsd-ec2-amis.html
System Administration, Week 1: AWS Aliases
System Administrators are notoriously lazy, and AWS commands a notoriously lengthy to type. In this video, we demonstrate the use of shell aliases and functions to save ourselves some typing whenever we run AWS EC2 commands.
The aliases and shell functions we use are available here:
https://github.com/jschauma/cloud-functions/blob/main/awsfuncs
System Administration, Week 1: Warmup Exercise 1 - No Space Left On Device
In this video, we try to find out what happens when we run out of disk space as well as how the system behaves when use up all inodes. This is intended as a warmup exercise for our week 2 topic, introducing the concept of disk storage and filesystem behavior.
System Administration, Week 2: Storage Models and Disks
In this video, we'll introduce the larger topic of filesystems and storage. In particular, we'll discuss the conceptual storage models, such as Direct Attached Storage (DAS), Network Attached Storage (NAS), Storage Area Networks (SANs), and Cloud Storage.
System Administration, Week 2: Devices and Interfaces
This segment discusses common storage device interfaces, including SCSI, ATA, SSD, Fibre Channel, and hinting at storage configurations like JBOD and RAID, which we'll get back to in the next video. At this point, it feels a bit dated, and I may skip it going forward and perhaps expand more on enterprise storage, but then again, it's only 10 minutes of your time.
System Administration, Week 2: Storage Virtualization
In this video, we cover the concept of storage virtualization -- combining individual disks into larger storage pools and utilizing resources from such a pool. This includes a discussion of RAID and some of the different supported levels as well as Logical Volume Management (LVM). We further illustrate some of these properties by example of ZFS.
System Administration, Week 2: Physical Disk Structure
We'll take a quick look at what a hard disk drive actually looks like. This helps us understand addressing schemes such as CHS and LBA, what physical aspects affect hard disk performance, as well as partitioning requirements. While a lot of this is tied to old magentic-spinning-platters drives, it explains a lot of assumptions partitions and file systems make even if using SSDs.
System Administration, Week 2: Partitions
In this video, we talk about how to divide a single disk -- physical or virtual -- and how the partitions relate to the physical structure of the disk. We show examples partitioning disks on NetBSD, OmniOS, and Linux using the disklabel, fdisk, and format tools.
System Administration, Week 2: Moving EC2 Volumes
We've talked about EC2 Elastic Block Storage volumes, and how we can treat them as if they were hard drives plugged into an instance. In this video, we run through one of our recommended exercises for Week 2 and show how to move an EBS volume across instances and operating systems from a NetBSD EC2 instance to one running Ubuntu Linux.
System Administration, Week 3: The Boot Process & the MBR
In this video, we discuss the boot process on a high level as well as take a fairly detailed look at the MBR. We'll create a suitable NetBSD BIOS partition by hand, utilizing the dd(1) command because using fdisk(8) would be just too easy. In the process, we learn a fair bit about the structure of the boot sector.
System Administration: Week 3: File systems
In this video, we pretend to be a file system, trying to store all our cat photos in a reasonable manner on a raw disk. By manually writing data and metadata, we begin to understand what a file system has to do. We also show how the tar(1) utility creates output that very much resembles a filesystem format.
System Administration: Week 3: Files go hier(7)
In this video, we're wrapping up our discussion of filesystems and partitions with a look at file types and partitions and filesystems mounted by default on #NetBSD, #FreeBSD, #OmniOS, and Fedora Linux. We close with a look at the filesystem hierarchy as defined in the hier(7) manual page.
System Administration: Week 3: Resizing a file system
In these two videos, we show how to resize an existing filesystem. First on #NetBSD using the resize_ffs(8) tool, where we first increase the size of a 512MB partition to 1GB, then shrink it down to 256MB. Next we repeat the same exercise on #Debian Linux, using the resize2fs(8) tool.
System Administration: Week 4: Types of Software
With this video, we begin our Week 04 topic of "software": what types of software there are, how they fit together, how to install software, and how to manage dependencies. We try to draw a terrible analogy to - what else - cars, and quickly realize that the distinctions between firmware, operating system, system software, add-on software are difficult to make.
System Administration: Week 4: OS Installation
In this video, we perform a step-by-step manual installation of #NetBSD onto a virtual machine to illustrate the details of the process, including partitioning, boot loader installation, OS set extraction etc.
We also discuss planning of the OS installation by looking at data classification into shareable/non-shareable and static/variable data and think about how to scale this process.
System Administration: Week 4: Package Management
In this video, we continue our discussion of the difference and relationship between the operating system and so-called "add-on software". We conclude that in order to install and maintain all such software, we want to use a package manager, and illustrate common features by example of the 'dpkg', 'rpm', and #NetBSD's #pkgsrc tools.
System Administration: Week 4: Package Management Pitfalls
In this video, we discuss some of the problems with package managers, native language packaging solutions, and the implications of their use on dependency resolution, package integrity, and trust. We revisit "left-pad" and "dependency confusion" to illustrate some of these problems.
ah, out of inodes... was sysadmin for a software testing team. one of them was doing auto generation of test cases in prolog, where the entire tree of tests to run was mapped to directories and files in the unix filesystem. problem was that the number of possible tests to run was an order of magnitude higher than the combination of all inodes on all file systems on the computer. he'd run his prolog, trash his machine, then get us to "fix my workstation". good times.
Jan Schaumann
Jens Link
Kris
Jan Lehnardt 
wfk
Paul_IPv6
Oumuamua