System backups, there are many different ways you could do system your your system backup, but one
particular way that I wanted to cover in this lesson is through the d'Yquem.
It did come in comes all the way the beginning when they started doing the backups on tapes.
So that's when they would run the command.
So basically there are five different type of backups in every system.
The first type of backup is the actual entire system backup, where you take the entire image using
tools like a third party tools.
People have built third party tools and such as a Crannis VM com world and many other different software
out there.
One of them is also that it worked in the past was net backup.
So just like that, there are so many software people have or build and sell to the companies that allow
them to perform system backups, and that is to again, to create the entire system backup and put it
like an image, just like an eyesore of an entire system.
And whenever there is a need, it does the restore of everything and put it into the same existing system
if it has crashed or to a new system.
The second type of backup is the application backup application.
Backup is are the ones like you have your Linux machine running, right.
Or even Windows machine running.
That's an operating system.
But you use that operating system to have some kind of application install on it.
Right.
So, again, as I said in the very beginning, that the the purpose of a hardware is to have the operating
system on it.
And the purpose of having an operating system is to run certain applications.
So that's the primary reason we all use the computers.
So anyway, the second type of backup are the application backups, any time any application that you're
running in the system.
So to do the backup of the application, most of the people use the third party application solutions.
Then we have the database backup.
So if your system is running any kind of database, for example, Oracle or Ski Well or Informix, most
of these companies who actually deal with database or provide databases also provide a backup solution
for that database.
For example, Oracle has a solution called data card and ask you would have a solution for Ezekial backup.
What does the backup of the entire database now remember, this is not the backup of your file system
or even if your system this is a backup of only the data that is being generated by the application
are running on your system.
OK, so the fourth type of backup is the file system backup, the file system backup, meaning backing
up your files, your folders, your directories, and you could use the commands for those type of backup.
And those commands could be like Tor Cheesa to compress it, compressed the entire directory.
And then you could once you have a backup with the Tarbell, you could actually transfer it to another
machine or copy it to a remote machine.
So in case you need to restore your file or directory, you could go back to that Tarbell and extracted
from that zip file.
Now, you could use them manually as a matter of process to store and transfer to another system.
If you do not have a professional third party product to do that for you, if you do have a third party
backup software, then most likely those third party backup software would also let you do a PA system
back.
The fifth type of backup, which is the main concern for this lesson, is that disk backup or doing
a disk cloning using the D command.
What is a disk backup or disk cloning will.
If you think of it as if you have a desk, right, that's just a physical desk and it is, let's say
one hundred and forty six gig of desk, and it has all the data inside file system, partition or whatever,
when you use the command, you could actually copy or clone the entire disk and clone it to another
desk.
Now, keep one thing in mind that command does not know what's inside of that clone or what the file
looks like it would be.
Even if you try to open that file, it will be just a garbage.
You won't see anything.
So it actually does the file does the backup of your entire desk and put it in some kind of image,
either just an image file or ISO file and exactly takes that exactly.
The disk copy or image or snap off your desk and put it and slap it on another desk.
So this is what we're going to do in this lesson.
So D.D. is a command line utility for Unix and Unix operating systems was primary purpose is to convert
and copy files.
As a result, DD can be used for tax, such as backing up the boot sector of a hard drive and obtaining
a fixed amount of random data.
Moving on to back up or clone an entire disk to another hard disk connected to the same system, execute
the dead command as shown below, and the command is dead if equal, the source file name if you have
a source partition or a source disk to which in this case we don't use the to use of equal target filename,
which could be the file name itself or the disk or the disk partition.
And then you could also use different options that are available would come in as an example, if you
see right here, it could look like this if equals Saeda or Step CDB.
What this is doing right here is it's copying right here is copying the entire disk, not the partition
of the entire disk, which is as dieser and actually slapping it or putting that entire image on CDB.
But also, keep in mind, if you are copying SDK, which is two gig and copying it over CDB, which
is one gig, then it's of course is not going to work.
Make sure the LDA and WB both have the exact same size disks to copy.
Back up the disk partition.
Now we are talking about partition.
You know, each disk could have multiple partitions.
You could use a command like Deedes if Dev as D one and copy it to an.
A disk or a file system using the name of the file, we could use a name, as does one dot image.
Now to do the restore, restoring this image file to the machine after copying the AMG, meaning if
you already have this command ran and you already copied this interpretation and you copied it and named
it and one dot img and you put it in.
Now once that copy or deed cloning process is done, you could take this image and transfer over to
another machine.
If you wanted to copy the entire content.
Once it's transferred over to another machine, then you could run a command on the destination machine
as if slash as one and you could put it on SDB three or four or whichever partition that you want to
put that system on.
So that's how the document works.
Let's try it out.
Practical how it looks like on our Linux machine.
OK, so I am logged in as myself, I am in full directory and in the correct server to run the command,
you will have to be rude.
OK, so in my example, that CD of minus H, let's say if I wanted to.
Copy.
Let's say this slash.
Boot, which is about the size, is one gig, I want to copy this partition to another desk, which
is CDB one.
Slash data.
So what I could do is, Dee, if.
Sorry if equal.
SD, a one two will copy over to.
Data, because I'm doing the petition, I'm not copying the disk to disk, so if I were to copy disk
to disk, I would do dev SDA, so I CDB one.
So this is copying partition to partition.
Sorry, if I'm copying disk to disk, I'll take either the one and I'll take the one here.
So anyway, I'm copying partition.
To.
File system, which is data.
And I want to call it, but I M.G., to this, the image of the Butat and you enter OK, it says unrecognizable
Mendieta.
Oh see I missed one thing I did not specify off equal.
It's OK.
It happens.
Even people like me make mistakes, that's fine.
OK, so enter now.
OK, now you see it is actually working and the reason it's working is because you did not get an error
message right away.
Now, depending on the size of your source, the size of my source is you see here is used as one 57
and the size is one or one four.
Now you probably thinking, hey, this partition is only has one 57 meg.
And why is taking that long.
Well, and you do decommission.
It does not care what is used and what is available.
It only looks for the size which is this.
And it thinks that this is the complete size.
And I'm going to copy this size exactly as this.
As you can see right here says, this is the size one point, one get copied.
See, it does it it doesn't care what is used and what is not used.
It thinks of it as, oh, I'm going to take a snapshot of this entire disk and that's it.
Now, it did copy it.
Now let's verified it because it copied it to.
Data slash, boot image you hit enter, you'll see this is the size of the copy.
Now you have a copy of your boot.
Now in case something goes wrong to your system or your boot file system gets corrupted, you could
actually do this and restore hair.
And to do the restore, you would have to do if.
Equal data slash boot image.
Where to, Deb, Estie, a one that's how you would do it, but I do not want to do it.
I don't want to mess up my system right now.
It's just a lab.
But, you know, I wouldn't recommend you to try on your on your production system as well.
But if your system is down, then that's how you will recover your PA system.
But you do.
What you could do is you could try to do that to another PA system if you have a file system that is
not that is just used for testing anyway.
So this is how the command works and this is how that command is used to perform system backup to do
the disk copying or disk cloning.
Again, I'll go back real quick to my previous slide.
There are five different type of backups and that is something that you should know.
What are the different type of backups and how backups are performed?