Storage System Environment

 Understand Storage System

• Group of components providing storage facilities to one or numerous computer

Components of Storage System Environment 

• Host
• Connectivity
• Storage

Components of Host 

• Physical Components :- 

• Logical Components :-

The components of connectivity in a storage system environment can be classified as physical and logical. The physical components are the hardware elements that connect the host to storage and the logical components of connectivity are the protocols used for communication between the host and storage.

Components of Storage Devices 

A storage device uses 3 types of media :-

• Magnetic Media
• Optical Media
• Solid State Media

Understanding your Disk Drive

• Randomly accessible
• Rewriteable storage media
• Store and retrieves information
• Can be Internal or External
• Offers large storage capacity

Components of Hard Drive :-

The hard drive, which typically provides storage for data and applications within a computer, has four key components inside its casing -- the platter (for storing data), the spindle (for spinning the platters), the read/write arm (for reading and writing data) and the actuator (for controlling the actions of the read/write arm). Only the most technically proficient IT professionals should attempt to work on the components inside a hard drive.

Platters

• Flat, circular disk like structure stacked on each other
• Rotates at Multiple RPM
• Supports storage and read/write on both top and bottom surfaces
• Data is stored as 0 and 1 in sectors, tracks, and cylinder

Platters are made out of aluminum, glass or ceramic and have a magnetic surface in order to permanently store data. 

The Spindle

• Rotating shaft in middle of disk drive 
• Holds together rotating platters
• Rotates at several thousand of RPM
• Spindle speed can be 7200 RPM, 10000 RPM, 15000 RPM
• Spindle speed affect seek time

The spindle keeps the platters in position and rotates them as required. The revolutions-per-minute rating determines how fast data can be written to and read from the hard drive. A typical internal desktop drive runs at 7,200 RPM, though faster and slower speeds are available. The spindle keeps the platters at a fixed distance apart from each other to enable the read/write arm to gain access.

Read/Write Head

• Reads and Write data to from the platter
• Two read/write heads per platter

Landing Zone: Resting zone of read/write head

Head Crash: Accidently landing of read/write head on platter other than on landing zone

Actuator

The actuator or head actuator is a small motor that takes instructions from the drive's circuit board to control the movement of the read/write arm and supervise the transfer of data to and from the platters. It's responsible for ensuring the read/write heads are in exactly the right place at all times.

Other Components

As well as the casing on the outside of the hard disk that holds all of the components together, the front-end circuit board controls input and output signals in tandem with the ports at the end of the drive. No matter what the type of drive, it has one port for a power supply and one port for transferring data and instructions to and from the rest of the system.