Gateway P-6831, Reference Manual

Page: 61 / 168

www.gateway.com
53
How it makes file storage cheaper
Because RAID 0 lets your notebook see multiple hard drives as
a single drive, you can install two lower capacity (less
expensive) drives and have the same single-drive storage
simplicity and capacity as a larger, more expensive hard drive.
Drawbacks
Unfortunately, RAID 0 lets two drives behave as one in another
way. If part of the array fails (such as a hard drive crashing),
the entire array fails. Because the drives are treated like a single
drive, parts of files (including operating system files) can be
spread across both drives, leaving the notebook with only file
fragments if one drive fails. Regular and frequent backups are
critical.
Another drawback is that RAID 0 treats each hard drive as if it
has the storage capacity of the smallest drive in the array. So
if you have two drives (300 GB and 200 GB) in a RAID 0 array,
your notebook only recognizes 400 GB total capacity.
RAID 1 for security
RAID 1 maintains a complete copy of all files on each physical
hard drive in the array. Maintaining simultaneous, complete
copies of files across both hard drives is called
mirroring . If a
drive fails, the mirrored drive takes over and acts as the
primary drive.
In the graphic below, each letter represents a unique block of
data, and each column represents a separate hard drive.
File reading performance ( seek time ) is increased using the
same methods that RAID 0 uses, although writing speed is the
same as if writing to a single hard drive.
A
B
C A
B
C
RAID 1