Hard Disk Drive

1. Presented By
Roll No. Name
2301 Ajinkya Patil
2306 Kiran Malgavi
2307 Akash Kote
2313 Swapnil Gadade
2321 Rohan Awale

2. Sr. No Title Page No.
1 INTRODUCTION
2 History
3 Two Major Aspects of Information Security
4 Defense In Depth
5 Security classification for information
6 EXAMPLES
7 Security Chart
8 Conclusion
9 References
10
11
12

3. Hard Disk Drive
• A hard disk drive is a
sealed unit that a PC uses
for nonvolatile data
storage.
• A hard disk drive contains
rigid, disk-shaped
platters, usually
constructed of aluminum
or glass

4. Logic Boards
• All hard disk drives have one or more logic boards mounted on them.
• The logic boards contain the electronics that control the drive's
spindle and head actuator systems and present data to the controller
in some agreed-upon form.
• On ATA drives, the boards include the controller itself, whereas SCSI
drives include the controller and the SCSI bus adapter circuit.

5. • Sectors Tracks:-Data is stored
on the surface of a platter in
sectors and tracks.
• Heads:-One side of a platter is
called a “head”.

6. Computer Data Storage
• The read/write head on the drive moves very close to the spinning
disk as it goes by and writes to specific concentric rings on the disk,
called tracks.
• storage involves three steps:
• Low-Level formatting (LLF)
• Partitioning
• High-level formatting (HLF)

7. Low Level Formatting
•Low-level format- organizes both
sides of each platter into tracks and
sectors to define where items will be
stored on the disk.
• A sector is a small section of a track
that stores 512 Bytes of information
Track
Sector

8. Partitioning
• Partitioning: divide hard disk into separate
areas called partitions; each partition functions
as if it were a separate hard disk drive.
• Partitioning is required because a hard disk is
designed to be used with more than one
operating system.
• Partitioning enables a single hard disk drive to
run more than one type of operating system
(dual boot), or it can enable a single operating
system to use the disk as several volumes or
logical drives.

9. High Level Formatting
• High-level format: defines the file allocation
table (FAT) for each partition, which is a table of
information used to locate files on the disk.
• If the disk is to be made bootable,
COMMAND.COM and two system files (io.sys and
msdos.sys) must be in the root directory of the
bootable drive.

10. Platters
• A hard disk drive has one or more platters, or disks.
• Most hard disk drives have two or more platters, the number of platters a
drive can have is limited by the drive's vertical physical size.
• Platters have traditionally been made from an aluminum/magnesium alloy,
which provides both strength and light weight. However, manufacturers'
desire for higher and higher densities and smaller drives has led to the use
of platters made of glass.
•

11. Recording Media
• No matter which substrate is used, the platters are covered with a thin
layer of a magnetically retentive substance, called the medium, on which
magnetic information is stored.
• Two popular types of magnetic media are used on hard disk platters:
-Oxide medium
-Thin-film medium

12. Drive Operation: magnetization
• HDDs record data by magnetizing ferromagnetic material directionally,
to represent either a 0 or a 1 binary digit.
• The Co-based alloy thin films are polycrystalline and the size of grains
has an order of 10 nm.
• In practice, a group of grains (about 100) are magnetized as one bit.

13. Read Write Heads
• A hard disk drive usually has one read/write head for each platter
surface These heads are connected, or ganged, on a single movement
mechanism.

14. Air Filters
• Nearly all hard disk drives have
two air filters.
• One filter is called the
recirculating filter, and the other
is called either a barometric or
breather filter.
• These filters are permanently
sealed inside the drive and are
designed never to be changed for
the life of the drive.

15. Spindle Motors
• The motor that spins the platters is called the spindle motor.

16. Cables and Connectors
• Hard disk drives typically have several connectors for
interfacing to the computer, receiving power, and
sometimes grounding to the system chassis.
• Most drives have at least these three types of connectors:
-Interface connector(s)
-Power connector
-Optional ground connector (tab)
10/19/2016 16

17. IDE Hard Drive
• Originally hard drives required a separate plug-in controller to
connect the drive to the rest of the system.

18. Tracks and sectors
Track=
concentric
circle
Sector =
small arc
of track
Can store
512 bytes

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