Course 8.
We're going to talk about the FAT file system.
Next slide.
An overview of what this course is going to cover.
We're going to talk about the history and versions of FAT.
We're going to talk about the data structures that make up the FAT file
system, things like the root directory and the volume boot record.
We're also going to talk about the directory structure within the FAT
file system.
We're going to talk about file and directory creation and deletion.
What happens when we create a file?
What happens when we delete it?
What occurs when we create a directory?
And what happens when we delete that directory?
We're also going to talk about recovering data in the FAT file system and
some of the limitations of data recovery.
Next slide.
Course 8, Module 1.
We're going to talk about an overview of the FAT file system and its history.
Next slide.
Let's start out by defining what a file system is.
A file system is a method of reading, writing, tracking,
and recovering data from a drive.
Your file system tracks the location of the data on your drive so
it knows where all your files, folders, and applications are.
So when we double click on a file or an application,
the file system knows where to go to retrieve that data.
It also tracks which clusters are in use, being occupied by a file.
And which clusters are available for
us to write a file to, or save an application to.
Next slide.
The history of the FAT file system.
When we started out with FAT12, which was 2 to the 12th power of bits,
that's how many bits we had to work with.
Which gave us 4,096 maximum clusters for the volume.
So we can only have 4,096 clusters on a FAT12 volume.
Now FAT16 which was 2 to the 16th power of bits to work with.
And this gave us 65,536 maximum clusters for the volume.
So it's better but
it's still not something you're going to see very often today.
Considering the size of drives,
these file systems really are not going to be applicable.
Next slide.
The next version of FAT we see in the evolution is FAT32.
Now FAT32 you will see today on removable media,
and it is possible to format a partition on
an internal drive on a Windows system FAT32.
FAT32 uses 28 bits not 32,
4 bits are reserved.
So it's 2 to the 28th power of bits that we have to work with.
Which gives us 268,435,456
maximum clusters that we can have on a FAT32 volume.
Now that's quite a bit more than we had with FAT16.
The latest version of FAT is ExFAT.
An ExFAT does use all 32 bits, so we have 32 bits to work with in ExFAT.
Which is 2 to the 32nd power.
And you can see the number on the slide of maximum clusters it is
quite a bit larger than FAT32.
And we are going to have a whole section on ExFAT throughout this path.
Next slide.
The FAT file system overview, well we have a system area and a data area.
Now in FAT12 and 16, the system area which comprised of
the volume boot records, FAT1 and 2, and the root directory.
And then we had our files and folders saved out in the data area.
Now because the root directory was in the system area on FAT12 and
16, the size was limited to one cluster.
So we only had one cluster to work with when we were addressing our files.
So that did cause some issues.
So we went to FAT32.
Now in FAT32, the volume boot record is in the system area and so is FAT1 and 2.
But the root directory in FAT32 was moved out to the data area to
allow the root directory to expand beyond that one cluster limitation,
allowing us to write a lot more files, folders, directories to our volumes.
In our next module, we're going to talk about the FAT volume boot record and
see the important information that is contained in that record.