Another advantage of a RAID level 0 configuration is that it utilizes the full capacities of the drives. If you have two 120-GB drives installed, you have 240 GB

on which to store data.

NOTICE:

Because RAID level 0 provides no data redundancy, if one drive fails, then the data on the other drive is also inaccessible. Therefore, ensure

that you perform regular backups when you use a RAID level 0 configuration.

RAID Level 1

RAID level 1 uses a data-redundancy storage technique known as "mirroring." When data is written to the primary drive, the data is then duplicated—or

mirrored—on the other drive. A RAID level 1 configuration sacrifices high-data access rates for its data redundancy advantages.

If a drive failure occurs, subsequent read and write operations are directed to the surviving drive. A replacement drive can then be rebuilt using the data from

the surviving drive. Also, because data is duplicated on both drives, two 120-GB RAID level 1 drives collectively have a maximum of 120-GB on which to store

data.

RAID Level 5

RAID level 5 uses a data-staging storage technique known as "data parity." When data is written to the primary drive, it is then duplicated on at least three

other drives. As opposed to a RAID level 1 setup which writes to one other volume that acts as a data mirror, a RAID level 5 configuration writes data to each

drive in increments which places data from each segment across multiple drives. A RAID level 5 configuration has higher data-access rates but requires more

storage space than a RAID level 0 or RAID level 1 configuration.

If a drive failure occurs, subsequent read and write operations are directed to the other surviving drives. A replacement drive can then be rebuilt using the

data from the surviving drives. Also, because data is duplicated on the primary and additional drives, four 120-GB RAID level 1 drives collectively have a

maximum of 360-GB on which to store data.

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