Types of Storage Devices in Network

2. WHAT IS STORAGE?
• STORAGE IS THE GROUP OF TECHNIQUES AND TOOLS THAT CAN RECORD ANDPRESERVE DIGITAL DATA ON
MEDIA.
• TYPICALLY, STORAGE IS REFERRED TO AS THE DATA STORAGE DEVICES THAT ARE ATTACHED TO THE
COMPUTER VIA INPUT OR OUTPUT ACTIVITIES.
• THESE DEVICES INCLUDE HARD DRIVES, FLASH MEMORY, SAN, NAS, LEGACY TAPE SYSTEMS, AND OTHER
FORMS OF MEDIUM.

3. DAS (DIRECTLY ATTACHED STORAGE)
• THIS DIRECTLY ATTACHED STORAGE (DAS) DEVICE IS AS EASY TO USE ASIT SOUNDS.
• AN EXTERNAL HARD DRIVE ATTACHED VIA A UNIVERSAL SERIAL BUS (USB) CONNECTOR SERVES AS A STRAIGHTFORWARD
ILLUSTRATION OF DAS.
• WHEN WE TALK ABOUT STORAGE, WE MEAN A NUMBER OF DRIVES OR AN ARRAY OF DISCS THAT WORK IN CONCERT.
• WHETHER THERE ARE ONE DRIVE OR 24 DRIVES, THE DAS IDEA IS THE SAME. SIMILARLY, EVEN IF WE USE A DIFFERENT WIRE,
THE IDEA REMAINS THE SAME. IN GENERAL, USB IS CONSIDERABLY SLOWER FOR LARGE DAS UNITS. FOR A SMALL-TO-
MEDIUM SIZED FIRM, WHERE SUFFICIENT STORAGE CAN BE BUILT AT A MINIMAL INITIAL COST, DAS IS A GOOD FIT.
• THE ADDITIONAL DISC DRIVES CAN BE HOUSED INSIDE A SEPARATE CABINET THAT SERVES AS THE DAS ENCLOSURE. A PCI-
BASED INTERNAL RAID CONTROLLER

6. NAS (NETWORK ATTACHED STORAGE)
• ANY COMPUTER THAT SERVES AS A FILE SERVER ON A NETWORK, REGARDLESS OF THE NUMBER OF DISCS OR THE AMOUNT
OF STORAGE SPACE IT HAS, CAN BE REFERRED TO AS A NAS.
• A NETWORK ATTACHED STORAGE (NAS) DEVICE IS MERELY A COMPUTER THAT SHARES FILES ACROSS A NETWORK, TO PUT
IT ANOTHER WAY.
• THEORETICALLY, IT IS NEARLY EQUIVALENT TO AN EXTERNAL USB HARD DRIVE, WITH THE EXCEPTION THAT A NAS CONNECTS
VIA ETHERNET OR ANOTHER NETWORKING WIRE RATHER THAN A USB CABLE.A SHARED RESOURCE IS AVAILABLE ON NAS
DEVICES.
• THAT RESOURCE IS USABLE BY NUMEROUS MACHINES AND PEOPLE. SINCE THE DISC ARRAYS IN NAS AND DAS PERFORM
AND OPERATE SIMILARLY, YOU MAY DESIGN COMPARABLE RAIDS AND PARTITION STYLES ON BOTH.
• NAS WORKS WELL FOR SMBS.

7. NAS (NETWORK ATTACHED STORAGE)

8. SAN (STORAGE AREA NETWORK)
• ANY COMPUTER THAT SERVES AS A FILE SERVER ON A NETWORK, REGARDLESS OF THE NUMBER OF DISCS OR THE AMOUNT
OF STORAGE SPACE IT HAS, CAN BE REFERRED TO AS A NAS.
• A NETWORK ATTACHED STORAGE (NAS) DEVICE IS MERELY A COMPUTER THAT SHARES FILES ACROSS A NETWORK, TO PUT
IT ANOTHER WAY.
• THEORETICALLY, IT IS NEARLY EQUIVALENT TO AN EXTERNAL USB HARD DRIVE, WITH THE EXCEPTION THAT A NAS CONNECTS
VIA ETHERNET OR ANOTHER NETWORKING WIRE RATHER THAN A USB CABLE.
• A SHARED RESOURCE IS AVAILABLE ON NAS DEVICES. THAT RESOURCE ISUSABLE BY NUMEROUS MACHINES AND PEOPLE.
SINCE THE DISC ARRAYS IN NAS AND DAS PERFORM AND OPERATE SIMILARLY, YOU MAY DESIGN COMPARABLE RAIDS AND
PARTITION STYLES ON BOTH.
• NAS WORKS WELL FOR SMBS.

9. SAN (STORAGE AREA NETWORK)

10. CONTENT ADDRESSED STORAGE (CAS)
• AN OBJECT-BASED SYSTEM CALLED CONTENT ADDRESSED STORAGE, OR CAS, IS DESIGNED FOR STORING AND MANAGING
FIXED CONTENT DATA. IT IS MADE FOR THE SAFE ONLINE ARCHIVING ANDRETRIEVAL OF FIXED MATERIAL.
• INSTEAD OF USING FILE NAMES AND THE PHYSICAL LOCATION OF DATA FOR STORAGE AND RECOVERY LIKE FILE-LEVEL AND
BLOCK-LEVEL DATA ACCESS, CONTENT ADDRESSED STORAGE SAVES USER DATA AND ASSOCIATED INFORMATION AS
INDEPENDENT OBJECTS. A CONTENT ADDRESS (CA), ALSO KNOWN AS A GLOBALLY UNIQUE ADDRESS (GUIA), IS GIVEN TO THE
STORED OBJECT.
• ELECTRONIC RECORDS LIKE CONTRACTS, CLAIMS, EMAIL ATTACHMENTS, DIGITAL RECORDS LIKE PHOTOS, CHECKS, ETC.,
AND RICH MEDIA RECORDS LIKE X-RAY, CT SCAN, VOICE MAIL, RADIO, ETC. ARE EXAMPLES OF FIXED CONTENT DATA.

11. CONTENT ADDRESSED STORAGE (CAS)