Mounting Filesystems in Linux! (Linux+ Objective 1.3.3)

hey everybody I'm Sean powers and in

this video we're continuing our Linux

plus certification prep we're talking

about mounting file systems and this is

one of those videos where I could go

super deep into so many different

aspects of mounting file systems but

what I'm going to do is I'm going to

cover enough that you will understand

what you need to know for the exam and

if there are areas that I think might be

interesting for you to dive deeper into

I'll try to mention it along the way

we're currently in objective 1.3 on the

Linux plus objectives I'm calling this

1.3.3 this is our third video as we

explore this objective and like I said

specifically we're going to look at

mounting local and remote file systems

or devices and remote devices is

important here because we're not talking

about remote file systems like over the

network we're going to talk about that

over here specifically remote devices

are like externally attached like a USB

drive that sort of a thing so we're

going to cover the things in here

including encryption very briefly you

and that should give us a good feel for

what's going on and I don't want to

start this video without thanking

everybody over here you might notice

it's actually scrolling now because

we've had even another person who has

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makes me so excited to continue to make

more and more content whether it's

videos or whatever it is that you might

be supporting me for so anyway thank you

to my patreon supporters if that's

something you're interested in uh link

will be down below but let's get into

how we can actually Mount file systems

on Linux so just a quick rundown of what

I have set up in the folder MNT I've

created just three empty folders or

directories called drive one drive two

and drive three we're going to use those

as places to mount our drives or devices

so I have those things created and if we

look at LS

BLK I'm going to do Dash E7 which will

filter out all of those Loop devices it

will show us that we have of course SDA

is our system hard drive I'm not really

going to touch that that's the that's

what our ins our system is installed on

but I have some other devices here too I

have sdb SDC and sdd SDR is actually our

CD-ROM but I've created a partition on

each of these drives just one partition

that takes up the entire 10 gigabytes

okay now if we actually do another

command here Dash f it will show us what

file systems are formatted on there if

there are any so here you'll see sdb1

has an ext4 file system already put on

it SDC one has Butter FS BTR FS the file

system is formatted on it and sdd1

doesn't have any file system at all it's

just a raw partition we're going to use

that later for encryption so anyway

these two have things have a file system

already installed on it which means we

should be able to mount it into our

Linux file system so let's do that for

first of all with sdb1 and this is just

how we go about doing it manually so we

would say sudo because we need root

privilege now I say that it is possible

to have something set up so that a user

can mount it without root access that's

kind of Beyond where we're going to go

today that's like user mounting options

which has to be set up for individual

mounts we're going to use root access to

mount all of these drives onto our

system because at the end of the day it

requires root access but you can set it

up so that a user can initiate the mount

anyway we're going to be we're going to

have root access to do this so sudo

Mount and then the device that we want

to mount in our case let's do Dev sdb1

and then where we want to mount it uh

MNT will say drive one now I could add

another flag before I do this I could

say Dash t for what type is it and we

know that it's ext4 but that is almost

always Auto detected we very rarely have

to specify what type of file system it

is and in fact if it doesn't work if it

doesn't Auto detect the file system

chances are there's something wrong and

it's not going to mount anyway so I'm

not going to put that on there but if

you see somebody specify Dash T and then

the file system type that's why it's a

way to tell Mount what kind of file

system to expect

but you can see it usually Auto detects

it just fine if we do it if we do a DF

minus H we're going to see that now we

have this device mounted on MNT drive

one and it's able to be used now on our

system it's part of our file system now

mounting things manually is great but

it's really not that practical

especially if it's hard drives that you

want to have automatically Mount when

the system boots up and so generally

what we do is create entries in the ETC

FS tab file which file system tab so

that's what I'm going to show you how to

do right now is how you would make

amount permanent on the system so let's

unmount this drive and to do that sudo U

Mount it's not on it's not unmount it's

U mount for unmount which is a little

confusing sometimes but you mount and

then MNT drive one so then it will

unmount if we look it's no longer

mounted on our system so let's look at

Etc FS tab here is where we can make an

entry and there is a little cheat sheet

up top here that will explain how you

can specify what you wanted to mount

when the system starts up so the first

field is what file system and that can

be specified in a number of ways in fact

it's specified a couple ways right here

you can see uuid equals and then this

euid that can be how we specify it we

could just use a device like Dev sda2 we

could use a label that we have formatted

on the partition so there's a lot of

different things that we can specify as

what file system is that we want so in

this case let's actually I just did the

device on the command line so let's get

out of here really quickly and if we do

sudo

blkid and I'm going to get rid of all

the loopback devices this will show us

all the partitions on our system and the

one that we were just looking at is Dev

sdb1 and so this has a uuid of this

right here now point out right here

since we're since we're looking at this

block ID information this is the uuid

this is the unique Universal unique

identifier for the file system that is

installed however there's also the

partition uuid which is pointing to the

actual partition on the hard drive that

the file system is written to so if you

and that if that seems confusing

hopefully this will help if we look down

here at Dev sdd1 you may remember this

is a a partition that does not have a

file system put on it yet and this still

has a part uu idea partition uuid but it

does not have a uuid because there's no

file system formatted on this partition

yet okay now the cool thing is we can

actually specify in file

Etc fstab using either uuid or part uuid

generally you'll see this done either by

the device which in our case is going to

be Dev sdb 1 or the uuid so let's let's

do this uuid this is going to be that

device copy and now if we do sudo VI Etc

FS Tab and now I'm going to paste that

so that's the file system this is the

device this is that first field and then

where we want it to Mount that's just

going to be MNT drive 1 the next field

is the type so here we do actually have

to put the file type which is or the

file system type which is ext4 and then

the next one is what options I'm just

going to say defaults we don't need any

specific options in there and then the

next two are a little bit confusing dump

is very rarely used at all anymore so

we're going to put a zero here what dump

is talking about is you could do like a

file system backup it would like dump

the contents of a partition or a mounted

device it's just not done anymore it was

dump FS it's just not done anymore so

zero means like no we're not going to do

that and then pass talks about how often

you want to do a a file system check

we're going to look at file system check

in probably the next video but there's

three options let's see there's zero one

or two zero means don't do any file

system checks one means I want you to do

file system checks and this is the root

partition well this is not the root

partition and so two would be I want you

to do file system checks but this is not

a root partition all right so I guess

this would be the way to go either a 2

or a zero I'm just going to leave it at

zero then we save this

and now when the system boots up it will

automatically Mount that onto Mount

Drive one but if you look right now it's

not mounted so we can say sudo Mount

Dash a which will re-read that FS tab

file and mount all the things that are

in there so if we do that and now we

look now it's mounted and it will Mount

every time the system is rebooted now

the Linux plus objective specifically

says external devices which is a little

bit of a weird thing it's not something

we do very often and this makes me think

of a USB drive now if it's like a USB

stick most distributions especially if

they have a GUI installed will just

automatically mount it when you put it

in and then you take it out it's you

know unmounted however let's say you

have a like a really large

USB drive it's like an external you know

USB like I don't know 20 terabytes or

something and you want to have it

treated like a regular hard drive on

your system but it connects via USB well

it is possible to actually have those

treated it like a regular drive so

that's what we're going to do we're

going to set up a USB drive so that it

doesn't automatically Mount and unmount

when we plug it into the USB connector

but treat it more like an internal hard

drive on our system and here's the thing

normally when you plug in a USB drive

and I have one just out of camera here

it will do what it just did here it will

automatically Mount that USB stick and

if we look down here DF minus H it

mounts it somewhere like in the media

folder and this is the auto mounter that

looks for USB drives and it will do that

automatically but let's say like like I

just discussed that we want this to be

treated like a regular hard drive well

let's do let's unmount it first so

umount media s Powers USB stick now

let's do a sudo BLK ID corrupt Dash V

Loop and let's see if we can find that

device yes it's right here so Dev SD E1

is that partition I unmounted it but

it's still inserted into the system and

so we can create an entry in ETC FS tab

for this and now remember I said we can

specify these based on a lot of things

like a device the problem is with a USB

device specifically let's say we plugged

in another USB stick before this one and

so the other one was sde and then this

one was SD F so using a device name

particularly with something that might

change is not a great idea so in this

case we would either want to use the

uuid which you know we have uuid or you

could use a label and for something like

this I would probably use a label my

rationale here is that you can actually

label different USB disks the same thing

and so if you always want your USB drive

to mount in the same spot you could just

label them the same whichever one's

plugged in is going to be there but

nonetheless label is one more way we can

specify it let's take this label USB

underscore stick

Etc fstab

and the same thing as before we're just

going to make another entry this time

though we're going to say label equals

USB underscore stick

and then I want this one mounted in MNT

Drive 2 and this is going to be well

what was the file system on there let's

look I'm going to go back and look it

looks like a v-fat so this is a it's a

Dos based thing basically so the type is

v-fat it's right here so we'll go back

in and V fat is our type defaults I'm

going to say 0 0 again

save this and now again it's not mounted

because we you mounted it however if we

were to say sudo Mount Dash a now all of

a sudden that drive is going to be

mounted in Mount Drive Two And now when

we reboot the system as long as that USB

drive is in even if it's not recognized

in the same order it should mount on

that location instead of uh us having to

like put it in and have it Auto Mount

detected by the GUI operating system

that sort of thing it should be treated

just like a regular hard drive on the

system and mount app boot but you want

to know a little secret system D

actually does all of the mounting the

ETC fstab file used to be where

everything was read from and mounted

right from there but not anymore now

systemd looks at our FS tab file and

creates on the Fly individual

um system D Mount files and that is what

it uses to mount them let me show you if

we go to our system here and we go into

run system d e generator and we look at

all the files in here we're going to see

a couple specifically this is the the

one that is generated on boot so the

dash here is just referring to the root

partition but here is the deal let's

look at it this is auto generated by

reading the fstab file and it creates

this file on the Fly and this is

actually how it mounts on the system now

we can create our own dot Mount files in

Mount devices into directories using

this method however this is not what is

generally recommended it's still

recommended to use the ETC fstab file to

spell out all of the mounts that you

want even though they're converted to

system D Mount files however it is

possible to use a systemdmount file if

you have a reason to do that and you

want to specify uh in a file like this

but to do that I'm not going to dive too

deep into system D but if you have

custom things that you create for

systemd they're going to be put into

Etc system D system this is where the

user generated files are put and there's

probably already a bunch of stuff in

here but we're going to create a simple

Mount file and we're going to put it in

here so I'm going to do sudo VI and this

is it has to be in a very specific

format okay it has to represent

by name where the end result is going to

be so we have to do something like v i m

n t Dash Drive 3 dot Mount because if

you remember I created that directory in

Mount Drive 3 and so we have to name the

mount file exactly this or it won't work

so we're creating this file I'm just

going to make it very very simple

Mount Drive three and then a little

Mount section what equals and then this

is the device that we actually want to

uh use so this is device the device that

we're going to mount so let's get the

uuid from a device pseudo okay ID crop

Dash V looped so the loops don't show up

and the device that I want to mount in

here is this one Dev SDC one and it has

this uuid for the file system so I'm

going to copy this

go back into here and this is a little

bit goofy this is kind of how you

specify it Dev disc by uuid and then

actual uuid so I'm going to get rid of

this stuff

so we specify that is what device and

then where is the next option here and

where is going to be Mount Drive three

and it has to be here because remember

that's what we named the file type

equals

btrfs which is what it said it was

options equal defaults and I don't know

if this part is required but generally

multi user dot Target and that just

means that it will call this uh when we

start multi-user mode on boot all right

so I'll save that

and now we have to do sudo system CTL

Daemon reload so that it sees that mount

file that we've created this is just

more systemd stuff and then we treat it

just like we would a service so we can

say pseudo system CTL start MNT Drive 3

mount

and now if we do DF minus H it's mounted

it right here now this will not

automatically start on boot because just

like a systemd service we would have to

do sudo system CTL enable

Mount Drive three dot mount

so we do that and now it will actually

Mount that on boot even though it's not

in our FS tab file so again it's

possible to do that and if you put it in

ETC systemd system and name it properly

it will mount on system boot but it's

still not generally the way that we go

about doing it normally we still use the

ETC fstab file because it's one place

that we can put all of our file systems

and that's will be converted

automatically so we don't have to worry

about the system D side of it and then

you only have one place to remember to

store all of your system mounts that

said the one last thing we have to cover

is an encrypted file system using Luke's

so back here on Ubuntu I'm going to

create one more directory I'm going to

make directory Mount secret we're going

to use this directory for an encrypted

file system now if you remember lsblk we

have these devices down here so the one

that we haven't messed with at all is

sdd1 this is a partition there's is no

file system on it at all so we're going

to create an encrypted partition and to

do that we use the Crypt setup tool so

Crypt actually I'm going to do sudo

Crypt setup Luke's format Dev

sdd1 so it's going to overwrite it

completely because it's creating uh this

encrypted partition so I'm going to it

says are you sure type yes in capital

letters so yes in capital letters now I

have to enter a passphrase okay this is

how it's going to decrypt if you don't

remember this passphrase your data is

lost right there's there's not a

recovery function if you can't remember

your passphrase so it's generally

something long mine is not going to be

really long and now it is an encrypted

partition but it's not open in order to

access the partition itself so that we

can write data to it we have to decrypt

it and open it in a decrypted state so

in order to do that we use the same tool

sudo Crypt setup but we say open and

then what the device is so Dev sdd1 and

then what we want it to be named in its

unencrypted state okay does that make

sense hopefully it does hopefully it

does we're going to call it secret disc

I have to enter the passphrase okay and

now I think it shows up with a LS block

sort of I mean it is called secret disc

but it's going to live in Dev mapper

okay in Dev mapper secret disc is that

currently decrypted file system so what

we would do is write a file system on

there because right now it's just a

an encrypted partition that's currently

open and decrypted and that's how we

access it so we're just going to do sudo

mkfs.ext4 I'm just going to make an ext4

file system on it Dev mapper secret disk

okay it's all done and now let's uh

mount it so we're gonna say sudo Mount

Dev mapper secret disc on Mount Secret

and now sure enough it is there and we

should be able to access it so let's uh

go into I'm just going to become root

Out secret okay there's lost in file

touch file.txt all right sure enough

it's there so let's get out of there and

now to unmount it we would do the same

thing backwards right we would just say

you mount mount secret okay it's uh no

longer mounted and then it's still

available in an unencrypted form though

so what we would have to do is say Crypt

setup close Dev sdd one just actually

the name of it which for us is secret

disc

okay and now we can no longer access it

without retyping in our password I know

that was a lot there's one more thing

that I it isn't really specified but I

do want to show you you can actually

automatically have it mount on boot and

it will prompt you during boot up for

the passphrase in order to continue and

actually Mount the file system on boot

there's also ways you can create keys

and have them stored in special places

like on a USB drive that you plug in but

let's quickly set up an automatic that

an automatic Mount that will prompt us

on boot to unencrypt the drive and then

we'll be done so let's do the okay ID so

this is our device let's get the uuid of

this device this is our crypto Lux

device itself so I'm going to copy the

uuid and what we need to do is when the

system boots up it will look in a file

called

Etc Crypt tab so we have to create this

file and in here we actually specify

what it is we want it to decrypt and so

the first field is what we want it to be

called in our case I want it to be

called secret Drive

and then the next field is going to be

that uuid of the actual Luke's partition

itself and then the Third Field is just

I'm just going to put a dash this is

where we could tell it like to have a

key that we would automatically decrypt

it but if we just put a dash here it's

going to prompt us for that passphrase

as it tries to create secret Drive okay

so that it should be all we need to do

and then if we look in FS tab

then we can assume that we've entered

our passphrase Dev mapper

secret Drive is going to be in Mount

secret and this is just ext4

defaults zero zero that should be all it

takes to get it to automatically Mount

after it prompts us for the passphrase

on boot so let's reboot the system and

see what happens

okay it's asking us right here for the

passphrase so let's put that in

all right we've booted up let's have a

quick look

TF minus H and we have drive one is

mounted drive two is mounted drive three

is mounted and Drive Mount secret is

mounted so all of the things that we set

up uh survived the reboot including that

one that we did with system D and

automatically mounting this by prompting

us for that passphrase on boot I know

that was a lot to cover and I encourage

you to look deeper into things like Auto

Mount because that's really fun but it's

not part of the Linux plus objectives

but anyway hopefully all this made sense

maybe you have to go back through and

watch it I encourage you to try it on

your own system to make sure that you

can replicate what's going on as we went

along doing it and uh this is another

example of how important it is to learn

everything do what you love and most

importantly be kind I know this is a

long one but I'll see in the next video