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Hey guys and welcome back. So in the previous nugget we discussed how we could manually

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mount our fail systems but we did notice that we did not have any type of persistence. A

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simple reboot would simply just unmount the fail systems we mounted with the mount command.

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You might have noticed that despite the reboot some of the file systems did persist. Say for

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example we do an LS BLK-F we can see this one here is still mounted as well as this one right

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here. So what is going on? Why are these ones mounting and the other ones are not? What it comes

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down to is a very very important file and you really want to be remembering this file. It is the

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in fact let me just type cat the etsy fs tab file really really really remember this file.

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So if I open this up in fact let me go in via nano instead so we can get the color highlighting.

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Okay right so let me tell you what's going to happen when the system boots up the mount command

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is going to be issued but it's going to be issued with a very particular flag it's going to be issued

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with the dash a flag so mount dash a. Now what this is going to do it's going to mount all of the

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file systems that have been defined to mount within this particular file right here. So what we can

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actually see here are a bunch of different columns now I will admit the way the columns have been

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formatted is really quite ugly it is quite difficult to actually follow which column is which

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but let me walk you through it quite briefly. Now the very first column is going to be the

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file system uuid okay so this is the uuid for my sda5 the reason why I know that is because I can

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see the very next column which is the mount point and by the way if you want to be able to correlate

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what I'm looking at first column is file system next column is mount point so I happen to know

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the mount point here is root which correlates to my sda5 the next column is the type and like I say

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the formatting here not so good the type is going to be this one here ext4 that is the file system

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type and then we see the mount options we briefly mentioned what this was all about so we can see

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here what's going to happen is on error we will attempt to remount using read only now we do have

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these other options here dump and pass I'm not really going to dive into the details of what

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those are right now and below we can see the file system here identified with the uuid again this

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is mounted at boot efi that's going to be my sda1 partition we can see the file system is vfats

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we can see the mount options and we can see for dump it's got the value zero and pass it's got the

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value one okay so check this out what this means then is that if I want to mount my file system in

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such a way that it will be auto mounted upon a boot up then I don't just want to use the mount

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command I actually want to put that information within xafstab that means when the system boots

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up and runs that mount dash a command if my information is within this file then it will

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be mounted now the first thing to notice here is that this is unrightable that is because I didn't

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use my super user privileges so I'll just exit back out here further now and I'll say sudo nano

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xafstab type in my passwords okay so what I will do here is I can specify the uuid or I can just give

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the device type so that means I can just specify if I so choose dev sdb1 which is my device type

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and then I can specify the mount points my mount points here is going to be home ipv0 and the backups

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directory and then the file type I'll say is ext4 with respect to the mount options I'll just specify

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the defaults and then I'll give the value zero and zero for my dump in my pass if I happen to

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write this save you and I exit out I do my lsblk-f notice right now that the system or rather the

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file system should I say is still not booted that is because we need to run the mount dash a command

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or we could alternatively reboot the system which will automatically invoke that command being run

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so I'll say sudo mounts dash a if I rerun my command notice now we have actually mounted sdb1

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and we've mounted it within home ipv0 backups and again if I reboot my system in fact do my sudo

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command sudo reboot what's going to happen is my system will reboot and it's rebooting as we can see

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okay dog so my system has booted backup I do an lsblk-f and notice the sdb1 device that is

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mounted now the mounting is now persistent that is because like I say the information has been

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updated and included within the xcfs tab file so very very important to understand that difference

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now one thing I do want to mention before we end this nugget is that we can also use system d with

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respect to mounting and unmounting our file systems so like I say we have our lsblk-f command we can see

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we have this device mounted if I wanted to use system ctl to check this what I could do is I could

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say sudo system ctl and I can specify the status and then I could go into home ipv0 and backups

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basically just checking the mount point I'll have to type in my super user password and notice it says

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that this is active and mounted we can also see what it is i.e the device and if we wanted to

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unmount that what we could do is we could change the option from status to stop and if I try status

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once again notice it is no longer mounted it is inactive and dead that means if you run lsblk

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we can see it is no longer mounted but check this out if I just say start and give it the same mount

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points and hit enter notice it has mounted but check this out how did it know which device to

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actually mount I just gave it a mount point how did it know to actually mount sdb1 but what happens

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is that if we go into cd and run and then system d and we want to be remembering this location here

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by the way and then into generator within here we actually have a whole bunch of files see these

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dot mount files these are the unit files which contain such information so if I try to mount

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into home ipv0 backups system d is going to look for this mount file if it has already been created

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which it has so if I go into here and I open it notice the information is right here it says

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whereabouts we should mount it what we should mount i.e the device and the file type you see that

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similarly if we look at the other mount points we can see we have our bootefi dot mount i can say

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so I can say nano bootefi dot mount we can see here that is going to be type vfats and in this case

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here it's just been identified by the uuid as opposed to sda1 so really what we want to be

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remembering within this nugget right here is that if we want to have persistence we really really

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really want to be remembering the name of that file say fs tab as well as knowing that we can use

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system ctl to mount particular file systems as well as check their status and unmount them and like

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I say the way system d can do this is by tracking this information within the run system d generator

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directory and look for those dot mount files okay docs I hope this has been informative for you

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and I'd like to thank you for viewing