What’s RAID?


You may have heard “RAID”, but what’s this? I’ll explain about RAID today.


RAID is the abbreviation of “Redundant Array of Inexpensive Disks”, and technology to make some HDDs recognize as one drive.

Thanks for this technology, computer can improve redundancy in case of failure, and speed up data storage by writing data on some HDDs.

Types of RAID

Although there are some types of RAID, RAID0,1,5,6 are used often, so I’ll explain about these.


RAID0 is simple.

Data is written on some HDDs without duplicating, so computer can utilize the full capacity of HDDS. However, since there is no redundancy, computer cannot improve the security.


On RAID1 which is called “mirroring”, data is duplicated and written on two HDDs. The merit is that when one of HDDs broke, full data remain. On the other hand, there is demerit doubling the size because of duplicating the data.


On RAID5, computer save the data called “Parity”. Thanks for this Parity, when one of HDD broke, the data would be recovered. However computer have to calculate the Parity and be overloaded.


RAID6 is similar to RAID5. On RAID6, computer duplicate the Parity in duplicate which improve durability. Although computer can’t recover full data when 2 HDD break on RAID5, computer can recover full data in such situation on RAID6.


Copied title and URL