Design and Plan for Storage Based Migrations, Technology Refresh (Hardware/os)

Storage Devices

What is a storage device?

Storage devices are the computer hardware used to call up/store data.

At that place are many types of storage devices, each with their own benefits and drawbacks.

Below are explanations about dissimilar storage devices.

Spring to a section on this folio:

Our Cloud Calculating page explains all nigh the benefits and drawbacks of using the cloud for storage or services.

Our Data Storage Capacity page explains all almost the diverse units of storage.

Hard Disk Drive (HDD)

What is a hard disk drive?

Hard deejay drives are non-volatile magnetic storage devices capable of remembering vast amounts of information.

An electromagnet in the read/write head charges the deejay's surface with either a positive or negative charge, this is how binary one or 0 is represented.

The read/write head is and then capable of detecting the magnetic charges left on the disk's surface, this is how data is read.

The disk surface is divided into concentric circles (tracks) and sectors (wedges). Dividing the surface in this way provides physical addresses to remember where data is saved.

A circuit lath carefully co-ordinates the rotating disk and swinging actuator arm to allow the read/write head to access any location very speedily.

Typical HDD capacities are measured in Terabytes (TB).

They tin be installed inside a estimator or purchased in a portable (external) format.

Typical applications for difficult deejay drives

Desktop computers
Laptop computers
Tv and satellite recorders
Servers and mainframes
Portable (external) drives are sometimes used to fill-in home computers or transfer large files

Benefits of hard disk drives

Capable of holding vast amounts of data at affordable prices
Fast read and write speeds
Reliable technology
Relatively modest in size

Drawbacks of hard disk drives

Due to the nature of its moving parts, they volition eventually wear and break
Although very fast, waiting for the moving parts ways it will never perform as fast equally solid state drives
More fragile and less robust than a solid state drive
Higher ability consumption than a SSD
Some racket is created by the moving parts

Solid State Bulldoze (SSD)

What is a solid state drive?

Solid state drives are non-volatile storage devices capable of holding large amounts of data.

They use NAND flash memories (millions of transistors wired in a series on a circuit board), giving them the reward of having no mechanical moving parts and therefore immediate admission to the data.

Solid state drives perform faster then traditional hd drives, still they are significantly more expensive.

This expense means that typical capacities are commonly measured in Gigabytes (GB).

They tin be installed inside a estimator or purchased in a portable (external) format.

Until we reach a betoken were big chapters SSDs are affordable, a compromise is to run two disk drives inside a reckoner. An SSD as the principal drive for your important programs and operating system, and a traditional HDD to store music, documents and pictures (which don't demand the faster admission times).

The lack of moving parts in an SSD makes information technology very robust and reliable, platonic for a portable device.

Typical applications for solid state drives

Smartphones
Tablet computers
Loftier-end laptops
Two drive desktop solutions
Portable drives are sometimes used in HD video cameras

Benefits of solid state drives

Extremely fast read/write speeds
Small in physical size and very light, ideal for portable devices
No moving parts to wearable, fail or get damaged – platonic for making portable computers and devices more than reliable and durable
Uses less power than a HDD, increasing battery life time
Very tranquillity
Generates less oestrus

Drawbacks of solid state drives

Expensive to buy (per GB)
Limited in capacity due to the expense
Express amount of writes

Random Access Retentiveness (RAM)

What is RAM?

RAM is a computer'south primary memory. Information technology is a very fast solid state storage medium that is directly accessible past the CPU.

Whatever open programs or files on a figurer are temporarily stored in RAM whilst beingness used.

Being volatile, any data stored in RAM will be lost when power is removed. This makes RAM totally unsuitable for the long term permanent storage of data – that is the role of a HDD or SSD instead.

Data is copied from secondary storage (HDD, SSD) to RAM every bit and when it is needed. This is because using a HDD as the primary retentivity would crusade a computer to perform much slower (a HDD or SSD is not directly accessible to the CPU, and isn't as fast as RAM).

RAM is a relatively expensive storage device and typical capacities are measured in Gigabytes (GB).

Computers operating with a capacity of RAM above the recommended minimum will benefit from better functioning and multitasking.

There are two types of RAM (SRAM and DRAM), each with their ain advantages and disadvantages.

Typical applications of RAM

The fast and directly accessible temporary (working) retentiveness needed by a computer

Benefits of RAM

Straight accessible to the CPU, making processing information faster
Fast solid state storage, making processing information faster

Drawbacks of RAM

Relatively expensive memory
Volatile – any data stored in RAM is lost when ability is removed

Static RAM (SRAM)

Information on SRAM does not crave refreshing.

However, the engineering is bulkier meaning less memory per chip.

More expensive than DRAM
Much faster than DRAM
Consumes less power
Commonly used in enshroud memory

Dynamic RAM (DRAM)

The nearly mutual blazon of RAM in use.

The data needs to be continually refreshed otherwise it fades away.

Continually refreshing the data takes time and reduces operation speeds.

Cheaper than SRAM
Ordinarily used in master memory

CD, DVD and Blu-Ray Discs

What are optical storage discs?

CD, DVD and Blu-Ray drives are optical storage devices.

Binary information is stored as changes to the texture of the disc'due south surface, sometimes thought of as microscopic pits and bumps.

These 'bumps' are located on a continuous spiral track, starting at the heart of the disc.

Whilst the disc is rotating at a constant speed, a laser is pointed at the spiral rail of 'bumps'.

The light amplification by stimulated emission of radiation will reflect/bounce off the disc surface in unlike directions depending upon whether a 1 or 0 has been read.

Disc capacities

In the pursuit of larger optical storage capacities, DVDs were created, followed by Blu-Ray.

CD	DVD	Blu-Ray
700 MB	4.7 GB	25 GB – 128 GB

Typical applications for optical media

CD – Audio and small amounts of data
DVD – Standard definition movies and information
Blu-Ray – HD video and big amounts of information

DVD

Despite being the aforementioned physical size, a DVD can hold more than information than a CD.

To achieve this, a more tightly packed spiral track is used to store the data on the disc.

To accurately access the smaller 'bumps', a effectively red light amplification by stimulated emission of radiation is used in a DVD drive than that found in a standard CD drive.

To increase capacity further, DVDs are likewise capable of dual layering.

Blu-Ray

Blu-Ray engineering science squashes even more data into the aforementioned size disc as a CD or DVD.

The spiral data tracks on a Blu-Ray disc are so small a special bluish (violet) laser has to be used to read the 'bumps'.

Like a DVD, Blu-Ray discs are capable of storing information on multiple layers.

Recordable Optical Media

CD-ROM, DVD-ROM, Blu-Ray-ROM

Read just – the data is permanently written to the disc at the point of manufacture.

CD-R, DVD-R, BD-R

Recordable – blank discs that tin can exist burnt (written to) once.

CD-RW, DVD-RW, BD-RE

Re-writable – blank discs that tin can be burnt (written to) over and over once again (tin can be erased and reused many times).

DVD-RAM

What is DVD-RAM?

DVD-RAM is an optical media storage device.

It differs from a traditional DVD in that information is stored in concentric tracks (like a HDD) which allows read and write operations to be carried out at the same time.

This ways, for example, that when used in a personal video recorder y'all can tape 1 television programme whilst watching a recording of another. This allows handy features such every bit 'time slip' to be possible.

When used inside a CCTV system yous could review footage whilst still recording your cameras.

The chapters of DVD-RAM is 4.7 GB, or nine.4 GB for double-sided discs.

Typical applications for DVD-RAM

Personal and digital video recorders
High-end CCTV

Benefits of DVD-RAM

Read and write at the aforementioned time
Can be rewritten to many more than times than a traditional DVD-RW
Has write-protect tabs to prevent adventitious deletion when used in an optional cartridge
Data is retained for an estimated xxx years. This long life is great for archiving data
Reliable writing of discs because the verification done past the hardware, not by software

Drawbacks of DVD-RAM

Disc speeds higher than 5x are less common
Less compatibility than DVD-RW

ROM

What is ROM?

ROM is a non-volatile retentivity flake whose contents cannot be contradistinct.

It is frequently used to store the start up routines in a computer (e.g. the BIOS).

Typical applications for ROM

Storing the computer's start up routine

USB Wink Retention

What is USB Flash Memory?

Flash are not-volatile solid land storage devices which utilize NAND wink memories to store data (millions of transistors).

USB refers to the USB connection that allows users to plug the device into the USB port of a computer.

Other types of flash storage include the memory cards used in digital cameras.

Wink memory comes in a variety of capacities to accommodate most budgets and requirements.

Typical applications for flash memory

USB retentivity sticks – saving and transferring documents etc
Retentiveness cards in digital cameras

Benefits of flash memory

Portable, modest and lightweight
Durability, wink has no moving parts to damage
Range of capacities available
Fast speeds, with no moving parts of kick up time

Drawbacks of flash memory

Express (merely huge) number of write cycles possible
Actually high capacities are uncommon
In relative terms, an expensive storage choice compared to a HDD

Our Deject Computing folio explains all about the benefits and drawbacks of using the cloud for storage or services.