Areca ARC-1231ML/1261ML/1280ML Computer Hardware User Manual


 
INTRODUCTION
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1.6.2 RECOVERY ROM
The SATA RAID controller rmware is stored on the ash ROM and
is executed by the I/O processor. The rmware can also be updat-
ed through the PCI-X/PCIe bus port or Ethernet port (if equipped)
without the need to replace any hardware chips. During the con-
troller rmware upgrade ash process, it is possible for a problem
to occur resulting in corruption of the controller rmware. With
our Redundant Flash Image feature, the controller will revert back
to the last known version of rmware and continue operating.
This reduces the risk of system failure due to rmware crash.
1.7 Understanding RAID
RAID is an acronym for Redundant Array of Independent Disks. It
is an array of multiple independent hard disk drives that provides
high performance and fault tolerance. The SATA RAID control-
ler implements several levels of the Berkeley RAID technology.
An appropriate RAID level is selected when the volume sets are
dened or created. This decision should be based on the desired
disk capacity, data availability (fault tolerance or redundancy),
and disk performance. The following section discusses the RAID
levels supported by the SATA RAID controller.
The SATA RAID controller makes the RAID implementation and
the disks’ physical conguration transparent to the host operating
system. This means that the host operating system drivers and
software utilities are not affected, regardless of the RAID level
selected. Correct installation of the disk array and the control-
ler requires a proper understanding of RAID technology and the
concepts.
1.7.1 RAID 0
RAID 0, also referred to as striping, writes stripes 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 strip-
ing enhances performance because multiple drives are accessed