Module 6 RAID and Expansion Devices

RAID

(Redundant Array of Independent disk) A disk subsystem that increases performance or provides fault tolerance or both.It is a way of storing the same data in different places on multiple hard disks to protect data in the case of a drive failure.

RAID 0+1 Advantages

the implementation has the benefits of RAID 0 speed and RAID 1 safety. It is also much easier to implement than RAID 3, RAID 5 or RAID 6.

RAID 0 Recommended Applications

1. Video Production and Editing 2. Image Editing 3. Pre-Press Applications 4. Any application requiring high bandwidth

RAID 10 Advantages

Combining these two storage levels makes RAID 10 fast and resilient at the same time. If you need hardware-level protection for your data and faster storage performance, RAID 10 is a simple, relatively inexpensive fix.

RAID 1 advantages

It is possible to combine the advantages (and disadvantages) of RAID 0 and RAID 1 in one single system. This is a nested or hybrid RAID configuration. It provides security by mirroring all data on secondary drives while using striping across each set of drives to speed up data transfers

RAID 5 Disadvantages

Lack of performance and data has to be written twice, taking a longer time.

RAID 10 Disadvantages

Lower usable capacity/High cost. Limited scalability

RAID Levels

RAID 0 (Disk striping): RAID 0 splits data across any number of disks allowing higher data throughput. ... RAID 1 (Disk Mirroring): ... RAID 5 (Striping with parity): ... RAID 6 (Striping with double parity): ... RAID 10 (Striping + Mirroring)

Why RAID

RAID is a technology that is used to increase the performance and/or reliability of data storage A RAID system consists of two or more drives working in parallel.

Software vs Hardware

Software= programs in the computers and uses the computer processor, memory, and hard drive to create and save documents Hardware=the physical parts of a computer

Network Devices

are components used to connect computers or other electronic devices together so that they can share files or resources like printers or fax machines. Devices used to setup a Local Area Network (LAN) are the most common type of network devices used by the public. A LAN requires a hub, switch, router

RAID Controllers

is a hardware device or software program used to manage hard disk drives (HDDs) or solid-state drives (SSDs) in a computer or storage array so they work as a logical unit.

RAID 1 Recommended Applications

1. Accounting 2. Payroll 3. Financial 4. Any application requiring very high availability

RAID 5 Recommended Applications

1. File and Application servers 2. Database servers 3. WWW, E-mail, and News servers 4. Intranet servers 5. Most versatile RAID level

Audio/Video Devices

An input device is any device that sends data from an outside source into a processing system such as a computer or television. ... There are several types of video input devices that allow you to play video from an external device on a video display.

RAID 10 Recommended Applications

Database server

RAID 5 Advantages

If you've every suffered a hard drive failure, you'll know how it feels to lose data. ... RAID is an acronym that stands for Redundant Array of Independent Disks, and as this suggests, combines multiple hard-drives that work together, so that if one hard-drive goes down, your data storage does not.

RAID 0+1

Imaging applications General fileserver

RAID 0+1: High Data Transfer Performance

RAID 0+1 means arrays implemented as RAID 1, whose elements are RAID 0 arrays.

RAID 0+1 Disadvantages

The main drawback of such a solution is its cost

Scanners

a device that scans documents and converts them into digital data.

RAID 10 (Very High Reliability combined with High Performance)

also known as RAID 1+0, is a RAID configuration that combines disk mirroring and disk striping to protect data. It requires a minimum of four disks, and stripes data across mirrored pairs. As long as one disk in each mirrored pair is functional, data can be retrieved.

RAID 5: Independent Data disks with distributed parity blocks

is a redundant array of independent disks configuration that uses disk striping with parity. Because data and parity are striped evenly across all of the disks, no single disk is a bottleneck. Striping also allows users to reconstruct data in case of a disk failure.

Biometric Devices

is a security identification and authentication device. Such devices use automated methods of verifying or recognising the identity of a living person based on a physiological or behavioral characteristic. These characteristics include fingerprints, facial images, iris and voice recognition.

RAID 1 disadvantages

is that the effective storage capacity is only half of the total drive capacity because all data get written twice. Software RAID 1 solutions do not always allow a hot swap of a failed drive.

RAID 1

is the replication of data to two or more disks. Disk mirroring is a good choice for applications that require high performance and high availability, such as transactional applications, email and operating systems.

RAID 0: Striped Disk Array without Fault Tolerance

provides no fault tolerance or redundancy, the failure of one drive will cause the entire array to fail; as a result of having data striped across all disks, the failure will result in total data loss. This configuration is typically implemented having speed as the intended goal