SurfRAID LC16 Series User’s
Manual
7
CHAPTER 1.
INTRODUCTION
RAID CONCEPTS
The need to ensure continuous access to critical computer data is essential today in such a highly
competitive business environment. Data loss and server downtime caused by drive failure often
results in lost productivity, decreased profitability, and can differentiate between success and
failure in a competitive business environment. RAID (Redundant Array of Independent Drives)
addresses this problem. The Benefits of RAID include:
Availability
Provides fault-tolerance by mirroring or parity operation. If any single disk drive in the RAID
fails, the RAID still continues to function without loss of data.
Capacity
Provides disk spanning by weaving all connected drives into one single volume.
Performance
Increases disk access speed by breaking data into several blocks when reading / writing to several
drives in parallel. With RAID, storage speed increases as more drives are added.
1.1.1 RAID LEVELS
The
SurfRAID
LC16 supports RAID Levels 0, 1, 3, 5 & 0+1. Each RAID level offers a different
performance, functionality and fault tolerance, depending on the application that will be used.
The following is a brief explanation of each RAID level. Before configuring the
SurfRAID
LC16, be
sure to know which RAID level is best suited for your application.
1.1.1.1 Striping (RAID 0)
Striping refers to the storing of data across multiple drives in a drive group. If there are three
drives in a drive group then the subsequent data will be stored across all three drives. This cre-
ates a very high performance virtual disk with the capacity equal to the combined capacity of the
installed disks. RAID Level 0 provides high availability and very high performances for both
read and write operations. However, no redundant parity is generated for protection against disk
failure.
Block1
Block2
Block3
Block4
Block5
Block6
Block7
Block8
Block1
Block2
Block3
Block4
Block5
Block6
Block7
Block8
Striping
Data
Disk 1
Disk 2
RAID 0
