1. Introduction to Computers
File Systems

2. Partitions and Volumes
A hard drive needs to be prepared properly in order to store data. The preparation takes three steps: You need to create a partition, organize the partition into a volume, and format the drive
A partition is a logical division of a hard drive disk. It is a portion of the hard drive prepared to save data on
It can be the size of the whole disk, or it can be a portion of the disk. This means that we can have one or more partitions on one hard drive
A volume is a logical storage space on the computer. It can be made of one or more partitions across one or more drives
When we create a volume it will be assigned a drive letter. This means that every drive letter doesn’t necessarily represent a physical drive, but rather a volume that can be made of one or more partitions and physical drives

3. Formatting The final step in preparing the drive is to format it
Formatting a disk removes all data from the disk (if it is not new) and sets the rules for how data will be stored on the drive
When formatting the disk you will be choosing the file system the drive will use and the cluster size for files
The cluster size is how large the building blocks for files are. For example, if we are using a 64k cluster size, and we store a 120k file then the drive will allocate 124k of the drive to the file
The file system is the rules for how to store files and directories on the disk as well as any features available for storage and management

4. Directories and Files
Directories (or folders) are logical objects that we can use to organize files and directories
We can think of them as containers that store the other folders and files
Directories take up very little disk space, since they are basically just a directory entry with their contents listed
Files are the actual data made by applications in the computer
They are one dimensional; they have a start and end point, and the data flows in one direction
Most file systems can store a single file in separate chunks to more efficiently use hard drive space. It is the file system’s job to describe where the file’s start and end, and how the chunks are linked to be able to take all of the chunks and reconstitute a single file from them

5. Device Manager and Hard Drives
We can look at our storage devices in device manager to examine them as hardware
One difference for hard drives is the volume tab, which must be populated before it shows us any information

6. Disk Management
You can’t fully manage your hard disks from the device manager, you need the disk management utility for that
We see here that our partitions are color coded blue for primary partitions, green for simple volumes, purple for spanned volumes and black for unallocated
Notice the difference between the simple volume on disk 1 and 2, and notice the spanned volume Art on both disk 1 and 2

7. NTFS vs FAT32
When we format a partition in order to prepare it for storing files we have to choose a file system
In Windows 10 NTFS (New Technology File System) will be selected by default, but we could also choose FAT32 (32 bit File Allocation Table)
NTFS allows us to implement user permissions on files and folder, create volumes and partitions up to 256 terabytes (FAT32 is limited to 2 terabytes), create files up to 16 terabytes (FAT32 is limited to 4 gigabytes), and store almost 20 times the number of files a FAT32 volume can
NTFS is almost always used for internal hard drives, whereas FAT32 (or the updated FAT64) is usually used in removable flash storage due to its lower overhead and reduced risk of corruption if the drive is not stopped before removing

8. Primary Partition
We have a limitation of 4 primary partitions per hard disk
This is a limitation of the MBR (Master Boot Record) partitioning, and as such is Operating System agnostic
The operating system used to have to be on the first primary partition, but now it can be located on any primary partition
There is a way to get around having only 4 partitions per disk

9. Extended Partition
An extended partition is not bootable, so we can’t place our operating system on the extended partition
We are also limited to one extended partition on a disk, and if we have an extended partition, then we can only have up to three primary partitions
Extended partitions are not directly formatted, instead we create logical partitions inside of them

10. Logical Partition
We can create up to 24 logical in a single extended partition, which is how we would break the 4 partition limit
Once a logical partition is made in the extended partition we can format it as if it were a primary partition
Other than not being bootable, the operating system will treat the logical partitions as if they were primary partitions

11. Active Partition
Each hard drive must have at least one active directory
An active directory is the partition that your bootloader looks to to load the operating system files from
You can have operating system files on any primary partition, but during startup the bootloader will only look at the active partition
Specifically, the bootloader will look at sector zero of the active partition for the boot application of the operating system
This is actually the final task of the BIOS, since after this the operating system will be in control

12. Basic Disk vs Dynamic Disk
Within Windows there are two types of distinct disk; basic disks and dynamic disks
Basic disks are compatible with all operating systems, but are limited to basic volumes
Basic volumes are unable to span across multiple disk
Dynamic disks allow for volumes spanning multiple disks, which also allows you to create a RAID array
Dynamic disks are only recognized in newer versions of Windows

13. GPT Partitioning
GPT (Global Unique Identifier Partition Table) is a newer format replacing MBR (Master Boot Record) Partitioning
Each partition created with GPT has a unique identifier number, different from every other GPT drive in the world
GPT offers a lot of features MBR does not -
Supports up to 128 partitions
Supports up to 9.4 zettabytes
Stores multiple copies of the partition table to help recover in case of corrupted data
Stores CRC (Cyclic Redundancy Check) values in order to check for corrupt data
Includes a protective MBR to let older tools see the drive as 1 large partition and not overwrite it as unallocated space
MBR will typically used for legacy systems, and GPT for newer. For example, if you need to boot into an older version of Windows, you may need MBR