User manual

INTRODUCTION

utilities are not affected, regardless of the RAID level selected. Cor-

rect installation of the disk array and the controller requires a proper

understanding of RAID technology and the concepts.

1.5.1 RAID 0

RAID 0, also referred to as striping, writes stripping of data across

multiple disk drives instead of just one disk drive. RAID 0 does not

provide any data redundancy, but does offer the best high-speed

data throughput. RAID 0 breaks up data into smaller blocks and

then writes a block to each drive in the array. Disk striping en-

hances performance because multiple drives are accessed simul-

taneously; but the reliability of RAID Level 0 is less than any of its

member disk drives due to its lack of redundancy.

1.5.2 RAID 1

RAID 1 also known as “disk mirroring”, data written to one disk drive

is simultaneously written to another disk drive. Read performance

may be enhanced if the array controller can parallel accesses both

members of a mirrored pair. During writes, there will be a minor

performance penalty when compared to writing to a single disk. If

one drive fails, all data (and software applications) are preserved

on the other drive. RAID 1 offers extremely high data reliability, but

at the cost of doubling the required data storage capacity.