Physical environments 4- Data storage and recovery (RAID, NAS , SAN)

Question 1

What is redundant array of independent disks (RAID)?

Answer 1

RAID is a tech that combines multiple physical disk drives into a single logical unit to improve data storage and recovery

RAID offers redundancy and fault tolerance, which means that if one disk fails, the data can still be accessed and retrieved from the other disks

Question 2

How does RAID 1 work?

Answer 2

Two identical disks are used, and all the data is written to both disks simultaneously.
This means that if one disk fails, the data is still accessible on the other disk

Question 3

What is RAID 1 also known as?

Answer 3

RAID 1 is also known as mirroring

Question 4

Benefit of RAID 1?

Answer 4

RAID 1 offers excellent data redundancy due to mirroring all data onto a second disk.

Question 5

Drawback of RAID 1?

Answer 5

you are essentially cutting storage capacity in half as everything is duplicated

Question 6

How does RAID 5 work?

Answer 6

RAID 5 uses 3 or more disks and provides both data striping and parity
Data striping is a technique where data is split into small chunks and stored across multiple disks in a way that improves read and write performance.

Parity is additional information that is used to provide redundancy. If one disk fails, the data can be rebuilt using the parity information.

Question 7

Benefit of RAID 5?

Answer 7

RAID 5 offers very good performance benefits and fault tolerance

Question 8

Drawback of RAID 5?

Answer 8

requires 3 disks, which is expensive and can only stand one disk drive failure.

Question 9

How does RAID 10 work?

Answer 9

RAID 10 is a combination of RAID 1 and RAID 0.

It requires at least four disks, and it provides both mirroring and striping. Data is mirrored across two disks, and the mirrored pairs are then striped across the remaining disks

Question 10

Benefit of RAID 10?

Answer 10

RAID 10 offers excellent fault tolerance, performance and recovery speed

Question 11

Drawback of RAID 10?

Answer 11

it’s expensive since it requires at least four disks.

Question 12

NAS- Network attached storage

What is NAS?

Answer 12

*It is a type of storage device that connects to a network and provides file-level data access to multiple clients.
*File level access is when a user can access individual files and folders on a computer system, allowing them to read, write, execute, and modify the contents of the file

*NAS devices are standalone devices and provides a centralized storage space for multiple devices to access and share files

Question 13

What does NAS use to operate and where is it commonly used?

Answer 13

It operates using a standard network connection, such as Ethernet, and is often used in home or small business networks.

Question 14

Explain NAS in simple terms

Answer 14

NAS system is like a shared hard drive that can be accessed by all devices on the network, such as computers, smartphones etc…

Question 15

Give advantages of NAS

Answer 15

*Are simple to install and manage
*Are often more cost-effective than SAN systems
*Can be easily expanded with additional hard drives
*Enables simple data sharing between multiple users on the same network

Question 16

Give disadvantages of NAS

Answer 16

*May not provide the high-speed performance needed for data-intensive applications

single point of failure

*May have limitations in terms of the number of users or storage capacity they can support

Question 17

Explain SAN - Storage Area Network

What is block level access?

Answer 17

*a type of network that provides block-level data access to multiple clients.
*Block level access is when a user has direct access to computer memory at the block level, allowing users to view, edit, and modify data stored in memory blocks on the computer. It also allows them to move data around in blocks rather than solely within individual files or folders.

Question 18

Where are SAN systems usually used?

Answer 18

SAN systems are often used in larger enterprise networks where high performance and reliability are critical.

Question 19

What does a SAN network consist of, in terms of physical devices?

Answer 19

A SAN system consists of one or more dedicated storage devices connected to one or more servers via a specialized high-speed network. Unlike NAS, SAN systems use their own network connection and protocols for communication

Question 20

Advantages of SAN

Answer 20

*Provides high-speed access to shared data storage because all the devices are connected to each other
is fault tolerant
*Can be easily scaled up to support large enterprise networks
*Allows for centralised management and monitoring of storage resources

Question 21

Disadvantages of SAN

Answer 21

*Often more expensive than NAS systems
*Require specialized knowledge and skills to set up and manage
*May not be as flexible as NAS systems in terms of storage capacity

Question 22

where is NAS usually used?

Answer 22

in homes and small-medium sized businesses.