RAID 3

Reading: [reidosuri]
Full spelling: Redundant Arrays of Inexpensive Disks 3
Field:
Storage > hard disk > RAID 3

One of the level of RAID. The system where it allots to the record of the error correcting code which is called the inside 1 units of disk which is plural parity disperses the data to the other disk and records. Whichever 1 units breaking down, exchanging, it is possible to restore the data. In addition, dispersing the data to the other disk, simultaneous in parallel, in order to record, also acceleration is measured.

RAID 4

Reading: [reidohuo]
Full spelling: Redundant Arrays of Inexpensive Disks 4
Field:
Storage > hard disk > RAID 4

One of the level of RAID. The system where it allots to the record of the error correcting code which is called the inside 1 units of disk which is plural parity disperses the data to the other disk and records. As for the difference with RAID 3, dispersion of the data is not the bit unit and the point which is done at the block unit.

RAID 5

Reading: [reidohuaibu]
Full spelling: Redundant Arrays of Inexpensive Disks 5
Field:
Storage > hard disk > RAID 5

RAID 6

Reading: [reidoshitsukusu]
Full spelling: Redundant Arrays of Inexpensive Disks 6
Field:
Storage > hard disk > RAID 6

Dispersing the data to the many hard disk, one of level of the RAID technology which raises resistance obstacle characteristic by writing in parallel. The system where it forms 2 error correcting codes which are called parity the occasion where one data block is written with the data disperses and writes.

Because with RAID-5 parity is one, when 2 units break down simultaneously, it becomes impossible but, with RAID-6 to restore the data, two taking the parity which differs in order to record both, 2 units breaking down simultaneously, the data can be restored. However, the memory capacity which it cuts because of parity reaches 2 times that RAID-5, when recording also time for parity formation is required excessively and entry speed decreases. Extremely, if among brief it does not break down in consecution, (the probability where that kind of phenomenon occurs has not spread because quite it is low) it can correspond with the combination of RAID-5 and hot spare, excessively.

RAM

Reading: Ram
Full spelling: Random Access Memory
Field:
Semiconductor > memory > RAM > RAM

The storage unit which utilizes the semiconductor device. In main memory (processor storage) of the computer it is utilized. There are also times when thing of main memory is called RAM.

In order to do the reading and writing of the data electrically, at high speed, from CPU (central processing unit) it can access operation directly, but because price per unit capacity is high, you cannot use RAM in large quantities. In addition, when power is turned off, there is a fault that contents are lost.

Because of this, other than RAM, external memory unit such as hard disk and floppy disk (auxiliary memory) to be equipped in the computer, the user starting the program and the case where processing the data is done just those which are necessary calling to RAM, you use, the external memory unit is utilized in long-term retention.