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- In this video, I want to
explain the concept of mount.

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So, there's this thing called
the Linux directory structure.

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starts with the root directory
and below the root directory

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you have your directories
like boot and home and VAR

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and MNT.

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And so on.

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Now, the Linux directory
structure is always the Linux

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directory structure.

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And it's independent of
the devices that you are

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using inside the Linux
directory structure.

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In order to use specific devices,

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you will mount the devices
and by mounting the devices,

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you connect your device to a
specific directory structure.

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So, if we would have a device
with the name, Dev SDA1.

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Which is a typical name
for the first partition on

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a hard drive.

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Then you can mount it, connect
it to the root directory.

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And that means that
anything that you write to

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files somewhere in the root
directory, will be written

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to this dev SDA 1 .

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If you have a USB thumb
drive and you want to

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access your USB thumb drive.

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You can connect that to the MNT directory.

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So, you would've a new device.

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Typically that will be
slash dev slash SDB one.

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So, you mount your SDB
one to the MNT directory.

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What is the result?

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The result is, if your right
files to the MNT directory

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then really the files end up
here on your SDB one device.

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And at the moment you, you
mount you disconnect your

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SDB one device, the files
that you've just written

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to it are gone, because the
mount is no longer there.

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Mounts on Linux are pretty
important, and you will notice

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that Linux is using different partitions.

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And these partitions are mounted
on different directories.

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There are several reasons
why you want to do that.

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I'll explain it later.

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All right.

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So, what have you just seen?

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Let me summarize. LSBK
is a convenient command.

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It lists block devices in any mount starts

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with a block device that is
connected to some directory.

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the Mount command is convenient as well.

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It lists all the current
mounts, but in the Mount command

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you will see a lot of
output that is unnecessary.

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Another way to see what
is currently mounted is

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DF minus H.

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DF minus H, not only
shows the mounted devices

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but it also includes available disc space.

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And finally there is
find MNT which is just

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a nice representation of the
output of the Mount command.

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Let me show you how to
actually mount a device.

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So, in order to do this demo,

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I am going to mount USB thumb
drive on my, on my laptop.

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(computer rustling)

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So, here we have my
virtualization program kicking in

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and I know this is not a
course about virtualization

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but you probably are using
a virtual machine as well.

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And then your virtual
machine might ask where

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you want to connect the device.

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Well, I want to connect
it to my Centos stream

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virtual machine.

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And then we can continue
on the Centos stream where

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I'm using LSBLK and
LSBLK is showing me what?

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It's showing me nothing.

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So, it doesn't work.

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So, here in my virtualization software,

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I found this option to
connect unknown manufacturer

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of flash disk.

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And that's exactly what we need.

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Sometimes the virtualization
software requires you to

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do something in addition.

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And here we can see that
the graphical user interface

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is automatically reacting.

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That's good, but this is
not of course about gooey.

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So, let me click this away.

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And let's analyze.

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I'm typing LSBLK and
LSBLK right now is showing

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that we have dev, a
device with the name SDB.

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SDB is the name of the second disc device.

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Normally SDA is your first disc device.

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I will tell you more about devices later

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because the name of the
device really depends

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on the hardware that you are using.

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Now, my graphical user
interfaces automatically

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mounted the device for me, and guess what?

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I don't want that.

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So, I'm going to use Sudo umount dev SDB.

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Mounting from the command
line requires sudo privileges.

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Next I'm going to use
Sudo, Sudo mount dev SDB

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and I want to connect it
to the slash MNT directory.

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So there we go.

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I'm connecting it to the slash
MNT directory, by the way

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because according to the
file system handling standard

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this is where you should mount
all your temporary mounts.

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So, if I'm checking the
contents of slash MNT,

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we can see.

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Wow, that's a lot of file.

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It's only one file but
that doesn't matter.

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So, if I would copy ETC
pass WD to slash MNT,

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I'm using LSMNT again,
now we have two files.

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But this file, and that's
the point I want to make here

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is really written to the USB thumb drive.

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And we will see that it
disappears once we have unmounted

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but first, a couple of commands, LSBLK.

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I like using LSBLK, because it's a clean

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overview that is showing
the device and where the

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device is mounted.

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It's only showing your block devices.

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In the past you will be
using the Mount command

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but the Mount command,
nowadays is showing a lot of

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administrative mounts as well.

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And it's true in the last
line, we can see this

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dev SDB device but the
problem is that you need to

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find it between MQ and huge
TL, BFS, and trace FS, and

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many more Linux internal mounts
that you don't care about.

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(clicking)

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Another command that's
convenient is DF minus H.

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The DF stands for Disc
Free and minus H is given

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a human readable format.

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Without a human readable format.

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It would look like this.

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It's showing the size in blocks

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and that's not very readable.

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Most people prefer the
human readable format.

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And there we can see not only
where the device is mounted

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but also size still
available on that device.

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And finally, there is find MNT.

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find MNT is giving you this.

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It's a nicely formatted
overview of the directories.

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So, it's really focusing
on the directories and you

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will see where in the
file system hierarchy.

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We have a directory that is
mounted to somewhere else.

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So, we have boot that
is mounted on SDA one.

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We have MNT that is mounted on SDB.

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We have proc that is mounted
on the system device "Proc".

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And we have slash which is
mounted on dev mapper CS root.

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Again, I will tell you more
about the storage devices

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and how they work later in this course.

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But for now, at least, you
know how to connect USB thumb

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drive.

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One more thing remaining.

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And that is Sudo umount slash MNT.

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Umount is what you need to
do to disconnect the device.

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If you just pull it out

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then you risk losing data that
has not yet been synchronized

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to the device.

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And if you use Umount then
you synchronize everything to

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the device to make sure
that it's really stored on

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the device.

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Now, I'm using LSMNT.

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And as you noticed, I don't
see host or pass WD anymore.

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That is because the device at
this point is disconnected.

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That's how you mount devices.