NetworkAttached Storage Networkattached storage devices Attached to a

Network-Attached Storage

Network-attached storage devices • Attached to a local area network, generally an Ethernet-based network environment

Network-attached storage devices • Assigned their own IP address 192. 168. 221. 50

Network-attached storage devices • Allow for multiple computers to access data

Network-attached storage devices • Able to comprise of single or multiple disks and can utilize technologies such as RAID

Network-attached storage devices Comprises of • hard disk storage – can include multi-disk and/or RAID systems • software for configuring and file locations mapping to the network-attached device +

Redundant Array of Independent Disks • also known as RAID • a way of combining the storage capabilities of more than one hard disk for enhanced purposes, including: – an increase in performance – fault tolerance. • Several different configurations of RAID – Most Common include RAID 0, RAID 1, and RAID 5

RAID 0 • also referred to as disk striping • data is written across multiple drives simultaneously

RAID 0 Benefits – speeds up the traditional transfer speed of data Disadvantages • provides no fault tolerance – Should a single drive in a RAID 0 array fail, all content is lost as content is distributed in bits across multiple drives.

RAID 1 • also referred to as disk mirroring • creates an exact duplicate of data written two separate disks

RAID 1 Benefits • Provides fault tolerance – In the event of a disk failure, RAID 1 allows for the quickest and easiest method of data retrieval by switching to the backup or alternative drive. Disadvantages • is costly because all storage needs are doubled to account for the space redundancy, and there is no increase in data access

RAID 5 combines the benefits of both RAID 0 and RAID 1 – speeds up the traditional transfer speed of data – Provides fault tolerance

RAID 5 • uses a parity block interleaved across all the disks in the array, in addition to striping the data across the same drives.

Parity • is done by storing an extra bit with and based on each byte in memory. • When a byte is accessed, the validity of the parity bit is checked.

RAID continued • The higher number does not signify a later or better implementation of RAID 30 > RAID 10

RAID continued • However, certain number may signify the implementation of two RAID structure such as RAID 10 or RAID 01, which are combinations of RAID 1 and RAID 0.

Images borrowed from: • • • http: //www. hdd-tool. com/raid-0 -features-advantage-and-disadvantage. htm http: //www. raids. co. uk/raid_0+1. htm http: //networkingpupil. blogspot. com/2010/10/nas_03. html http: //hothardware. com/Reviews/Thecus-N 7700 -Network-Attached-Storage. Server/ http: //www. nasreview. org/d-link-2 -bay-network-attached-storage-enclosure-dns 323/1 http: //benchmarkreviews. com/index. php? option=com_content&task=view&id=58 &Itemid=70