Introduction to RHCSA

0:00<v ->Hey friends, and welcome</v>

0:01to the Red Hat Certified System Administrator Course

0:05here on CBT Nuggets.

0:07So to get us going, the first thing that I want to do

0:10is just to talk to you about

0:12what you can expect to see on the exam.

0:14Basically, what are the exam objectives?

0:17What do we have to know?

0:18What are we going to learn in this course?

0:20And then what I want to do is to talk to you

0:22a little bit about the actual format of the exam.

0:25So with that said, let's just dive in

0:27and find out what this exam is all about.

0:30So the very first thing to know about the RHCSA exam

0:34is that this is a performance based examination.

0:38Quite simply, this is not a written exam,

0:40it's not going to be a multiple choice exam,

0:42anything like that.

0:43Instead, it's going to be you

0:45with a Red Hat Enterprise Linux operating system,

0:48completing a whole series of tasks.

0:50Now, one thing to note

0:51is that the skills tested in this exam

0:54are pretty much a foundation for system administration.

0:57So this would be considered

0:58more of an entry level examination.

1:01And as you can see here, by passing this exam,

1:03you become a Red Hat Certified System Administrator.

1:06Now let's just talk briefly

1:07about what you can expect to see within this examination.

1:11So the exam objectives specify we have to understand

1:14and use essential tools, that sounds pretty generic.

1:16What does that actually include?

1:18Well, it sets here things like creating

1:19and editing text files, creating hard and soft links,

1:23accessing systems via SSH, that type of thing.

1:26Now, one thing to say, if you don't actually know

1:29what any of this stuff is, do not worry,

1:31we are going to be covering all of this

1:32within this particular course.

1:35Similarly, if I scroll on down, we're going to learn

1:37how to create simple shell scripts,

1:39understand how operating systems actually work.

1:42So we'll talk about how we can boot,

1:43reboot, shut down systems, identify intensive processes

1:47and kill processes, that type of thing.

1:49And scrolling on down, we can see

1:51more and more of these objectives.

1:52Configure local storage, create and configure file systems,

1:55deploy, configure and maintain systems,

1:57as well as understanding basic networking concepts.

2:01So we'll also talk about what IPv4 is IPv6,

2:04how we can configure hostname resolution,

2:06what that actually means, what is its purpose,

2:08as well as discussing how we can create and manage

2:11users and groups in our system.

2:13And the last two things that we have to understand

2:16is how we can actually manage security on our system.

2:18We know in modern systems

2:20security is a very, very important subject.

2:23So it is no surprise here

2:24that we are going to have to understand

2:26how we can manage our system in a secure fashion.

2:29And the last objective is a more modern technology,

2:32and this is all around the concept of containerization.

2:35Once again, if you have no experience with containers,

2:38do not worry about it,

2:39we will definitely get to it within this course.

2:42Now, one last thing I just want to point out

2:44is that the actual format of the examination

2:46is that, like I say, it's going to be

2:47a hands-on practical exam

2:49where you're going to be asked to perform

2:51particular real world tasks.

2:53And because of this, the way this course

2:55is going to be formatted is we're really going to have

2:58a strong emphasis on validating what it is you know

3:01by asking you to perform particular real world tasks

3:04so that you're really getting the preparation needed

3:06for taking the real exam.

3:08Now, very, very important.

3:09It also specifies that in the examination

3:12you're not going to have internet access.

3:14So you can't go and use the big Google machine

3:16to search for answers or to help you troubleshoot problems,

3:19nor will you be able to bring in any type of documentation.

3:23So no hard copy or electronic documentation

3:26is allowed at all.

3:27So no notes, no documents, that type of thing.

3:29But as you're going to learn within this course,

3:31there are actually things within the operating system itself

3:35that you can use within the examination

3:37to help you out when you get stuck.

3:39Okie dokes, so that is what you can expect

3:41from the examination

3:42as well as the content within this course.

3:45The next thing we're going to be talking about

3:46is how we can set up our lab environment

3:48to begin testing our skills.

3:51And well, that's what we're talking about

3:52in the very next video.

0:00Alright friends so what we're going to do in this particular video is we're

0:02going to go and get

0:03some virtualization software so that we can well so we can virtualize our

0:08operating system.

0:09Now just to be clear here there are different solutions that you can use for

0:12this virtualization.

0:14For example one tool you can use is something known as virtual box. Another

0:18option is something

0:19known as UTM and there are a few others but the one that I'm going to be using

0:23is this one right

0:24here VMware. Now there isn't anything special about VMware you can choose any

0:28which one you so

0:29wish depending on your platform. VMware just happens to be my own personal

0:33platform so this

0:34is the one I'm going to walk through the basic installation of. So once we have

0:37that up and running

0:38then we'll go and get the operating system that we're going to be using for Ans

0:42ible okay so let's

0:43go and download VMware first then. So let's go to a browser here and all I'm

0:48going to do is set for

0:50VMware download okay so it should take you to this website right here okay.

0:54Alright so just to be

0:55clear here VMware has actually been bought by Broadcom and since this has

0:59happened well some

1:00people who complain that downloading VMware can be a little bit cumbersome and

1:04I wouldn't

1:04necessarily disagree with that but nevertheless what I'm going to do is I'm

1:08going to walk you

1:09through how you can effectively still get VMware okay or at least this will be

1:13the process when

1:14I'm recording I can't guarantee that in a year's time that it's going to be

1:17different but fingers

1:18crossed that it's going to be okay. Alright so what I'm going to do is go to

1:22the download

1:23now button right here so let's just click here as so and what it's going to do

1:27it's going to take

1:27me to the Broadcom website so this is the redirection I was talking about so

1:31just give this a moment

1:32and what we can see here is where we have a login page okay so let's just zoom

1:36in a little touch.

1:37Now first thing is first if you have a Broadcom account you can just go and log

1:42in if you do not

1:44have an account we're going to have to go and create one so if you just go and

1:47search for create

1:48Broadcom account what we can do is just go to this link here to register and

1:52pretty much

1:53all we're going to do here is to walk through a simple registration process so

1:56pretty much

1:56typing your email address and we're going to have to enter in the capture form

2:00right here

2:00and all I've done now is they've sent me a verification email. Alright so all I

2:04've done is

2:04went to my email account I'm going to paste in the numbers that they sent me

2:07here okay so let's

2:08just go and verify and what I'm going to have to do now is to fill in some

2:11registration details

2:12sort of type in my name select my country you can go and select a job title

2:17then type in a password

2:18and just accept the conditions here and then we can create the account. Alright

2:22so we have

2:22successfully registered and for now what I'll do is just say I'll do it later

2:25so in this stage

2:26here if we go back here let me type in my email account now it says here that

2:31permission has been

2:32denied this is part of the annoying stage since the Broadcom acquisition so

2:37what we're going to have

2:38to do is we're going to have to unlock the account so you'll notice here that

2:41upon first login

2:42you'll see a message saying your account is locked to unlock the account follow

2:46all of this stuff

2:47you're documenting okay so let's click this here and what we can actually see

2:50here is the resolution

2:51that we have to go through okay we're just doing a lot of bits so you're going

2:54to have to go to the

2:55support portal and then click login in the upper right corner so let's go up

2:59here login type in the

3:00password alrighty oh so after all that nonsense it appears that we have logged

3:05in okay so what I'm

3:06going to do now is go to my downloads and what we're going to see here is no

3:09data is found but we

3:10have this option here for free software downloads available here okay so what I

3:14'm going to do here

3:15is choose this here click this now at this stage here I should be able to go

3:19and search for vm where

3:21okay so let's just show results now here is the software right here okay so

3:25depending on what you

3:26happen to be using the i.e the computer you have the software that you want is

3:30going to be a little

3:31bit different because it happened to be in a Mac I want to download vmware

3:34fusion which is their

3:35Mac book implementation okay whereas if you happen to have a Windows machine or

3:40a Linux machine you

3:41can choose vmware workstation pro okay so depending on which one you have

3:44choose the correct one

3:46okay so I'm going to go to vmware fusion now this stage here the version as I

3:49record this is

3:50going to be vmware fusion 13 let's click this right here and I'll just choose

3:54the latest release

3:55okay so let's click this if I try to download this again we're going to have a

3:58little bit of an issue

3:59look at this can't do it can't do what's going on well first thing we're going

4:02to have to do is

4:03to agree to the terms and conditions now what you'll notice is is if you try to

4:08click this

4:08seems like you can't click it you have to make sure you click this link right

4:12here terms and

4:13conditions now you you should redraw this okay so we're going to go and redraw

4:17this of course and

4:18once you've done that now that you've clicked this now you can actually tick

4:21this box but make

4:22sure you actually click this link first okay now at this stage here we can go

4:26and choose to download

4:28but again you're going to see something else it's leaning as required more

4:31hoops to jump through so

4:32fun fun let's just download this and it says you're prior to downloading this

4:35additional verification

4:37is required to let's proceed okay so what i'm going to have to do here is to

4:40type in information

4:41related to who i am pretty much my name my address my postcode all of that

4:45stuff and then

4:46once i've done that i'm going to choose submit so i'm going to go through this

4:49i'll blossom it out

4:50and then once i'm done i will go and submit this okay all right so with that

4:54now done what i will

4:55do is choose submit okay so here we go now what i should be able to do is to go

4:59and download this

5:00or click here the download should begin let's just save this as so and hey we

5:05're now beginning to get

5:06VMware downloaded okay so i know it's quite a bit of well it's quite difficult

5:11to be honest but

5:12hopefully at home you weren't able to get this up and running assuming that

5:15they haven't changed

5:16anything of course and they'll now have access to this really good virtual

5:20ization software all right

5:21so now the downloads should be complete let's go up here and let me just click

5:25this i'm going to do

5:26to double click to install fusion and i'll choose to open it type in my

5:29password to confirm so now

5:31we have VMware up and running what we're going to do now is to get a copy of

5:35Retat Enterprise Linux

0:00<v Instructor>So let's now walk through the installation</v>

0:02of Red Hat Enterprise Linux on our VMware player.

0:06So I will go up to file

0:07and create a new file,

0:09now, right now here it says select the installation method.

0:12What I'm going to do is I'm going to install a disc

0:14from an image.

0:15I will just click continue here.

0:16Now once again, if your interface looks a little bit

0:19different from mine, don't worry about it too much.

0:22Since I have already used Red Hat Enterprise Linnux on this

0:25machine before I can already see it here.

0:27But if I don't, I will choose use another disk or disk image

0:30and from within the download I will just select in my case

0:33here, the Arch 64.

0:35Of course, if you downloaded the x86 version,

0:37you would choose that, whatever it may be.

0:39So now I have this image right here, my Arch 64

0:42and I will choose continue.

0:43So right now it gives me a summary of my automatic settings.

0:48By default, I'm getting two gig of ram.

0:50This is the memory and I've also got 20 gig

0:54of hard disk space.

0:56And these really are the minimum

0:58requirements that you're going to have to need.

1:00Two gig ram, 20 gig storage.

1:02Now if you happen to have more space that you can spare

1:05and more memory available to you, then

1:07by all means you can extend these configurations.

1:09But if you don't, well these settings should be enough.

1:13Now if you happen to be on a Windows machine,

1:15the output here will look a little bit different,

1:17but in my case here on a Mac,

1:18you can just choose customized settings

1:20or just give us a name of Relto, save here.

1:24And in the Mac I can go into processes and memory

1:26and I can crank up my memory settings.

1:28Let's give it maybe say four gig or so.

1:30Go to show all, go into the hard desk

1:33and if I want to create more space, say for example like

1:3640 gig, then I can just do so via the slider

1:38and choose apply.

1:39Once again, the Windows interface will be slightly

1:42different, but the core principles remain the same.

1:44You can easily modify your RAM that you want to allocate

1:47to your machine as well as the available disc space.

1:49So if I just choose apply, what I'm now going to do is

1:52to press this big button to start up my machine.

1:54So let's do that.

1:55So right now we have the option

1:56to test this media.

1:58I'm going to recommend we don't do that

1:59and arrow up to the top just

2:01to simply install Red Hat Enterprise Linux.

2:04So if I just hit return here and just give this a moment.

2:07Great, so we've came to this first page

2:10and this page is going to allow me to specify the language

2:12that I want to use during the installation process.

2:15Now I am speaking English in the United Kingdom.

2:18So that is what I'm going to select.

2:20If you so wish, you can just toggle through all

2:23of these options and choose the one that best suits you.

2:25So English UK for me, and then I will click continue.

2:28Now here is the thing, we have some options

2:30in terms of localization.

2:31We can specify the actual keyboard here.

2:33Once again, I am English uk.

2:35If you want to change this, you can press the plus sign

2:39and specify a different option.

2:40Perhaps you're in the USA, for example,

2:42but right now this is all good for me.

2:44So I will just choose done.

2:45The next thing I will do is choose my time and dates.

2:48Once again, I am in the UK,

2:50so I will just make sure I'm choosing the London region

2:53or rather the European region with the city of London.

2:56If you want to choose something else,

2:57and of course you can go to the dropdown,

2:59choose wherever you are, whether it's Africa, Asia,

3:02Australia, whatever it may be,

3:03and then you can select your own city.

3:05Right now, like I say, London is good for me,

3:07so I will just choose done.

3:08The next thing I'm going to choose

3:10is the installation destination.

3:13So right now what I'm going to do is I'm going to make sure

3:15that my desk here is ticked.

3:17Notice the size in my case is 40 gig

3:20because I extended the size from 20 to 40.

3:22If you left at the default, you can expect to see 20.

3:25My storage configuration, I'm going to leave at automatic

3:29and I'm not going to bother worrying about encryption.

3:31So right now that is all good, so I will click done.

3:33The next thing I'm going to do

3:35is I'm going to select the network and host name.

3:39All I'm going to make sure is

3:40that this part here is toggled on as so,

3:42and it's connected right now we can see I'm getting

3:45an IP address.

3:46So with that I will now say done.

3:48My software selection, all I'm going to specify

3:51that is that I want the server

3:52with the graphical user interface,

3:54this should be the default.

3:55So if that is the case, just leave it so.

3:57And I'm not going to worry about any

3:59of these other particular utilities, right just now.

4:01So with that, let's just choose done.

4:03The root password, what I will do here

4:05is I will create a root password.

4:07This is going to act as the administrator password.

4:09So I'll type in a password here and I will just confirm it

4:12and I'm not going to tick locking the root account

4:15or allowing root SSH login with password.

4:17I will just say done.

4:19And now I will go to user creation.

4:20This is going to be the actual user of the user account

4:24that I will use when accessing the system.

4:26So right now I will just use my username of ipvzero

4:30and bad security.

4:31I will just give this the same password that I gave

4:34for the root accounts.

4:35Once again, this is something you should not do in a real

4:37production network,

4:38but because it's just a little lab environment

4:41and a virtual machine, then I'm being a little bit relaxed

4:43on security and I'm also going to specify

4:45that this user is an administrator.

4:48This means that I'll be able to use this account

4:50to actually act as the admin in particular circumstances.

4:54So with that said, let's now click done

4:57and we should be pretty much good to go.

4:59So let's now click begin installation.

5:01So if you just give this some time,

5:02depending on your system, it may take longer,

5:04it may take shorter, but in my case here,

5:06I'm going to grab a coffee, pause the video

5:09and I will see you when this is up and done.

5:10Okay, so now the installation is complete.

5:13I will just choose reboot the system

5:15and the reboot will begin.

5:16So here we are.

5:17I will just click on my username here

5:19and type in the password I created and bam, there we go.

5:22So if you so wish you can take the tour,

5:24but right now I'm just going to say no thanks.

5:27Now what it says here is that the system is not registered.

5:30You're going to have to register the system

5:32to actually receive software updates.

5:34We'll handle this in a moment.

5:35The first thing I want to do is I want to go up

5:38to activities here,

5:39and then I will go down to this option here, terminal.

5:43This is what we want to get.

5:44So let's click this here

5:45and I will just expand this a moment.

5:47So you'll notice that the text is super tiny.

5:49We're going to modify this.

5:51If you go to this option right here

5:53and get down to preferences,

5:55what I'm going to do is I'm going to go

5:56down to my profiles.

5:58Now the profile that I have is unnamed.

6:00So the first thing I'm going to do is I'm going to select

6:03custom font.

6:04So I'll just tick this and all I will do is go over here

6:07and I can change the size by pressing the plus arrow.

6:10So always make this nice and big for you.

6:12Right here I will choose select,

6:14I will disable the terminal bell.

6:16If you want to change the colors on the actual screen,

6:19then you can untick use the colors from the system theme,

6:22which you can see here changes things.

6:23If you want to choose, say for example, green on black,

6:26so you look like a hacker

6:28or you want to choose black on white, whatever it may be,

6:31you have a whole bunch of options.

6:32So at this point what I'm going to do

6:34is I'm going to register my system right here

6:37with Red Hat Enterprise Linux.

6:39So the command that I'm going to type

6:40is going to be subscription manager,

6:43and that is subscription-manager, by the way.

6:45And then I will just type register.

6:47If I enter here, it's going to ask me

6:49for my administrative password.

6:51So just type in that admin password.

6:53And now I'm going to have to specify what my username is.

6:57This is going to be my Red Hat login information.

7:00So I will just give my Red Hat email address right here.

7:03And now I will specify the password that is associated

7:06with that Red Hat account.

7:08And then I enter, just give it a moment

7:10to register on the system.

7:11It's going to check the status,

7:13and now it says that the system has been registered

7:15with a particular ID.

7:17Now the next thing I'm going to do

7:18is I'm going to say subscription-manager once again.

7:21And then I will say attach.

7:23If I hit enter, once again, I will give my root password

7:27and hit enter, give it a moment.

7:29And now we can see here the system has been registered

7:31and software updates have been enabled.

7:34Perfect, so if I just clear the screen

7:36and now I will go to my power button

7:38and I'm just going to choose Power Off.

7:40Okay, I will then choose again, power off, give it a moment,

7:44and now the machine has shut down.

7:46So if I go back to my actual VMware library.

7:49Here, I have my virtual machine right here.

7:51What I want to do is I want to save this configuration.

7:54Like I say, this is going to give us a snapshot.

7:57So if I ever happen to make a mistake,

7:59what I can do is just tell the machine to go back

8:02to this current state where everything has been set up.

8:05It's nice and clean, nice and lightweight.

8:07This will give us a nice safe rescue point.

8:10So if I just highlight that machine, I'm going to go

8:12to virtual machine here, go down to Snapshots,

8:14and I will just choose, take snapshot.

8:16And that means that if I go into this machine

8:18and look at the snapshots,

8:20we can actually see I have a snapshot saved

8:22at the current time right now.

8:24So now that we have our system up

8:25and running, what we want to do is to begin

8:28to understand some of the basics behind shells, terminal

8:32and the general syntax we use on the command line

8:34when interacting with Red Hat Enterprise Linux.

0:00<v ->So now that we have our system up and running,</v>

0:02let's now talk about shells and terminals.

0:05So let me just go up to activities here.

0:08Down the bottom right,

0:09as we can see, we can have a terminal.

0:11This is exactly what we want to talk about,

0:13so let's just click this.

0:14Okay, so the very first concept

0:16that I want to talk to you about

0:17is something known as a shell.

0:19What on Earth is this?

0:21Well, right now, as we know,

0:22we have this Red Hat Enterprise Linux installation

0:26and here we are as a user,

0:28as you can see, we're looking quite happy (chuckles)

0:30and I know what you're thinking,

0:31how amazing are my artistic skills,

0:34but realistically, that is about as good as I can do

0:37unfortunately.

0:38So here we are, here is our RHEL operating system,

0:41we want a way to interact with this operating system

0:44and this is exactly what a shell actually gives us.

0:47It gives us as the user a way to talk to the OS.

0:50Now with respect to Linux,

0:53there are many different types of shell environments.

0:56You can use something known as a Zsh shell,

0:59as well as a regular Bourne shell as it's known,

1:02but the shell that we are going to focus in on

1:05happens to be, well, an extension of the Bourne shell.

1:07It's known as the Bourne Again shell.

1:10I know what you're thinking.

1:11It's kind of like these Jason Bourne films

1:13whereby you have the first one

1:14and then you have the sequel.

1:16And quite often in movies,

1:17the sequel does not live up to the standards

1:20of the original,

1:21but that is not the case here.

1:22In the Bourne Again shell,

1:23the re-imagination of the older Bourne shell,

1:27it really is a much better shell to work with.

1:30Now in the case of Red Hat Enterprise Linux,

1:32the default shell happens to be the Bourne Again shell,

1:35which is more commonly known as a Bash shell,

1:39hence the name Bourne Again shell.

1:41So this one here, the default

1:43is the one that we are really going to be focused in on.

1:45Now, the good thing with Bash

1:47is that we get a lot of good features

1:49such as auto completion

1:50when we're typing out particular commands

1:53or specifying particular paths.

1:55As you're going to learn,

1:56this makes our lives much, much easier

1:58but we're also going to have to be aware

1:59that Bash is case sensitive,

2:02meaning that if you type a command

2:04and you happen to specify a capital letter

2:07where a capital letter should not be,

2:09then that command is not going to work.

2:10So just bear that in mind and be careful.

2:13So we have this shell right here,

2:16like I say, it's a way for us to talk to the system,

2:18but the way we're going to access the shell environment

2:21is via a terminal,

2:23which is exactly what I'm using right here.

2:25Now the cool thing is that with respect

2:27to these graphical installations,

2:30this little application time running right now

2:32is actually what is known as a virtual terminal,

2:35and one of the cool features

2:37about having this virtual terminal

2:39is that we can actually have access to multiple windows

2:42at the same time,

2:43having multiple different shelf sessions on the go.

2:45So check this right here.

2:46If I just type out a general command such as ls,

2:50here we can see the outputs.

2:51However, if I go and click this little plus icon right here,

2:55I also get a second tab,

2:57so we can click the left one

2:58to get back to the original environment,

3:01but then I can click back over

3:02and then type in a new command

3:04and do different tasks if I so wish.

3:06This is one of the big advantages

3:07of having this graphical environment

3:09and these virtual terminals

3:11to give us access to our shell environment.

3:14Now, what I first want to do is to show you a command

3:16known as the who command.

3:18Let's just type this out here, okay?

3:19So if I say who and hit Enter,

3:22basically what this command is showing me

3:24is who is logged in to the system.

3:26So on the very left hand side,

3:27we can see the actual username,

3:29which is my username right here,

3:31we can see this option for tty2.

3:34Now, very generally speaking,

3:35tty just tells us about the terminal

3:38that is in operation,

3:39right now we have tty2,

3:41but say, for example, I went into a text-based environment

3:44that did not have the graphical use interface

3:46and tried to log into the system once again,

3:49we could actually spawn up another terminal session.

3:51This could be, say for example, tty3,

3:54and like I say, this information will be reflected

3:56via the who command,

3:57the user that is logged in, their terminal session,

4:00as well as time and date information

4:02about when that session was started.

4:04Now say, for example,

4:05I wanted to change my virtual terminal,

4:08what I could do is use the command chvt

4:11and then give an associated number for that terminal.

4:14So if I just happen to say,

4:15let's go with chvt and call it tty4,

4:19one thing to note here is that if I try to run this command,

4:22we're actually going to get an error

4:24and that is because I'm going to have

4:25to have superuser privileges right here.

4:28Basically, this has to be performed by the administrator,

4:31and I will talk about superusers

4:33and elevated privileges in a lot more detail

4:35throughout this course but for now,

4:37the command that we can use

4:38to invoke that superuser privilege is the command sudo.

4:42This is a super well-known command

4:44and it's something you're going to see all over the place.

4:47So if I just say sudo chvt

4:50and then give that terminal number that I want to spawn,

4:53if I hit Enter,

4:54it's going to ask me for my password

4:55for superuser privileges,

4:57I will type that in and bam,

4:59it snap me into this text-based environment,

5:01no longer are we in this graphical environment.

5:04So if I just log in with my username ipvzero,

5:07type in my password once again,

5:09we can see the last login from my previous session

5:12was on tty2 at 17:11.

5:15If I now say who, we can indeed see

5:17that I now have a session ipvzero for tty4.

5:20And once again, if I want to change back,

5:22I can just say sudo chvt

5:24and go back to terminal number 2 again,

5:27type in my password for the superuser, hit Enter,

5:30and now we flash back into the current session once again.

5:33So now we understand the concept of shells and terminals

5:37but that doesn't really help us navigate the command line

5:40and work with these shells.

5:42How on Earth are we going to do that?

5:44Well, that's what we're gonna be talking about

5:45in the very next video.

0:00<v ->So, let's now look at a few commands that we can use</v>

0:03to help us navigate our bash shell.

0:05So, the first command I want to talk to you about

0:08is the man command,

0:09and what this command is going to do,

0:11it's going to allow us to access the manual pages

0:14for a whole host of other commands on the system.

0:17So really, really helpful.

0:19So, the syntax in order to utilize this command

0:21is to specify the command "man"

0:23and then target the particular page that you want.

0:27Let me show you what I mean.

0:28So, take for example the ls command, okay?

0:31If I want to see more details

0:33around this particular command,

0:34I can just say man ls, and check this out.

0:37At the very top, we see the name, which is in bold text,

0:41and then we see the command

0:42followed by a very short little description.

0:45Now, the synopsis here actually tells us

0:48how we can utilize this particular command.

0:51So, what we have here is the concept of an option

0:54that we can give to our command,

0:55as well as what we're looking at here is an argument.

0:58Now, if we go to the description section here,

1:01we get a short little description

1:03about what this particular utility is going to do,

1:05similar to what we see here,

1:07but we get a little bit more detail,

1:09and now we can see all of these switches

1:11or options if you prefer.

1:13Now, notice the syntax.

1:14We tend to have a hyphen followed by a particular option.

1:17In this case here, -a.

1:20But adjacent to it, we can also see we have this --all.

1:24Pretty much what this is telling us

1:25is that we can get the same effect in either way.

1:28We can say -a or we can also say --all,

1:32and that effect is going to be,

1:33we are not going to ignore entries that start with a dot.

1:36Basically, directories and files that begin with a dot

1:39are hidden directories,

1:41so these are going to show those hidden directories

1:43as well as the regular listing within.

1:46So, these are all of the options we can use.

1:48We can do -a, we can do -A.

1:50Remember, what did we say about bash?

1:52Bash is case sensitive.

1:54So, if you change the case,

1:56you can get a different effect entirely.

1:58Once again, we have other options like --author, -b,

2:01so on and so forth.

2:02Now, with respect to this part here, the arguments,

2:06this would be the information

2:07that you would supply to the command.

2:09Let me show you what I mean.

2:11So, if I want to exit out of the man page,

2:13I can press the letter Q to quit, and now I'm back.

2:16As we can see, I can run the ls command

2:19and that returns the directory listing.

2:21However, if I want to add an option or a switch,

2:24I can do one of those,

2:25say for example, -a, like so, and hit Enter,

2:28and now we're seeing these hidden directories

2:31such as .mozilla or .local, that type of thing.

2:34And if I want to target a particular directory,

2:38I could feed that in as an argument to this command.

2:40So, I could say ls

2:41and then maybe target the pictures directory.

2:44If I enter, we get a listing,

2:46but as it transpires, nothing is inside of that directory.

2:49But if I tried another directory such as ls

2:52and tried the /var directory and hit Enter,

2:55as we can see, we can feed in the var argument

2:58to the ls command.

3:00And if for whatever reason

3:01we wanted to add an option to modify the behavior,

3:03we could do -a,

3:05and now we can also see some hidden file.

3:08So, as we can see here, just by utilizing the man page

3:11and targeting a particular command,

3:13we can see all of the options available for that command

3:16and how we can actually use that command,

3:18as well as having a description

3:20about what that command is able to do on the system.

3:23So once again, if we just go back into the man page for ls,

3:26if you use your down arrow,

3:28you can just scroll through all of this,

3:30but what happens is often

3:31these man pages are very, very verbose,

3:34so if you want to scroll through things a little bit faster,

3:37you can use the space bar

3:38to page through these pages one at a time.

3:41We also get information such as exit status.

3:44We'll talk about these later on within this course.

3:46We also get information

3:47relating to the author of this particular binary,

3:50as well as documentation information, say for example.

3:53So a whole bunch of info right here.

3:55Let's go up to the very top again.

3:57If I want to, perhaps,

3:58look for a particular piece of information

4:00within this documentation, this manual page,

4:03what I can do is press the / whilst I'm in the manual page.

4:07Look at the bottom left, I press /,

4:10and this is going to allow me to invoke a search.

4:12So, let's maybe say I want to find out

4:14how I can do a long listing.

4:16If I just type the letters L-O-N-G and hit Enter,

4:20automatically, it's going to begin searching right here

4:23to find that word within the document.

4:25Now, right now, the first hit is not actually telling me

4:28what I want to find,

4:29but if I press the letter N,

4:31that now snaps me to the next one that's found

4:34as well as the next.

4:35I can just keep pressing N

4:36and now we go to the next.

4:37Look at this at the very bottom here.

4:39<v ->l use a long listing format.</v>

4:42This sounds like what I actually want.

4:44So, if I press Q to quit,

4:46I can do ls and do -l to get a long listing,

4:49and now we've modified the behavior.

4:51Once again, if I want to target a particular directory,

4:55well, I could pass that directory in as an argument

4:57using the -l option to modify the behavior,

5:00and now look at this.

5:01So, really very important.

5:02Try to remember that when you happen to be stuck

5:05or you happen to forget, as we all do,

5:07a particular command, or how to use a particular command,

5:10one of the best ways to save you is to use the man page.

5:13Now again, if we do man ls, for example,

5:17I want to draw your attention to this part here.

5:19See, in this bracket we see the number one.

5:22Now, what is happening here is that the manual page

5:24happens to utilize different sections.

5:26Now, the range you can expect to see

5:28is section one all the way to section nine,

5:32and really for our purposes,

5:33the sections that we would be interested in

5:35would be sections one, five, and eight.

5:38Now, when we happen to see a man page

5:40designated as section one, these are for user commands.

5:45So, right now we can see ls, this is the manual page,

5:47and it's a user command.

5:49So I, as the user ipvzero,

5:51should be able to actually run this ls command.

5:54Now, section five relates to file formats.

5:57We'll talk about that a little bit later.

5:59But the next one I want to focus in on is section eight.

6:02Section eight relates to not user commands,

6:06but rather system commands.

6:08Basically, if it is denoted as section eight,

6:11this is really going to be for the root user.

6:14So, let me give you an example of what I mean here.

6:16Now, if I go into the man page for visudo,

6:19as we can see here, we get a very similar outlook.

6:22We get a name, tells us the name of the command,

6:24we have a short little summary,

6:26we get a full description

6:27telling us this edits the sudoers file in a safe fashion.

6:31Again, don't worry about what that is,

6:32we'll talk about that later.

6:34And we get a synopsis

6:35of how to actually use this particular command.

6:37So, if I press space bar,

6:38we can see all of the different options, so on and so forth,

6:41but the interesting part is if we go up to the very top,

6:44we actually see this as denoted in section eight.

6:46So, section eight is telling us

6:48this relating to system administration commands.

6:51So very often, although not always,

6:54when you happen to see this,

6:55you can generally expect to use the sudo command

6:58in conjunction with whatever command

7:00you happen to be reading about.

7:02So, let's test this out. Visudo is section eight.

7:04Let's press Q to quit.

7:06If I just run the command itself, visudo, and hit Enter,

7:09tells me permission denied.

7:10However, if I say sudo visudo and hit Enter,

7:14I will type in my admin passport and hit Enter,

7:17now suddenly I get access.

7:19Now, another good option aside from the man command

7:21is also to use the --help option.

7:24And notice I have the double hyphens right here.

7:27That is exactly how we're going to use this command.

7:29If I wanted to see the help page for the ls command,

7:32for example, I can say ls--help and hit Enter.

7:36If we scroll on up, very often as in this case here,

7:38we're going to see very similar information

7:40between the help page and the manual page

7:43for the same command,

7:44but very often, typically the help command

7:46tends to be a little bit shorter,

7:48a little bit more truncated,

7:49whereas the manual pages very often

7:51are really quite verbose and comprehensive.

7:54Now, another place that we can go

7:55to find information relating to our system

7:57is in the usr/share/doc directory.

8:01Now, what you find in here tends to be a bit more involved.

8:04It's not really where you're going to find information

8:06relating to particular commands,

8:07but rather for particular services on your system.

8:11So, say for example you want to find information

8:13relating to some logging service on your system.

8:17Very often you can find information and sample files

8:20within this particular directory,

8:22but generally speaking,

8:23the command that you will rely on most,

8:25and the command that I use

8:26almost every time I'm on a Linux system,

8:29is indeed that man command.

8:30So, definitely get used to using it.

8:32It really will help you.

0:00<v ->So now that we have an understanding</v>

0:01about Linux shells and terminals,

0:04as well as how we can retrieve information

0:06relating to particular commands,

0:08let's now talk about the file system hierarchy standard

0:11within Linux.

0:12So when it comes to the file system hierarchy standard

0:16within Linux,

0:17what we are talking about is the general way

0:20in which Linux file systems tend to be structured.

0:23Now, I use the word tend deliberately

0:25because this is not a mandatory implementation.

0:28That is every Linux distribution

0:30does not necessarily follow this particular convention,

0:34but it is indeed a strong convention.

0:36So whilst we might see slight variations

0:39across different distributions, the general structure,

0:42the general layouts is going to be very, very familiar

0:46independent of the distribution that you happen to be using.

0:49Once again though, with some small variations.

0:52Now let's just discuss how the file system

0:55is actually presented to you as the user.

0:57So here is the thing.

0:58Perhaps you are familiar with

1:00Windows based operating systems.

1:02Now suppose you went into a particular folder

1:05or directory that was known as the Downloads folder, okay?

1:09If you happen to access this on the command line,

1:12you could do this by specifying the full path.

1:14Now, the full path might look something like say the C Drive

1:18and then perhaps maybe a directory called users

1:22and a directory for say for example, John, which is my name.

1:25And then within John's directory

1:27there you can find the Downloads folder.

1:30So the thing to note is that this particular folder

1:33is explicitly tied in name

1:36to this particular physical disc, the C drive.

1:39Similarly, maybe you would go into another directory

1:42and perhaps that was part of the D drive,

1:44and then you would have another path entirely yet again.

1:47Let's maybe say it was a pictures folder, who knows?

1:50Now the thing to note here is that with respect to Linux,

1:53when we happen to be moving through directories

1:55on the actual terminal right here,

1:58the actual discs that you happen to be accessing

2:01under the hood are completely transparent to you.

2:04Now to be clear, there are ways in which we can find out

2:06this information and correlate this particular file path

2:10to a particular disc.

2:11But generally, just as you are regularly using

2:14the command line, this really is quite seamless.

2:17So what I mean is that feasibly you could go into

2:19the Downloads directory and be on one disc

2:22and then perhaps change into another directory,

2:24such as the pictures directory right here,

2:27and suddenly you're reading data

2:28from an entirely different disc.

2:30Now as it transpires in my case right here,

2:32both of these are all mounted at the same point.

2:35So we're not actually switching discs right just now,

2:38but I'm just letting you know that theoretically

2:40if say for example, this directory here

2:42happened to be mounted on a different disc entirely,

2:45then this output would still look the exact same.

2:48The change of location would not be noticeable to you

2:52as you go about your day-to-day business.

2:54Now with that said, let's talk about some of the directories

2:57that we can expect to see

2:58within this file system hierarchy standard.

3:00So the very first concept I want to discuss with you

3:02is the concept of roots.

3:04Now, what I drew here happened to be a forward slash.

3:08This is very, very important,

3:10because a forward slash on its own

3:12actually denotes the root of the entire file system.

3:16That is, this would be the parent directory

3:18under which everything else comes under.

3:20Now, as you're going to see,

3:21when we look at this file system,

3:23it's super important not to confuse the root directory

3:27with the actual root of the file system.

3:29Let me show you what I mean.

3:30So right now I'm going to change into my directories

3:33by saying the command CD

3:35and the directory in which I want to go to

3:37is going to be the root directory,

3:39which is this forward slash.

3:41If I now hit enter, we switch to the route directory,

3:44and if I do a listing of that directory here,

3:47we can see here a whole bunch of different directories.

3:50Now we will certainly see some of these directories

3:52in much more detail as we progress,

3:54but let me just give you a high level overview

3:57of some of the more important ones right now.

3:59Now the first thing to say for a good help

4:01if you happen to be confused,

4:03a good resource once again is by utilizing the man page.

4:06So if I take the command man

4:08and then say, hier for hierarchy, and to enter

4:12this actually gives us a description

4:14of the file system hierarchy.

4:16Now you'll notice here it says a typical Linux system,

4:19so not everyone is going to have this.

4:21And if you continue to press space bar,

4:23you can scroll through more and more of these directories

4:25if you so wish.

4:26But once again, the information here

4:28as presented in the man pages, it really is quite verbose.

4:31Let me just tell you about some of the more common ones

4:33that I would like to focus in on.

4:34So once again, we'll press Q to quit.

4:36So I'll do a listing once again.

4:38Let's first start with say the BIN directory.

4:41So the bin directory, as the name might suggest,

4:43is all about binary files.

4:46Basically, these are executable programs

4:48that your system can utilize.

4:50So if we do CD and go into the bin directory,

4:52let's do a listing in here.

4:53You may notice if you scroll through the outputs,

4:56you can see things like the LS command

4:59or perhaps maybe the CD command.

5:01These are actual Linux commands that your system can use,

5:04and this is where these binary executables happen to reside.

5:08So once again, I go back to the root file system.

5:11Let's do a listing.

5:12Let's now take a look at the boot directory.

5:14Once again, the name itself

5:16happens to be pretty descriptive.

5:18This is where you can find files

5:19that are used for the booting of the system.

5:22So go into CD boots, do a listing.

5:24Like I say, what we have here

5:25are a whole bunch of files relating to our booting.

5:28So things like the initramfs image once again,

5:31something we'll talk about later on within this course.

5:34Let's go back to the root to do a listing once again.

5:36Next we have our dev directory, which we can see right here.

5:39And the dev directory

5:41is where we can locate particular device files

5:43that are going to be used by the operating system

5:46so that it can talk to specific hardware,

5:48i.e devices like, oh, I don't know,

5:51like a USB drive perhaps,

5:53or an external hard drive connected to the system.

5:55If we plug in that USB,

5:58then our system will use the files

6:00within this directory here

6:01in order to facilitate that communication.

6:04Next, we have the ETC directory,

6:07otherwise known as the Etsy directory.

6:09And what this actually houses is system configuration files.

6:14So say for example, I go into the Etsy directory,

6:17let's do a listing.

6:18I have a directory for Firefox,

6:20which happens to be the browser installed

6:22on this graphical desktop environment.

6:25Inside of this directory

6:26is going to have particular configuration files

6:28relating to that browser.

6:30This is a system way configuration

6:32that would affect not just the IPV zero user,

6:35but also any other users on the system too.

6:38Once again, let's do a listing.

6:39Here is our home directory,

6:41and once again, this is an appropriately named directory

6:45because this is somewhere we can keep our personal files.

6:48It literally is our little home, so to speak.

6:50So maybe you want to write

6:51your own little programming scripts,

6:53or perhaps it's where you want to keep your documents,

6:55or your own pictures,

6:57or perhaps your downloads.

6:59This really is somewhere for your own personal files.

7:02Now, like I say, this acts as a personal directory

7:05for you as the user.

7:06And what actually happens

7:07is that for all the users on the system

7:09within this home directory,

7:11they will have their own directory within here.

7:14Now, typically that directory is going to be the name

7:17of their username.

7:18So right now, if I go into this home directory right here,

7:21if I do a listing, the only user we have on the system

7:24happens to be ipvzero.

7:26So ipvzero actually has a directory here.

7:28And if we go into that directory and we do a listing,

7:31we can see we have a folder for documents,

7:33a folder for downloads, a folder for pictures,

7:35so on so forth, a personal place for that particular user.

7:39So we go back to the directory.

7:41Let's clear the screen, do a listing.

7:42Here we can see the Lib directory as well as Lib64.

7:46Inside of Lib are basically a bunch of libraries,

7:50hence the name.

7:51And these are libraries

7:52that the system happens to need to operate.

7:54So say for example, the binaries found in bin,

7:57they can utilize the libraries found in lib.

8:00Next, we go into the media directory.

8:03Say for example, you want to plug in a USB drive,

8:06or some other type of removable media.

8:09This particular directory here

8:11is where you've been mounting this USB

8:12to make it accessible.

8:13Similarly, we also have the MNT directory

8:17or the mounted directory.

8:18This is also used for mounting,

8:20but this is more typically used

8:21to temporarily mount an actual file system.

8:25The next one we have is the op directory.

8:27Quite simply, this is where optional third party libraries

8:31tend to be stored.

8:32So as we're going to see later on

8:33when you happen to install particular packages,

8:36very often the actual files that are pulled in

8:39happen to be stored in this location right here.

8:42The next one is the proc directory,

8:43which is where we can find information

8:45relating to processes running on our system.

8:48One thing to note about this particular directory

8:50is that it happens to be a virtual directory

8:53that is just created in memory

8:54when the system happens to boot.

8:56So if you shut the system down,

8:58this here does not exist on disc,

9:00but once you reboot the system back up,

9:02it's going to regenerate this file system

9:04and pull information relating to those running processes

9:07as well as some additional kernel information.

9:10So if you happen to create a new process

9:12on your Linux system dynamically,

9:15automatically information is going to be generated

9:18and stored within this directory right here.

9:20Next we have the root directory.

9:22Remember I said, don't confuse yourself

9:24with the forward slash and the root directory.

9:27The forward slash is the true parent directory

9:30for all other directories,

9:32whereas the root directory is much like the home directory

9:36in that it's a personal space, so to speak,

9:39but it's a personal space for the administrator accounts.

9:42So not for the user accounts like IPV Zero

9:45or if I created a new user called Simona.

9:47IPV zero, and Simona would have directories

9:51within the home directory.

9:52That would be their own personal space,

9:54but the actual root accounts,

9:56this would be separate for them entirely.

9:58So the semantics can be a little bit confusing,

10:01because both would be referred to as the root directory.

10:04Just try to keep that distinction in your head.

10:06The run directory is going to keep information

10:08relating to runtime data.

10:10So say for example, things like users

10:12who happen to be logged into the system, that type of thing.

10:14The sbin directory, much like the bin directory

10:17is going to have binary files, these executable programs,

10:21but these are going to be the system wide binaries.

10:24Pretty much this is going to be related

10:26to your sudo command, the super user elevated privileges.

10:30The next one I want to talk to you about

10:32is the temp directory.

10:34This is a place designated for temporary files.

10:37Very often the information within this directory

10:40is going to be white when the system is rebooted.

10:43Next we have the user directory.

10:46This is going to store system wide read only files.

10:49And the last one I want to talk to you about

10:51is the VAR directory.

10:53Pretty much, once again, the name is quite descriptive.

10:56This is where we're going to store variable data.

10:58So pretty much data that is going to be well varying

11:01and changing.

11:02So things like logs, for example,

11:05something that's going to be continually being written to

11:08and updated and varying,

11:10or perhaps things such as mail messages

11:12that are continually being updated as new mail comes in.

11:15So these are some of the basics

11:17behind the file system hierarchy standard.

11:19Like I say, they do not always have to be the exact same

11:22across all distributions,

11:24but by understanding these basic concepts,

11:27where to find what and what directory,

11:29that is going to make you much more comfortable

11:32navigating the Linux system.

0:00[Instructor] Okay, friends, so here is the scenario

0:03to validate what we've learned here.

0:04Now, what we're going to see here

0:06might be a little bit challenging,

0:08but it's been done so by design.

0:10Let me walk you through it.

0:11The first thing I want you to do

0:12is to power on your virtual machine.

0:15Then once that is done, log in with your own user account

0:19that you have created.

0:20Then what I want you to do is to open a virtual terminal.

0:24After that, I want you to go to the directory

0:26that is used as your user's own personal space.

0:29Recall, we talked about all the different directories.

0:32Try to remember the one that was used

0:34for the personal space,

0:36and here is the more challenging part.

0:38Once you have navigated to that directory,

0:41I want you to list the contents of that directory

0:44whilst also displaying the inode number for each file.

0:47Now, this part here is the part

0:49that is a little bit confusing.

0:50Right now we have not described

0:52what an inode number is at all,

0:54so if this is completely confusing to you,

0:56that is absolutely okay.

0:58That is not the purpose of what we're trying to do here.

1:01We will definitely discuss what inode numbers are

1:04in due time, but I just want to put you

1:06in a challenging situation

1:07and try to recall how we might be able

1:10to find this particular piece of information.

1:13Because even if you don't know what an inode number is,

1:16if you just follow along with what we said

1:18within this skill, hopefully you should be able

1:21to find out how to actually display this information.

1:24So by all means, power on this virtual machine,

1:27give this task a thought,

1:28and I will see you in the next video

1:31where we discuss the solution.

0:00<v Instructor>So friends, let's walk through this solution.</v>

0:02So what I will do is I will power on my machine.

0:04Just hit the button here.

0:06Okay, so here is my username.

0:07I will just click on this, type in my password to log in.

0:10Perfect.

0:11Now that I've logged in, I'm going to go up

0:13to activities up here

0:14and then I'm going to choose the terminal.

0:16This is how I can open a virtual terminal.

0:19Now remember, the first task was to go

0:21to the directory whereby you would keep your

0:23own personal files.

0:25Now here is the thing, by default, you will already be in

0:29that particular directory,

0:31but I never told you that beforehand.

0:33So if you knew that you didn't have to change directory,

0:36then double bonus points for you.

0:37But let's walk through the process

0:39that we saw earlier on within this scale.

0:41Where do we know that we can go to see all

0:43of the directories within the file

0:46system hierarchy standard?

0:47We can go to the root directory

0:50and recall that is not the word route.

0:51That is actually the forward slash root.

0:53So if we say CD forward slash,

0:56and now I do a listing of all those directories.

0:58Here they are right here.

1:00Now which one will I go to for me as the user IPV zero

1:03to find my own personal space?

1:06Well, that is going to be in the home directory.

1:09So if I say CD home

1:10and I do a listing again, I'm going to see a directory

1:13with my username on it.

1:15Now you at home no doubt, will have a different username.

1:17So all you will do is say CD and then give your username.

1:20So if I just say CD IPV zero,

1:23now I'm in my own personal working space.

1:26Now the challenging part was here is

1:28that whilst we are in this directory,

1:30we want to create a listing of the contents within here.

1:33Now recall the command

1:34that I was using throughout this scale

1:35to actually show you the contents

1:37inside the directory was the LS command.

1:40This is for listing.

1:41Now I added a rather strange and peculiar request.

1:44I also said that we wanted to list the inode information.

1:48Now again, we don't really know what that is quite just yet,

1:51but let's suppose we come to the examination

1:53and there is also something

1:54that you're a little bit unsure of.

1:55What tool can we use to help us find this information?

1:59Well, we know we can use the man page.

2:02So if you want to list something,

2:04let's look at the man page

2:05for the list command, which is as we know LS.

2:08So I'll say man, LS,

2:10and whilst else we are in here, we can press the space bar

2:13to go through all of the pages.

2:15But to make things easier, why don't we just search

2:17for the word inodes?

2:19Now, how do we actually do that?

2:20Well, we can do that recall

2:21by doing the forward slash, which we can

2:23see in the bottom left now.

2:25And if I just type in the word inodes

2:27and hit return, that actually snaps me to the option

2:30that I can use with this command in order

2:32to print that inode number.

2:34So what I can do here is say LS dash I

2:37or if I so wish, LS dash dash inode,

2:41either of which is going to work.

2:42So what I will do is I will press Q to quit

2:45and if I say LS, we get a regular listing.

2:48But if I say LS dash I

2:51and hit enter, now we are successfully printing the contents

2:54of this home directory, this personal private space

2:57for us as the user with those associated inode numbers.

3:01So even though we don't know what inode numbers are quite

3:03just yet, hopefully you were able to figure out that perhaps

3:06by searching the man page

3:08for the LS command we could find information relating

3:11to the inode information.

3:13But if you did not get the solution,

3:14then definitely do not worry.

3:16We're going to study all of this content in a lot more

3:18detail as we progress throughout this course,

3:21but for now, that is all

3:23for getting set up on a Red Hat Linux

3:25enterprise environment.

3:26I hope this has been informative for you

3:28and I'd like to thank you for viewing.