Week 3 in the Google IT Support Professional Certification course is all about the wonderful world of operating systems. Apparently, according to the introductory video, the operating system is really important. Definitely writing that down!
The OS is software that manages the system’s resources and allows the user to interact with the computer. The “kernel” is the part of the OS doing all the system management, and the “user space” is the part that you interact with, whether it is a command line or a GUI.
The three most common operating systems are Windows, Mac, and Linux. The presenter points out that Chrome OS is gaining in popularity due to the rise of Chromebooks, which could be true, but that it is running on the Linux kernel anyway, so it isn’t really a substantive claim. What is more noteworthy is that mobile is growing so fast… hey, does anyone know what happened to Windows Phone? Anybody???
The kernel handles these critical functions:
- File management: the file system is the system the OS uses to manage files. In Windows the file system is known as NTFS.* For MacOS the default file system is HFS+. Different Linux distributions use different file systems, but EXT4 is common and is compatible with an older file system called EXT. Data is stored in what are known as data blocks, which means that a file can be stored in different physical locations across a disk, and can be accessed faster than if it was stored sequentially in one big piece. Another important part of file management is the metadata, which is the information about a file – file owner, permissions, file type (which can be discerned by the extension), date created, date modified, file size, etc.
- Process management: A process is some part of a program that is executing. The kernel allocates a “time slice” for the CPU to execute a process, since the CPU has finite processing power. The kernel creates, manages, schedules, and terminates processes.
- Memory management: Processes need space in memory so that the CPU can execute them. A system will use what is called “virtual memory,” a combination of hard drive space and RAM, to increase the effective size and speed of RAM. A process is divided up into different “pages” that can be moved and allocated to virtual memory. The part of a hard drive used for virtual memory is known as “swap space.”
- I/O management: The kernel also manages all the input and output from any I/O devices such as cameras, mics, keyboards, etc., by loading drivers and allowing the use of these devices. A slow machine is usually caused by some hardware resource deficiency, which is related to I/O somewhere in the system.
The “User Space” is everything outside the kernel, all the stuff you interact with. This is either done through a Graphical User Interface (GUI) or through a “shell,” such as the Command Line Interface, or CLI shell. In Linux the most common shell is BASH (Born Again Shell) and in Windows there is something called PowerShell.
Logs: Operating systems keep a record of events that you can access to diagnose problems. Finally, some damned accountability!
The Boot Process: Power On, BIOS/UEFI initializes hardware, POST (Power-On Self Test), boot device is selected according to BIOS/UEFI configuration, when a bootloader is found on a boot device, it will begin to execute loading the OS. Once the OS is loaded the kernel will load, starting up drivers, I/O functionality and the user space.
How to decide which operating system to install? This will be determined by your hardware, application needs, or those of your organization. Obviously you need an OS that will run on your CPU, i.e., a 32 bit OS running on your 32 bit CPU. At this point we are directed to read a 4 year old article about choosing an OS. Okay, well, fine.
Then follows a brief intro to virtual machines and how the student is going to connect to VM’s used in the labs throughout the course. The presenter was very clear to point out that she had “already read” the terms of service, so she could just click “agree” without scrolling through. Sure.
Then comes a walk-through of installing Windows 10 on a computer. Whooo-boy it doesn’t get much more exciting than…
Next we are creating a file in Windows. You can right-click, on the desktop, select New, and here we select, oh, let’s go crazy and select Text Document. Yowza!
Next, we are installing the popular Linux distribution called Ubuntu, using “bootable” install media. This “bootable” part is very important, or else your media won’t be. Use a tool like etcher.io to create bootable media. Once Ubuntu is installed, we get a brief tour of system settings and then open up Terminal to create a file. Terminal will show you something like this when you open:
This means that a user named “user” is at a computer named “hostname_location” and is currently in the directory called Desktop. Or, more simply, we are working in the desktop of the computer. To create a new file, type the following shell command command:
user@hostname_location:~/Desktop$ touch my_new_file
The touch command creates a new file on the desktop. I am already slightly familiar with Linux commands but it has been awhile, and I never learned that many. Very excited to learn more, as this is what real “computing” looks like–perhaps I’ve seen too many 80’s movies, but I am glad to know that actual IT people get use this stuff.
Installing Mac OS X. This video starts with the presenter saying that since Macs come with the OS installed, we are skipping over that process. Okay, then… Instead, there is a brief overview of some of the components of Mac OS. Clicking on the “Apple” menu and selecting System Preferences is where all the system settings are located. Finder is the file management tools used in the Mac OS. I know from work that the installation on a Mac is pretty easy if the machine has an internet connection. Not sure about using installation media, and at this point, most of the newer MacBooks don’t have much in the way of ports, so you’d be playing the storage/dongle game. Which is not as much fun as it sounds!
Then it’s time for 3 question quiz, and finally a video about how to open the VM platform to do the graded lab assignment. The intro page says that to do this Linux lab we should do the exact same thing as the Windows lab we just completed, but I have not seen any Windows lab yet. Not quite time for angry tweets but, hey, it’s not like Google should be good at organizing information, or anything… jeez!
I “already read” the terms of service so I just blindly click accept… Then there’s a screen saying “Create a Folder With Linux” even though we have only learned how to create a file… I think the command is mkdir but I guess we will see…
eduit36450_student@linux-instance:~$ mkdir my_new_folder eduit36450_student@linux-instance:~$ cd my_new_folder eduit36450_student@linux-instance:~/my_new_folder$ touch my_new_file eduit36450_student@linux-instance:~/my_new_folder$
As far as I can tell it worked. I know that I made a new folder, because “cd” changed the directory to “my_new_folder.” I closed out the tab like the directions said and the cloud platform said that the lab was complete. I also read further down and see that it actually gives you the command for making a folder. I guess all the labs are going to have step by step instructions? Possibly?
Back on the Coursera page, however, I clicked “Next” to go to the next lesson and it automatically started Week 4. I clicked back to Week 3 and saw that my Linux Folder lab was incomplete and that there actually WAS a Windows lab. The completion of which has momentarily been derailed as I am unable to RDP into my Windows VM without installing Chrome, something I had somehow managed to avoid doing this whole time in this course. I also have a new used computer with a brand new installation of Windows 10 that I wanted to avoid filling up with software I never use. Anyway, Chrome it is, then. That is downloading now, and is taking its sweet time about it.
So once Chrome is installed you have to add an RDP extension to it. Once that is installed you are supposed to be able to log into your Windows VM. This next part is important: instead of using the username they provide in your VM credentials, you have to change it to “student” for some reason. This ate up some time… But, once I was in, I was able to right click on my desktop to create a folder. Wow.
I checked back to the Week 3 outline and still don’t seem to have credit for the two labs.° Going to have to check back on those before 2/11 but for right now it looks like I am moving along to Week 4 – Networking!
*There is another Windows file system in development called ReFS, or Resilient File System.
°After about twenty minutes I checked back and found that the lab work was credited in my Coursera profile.
AFFILIATED OPERATING SYSTEM: WINDOWS 10 Apple 13" MacBook Pro, Retina Display, 2.3GHz Intel Core i5 Dual Core, 8GB RAM, 128GB SSD