The relationship between iot and communication technology
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
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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.
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)
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17. IDE Hard Drive
• Originally hard drives required a separate plug-in controller to
connect the drive to the rest of the system.