User manual

INTRODUCTION

1.4.2 Hot-Swap Disk Drive Support

The SATA RAID controller has built the protection circuit to sup-

port the replacement of SATA hard disk drives without having to

shut down or reboot the system. The removable hard drive tray

can deliver “hot swappable,” fault-tolerant RAID solutions at prices

much less than the cost of conventional SCSI hard disk SATA RAID

controllers. We provide this feature for controllers to provide the

advanced fault tolerant RAID protection and “online” drive replace-

ment.

1.4.3 Hot-Swap Disk Rebuild

A Hot-Swap function can be used to rebuild disk drives in arrays

with data redundancy such as RAID level 1, (10), 3, and 5. If a hot

spare is not available, the failed disk drive must be replaced with

a new disk drive so that the data on the failed drive can be rebuilt.

If a hot spare is available, the rebuild starts automatically when a

drive fails. The SATA RAID controller automatically and transpar-

ently rebuilds failed drives in the background with user-deﬁnable

rebuild rates. The SATA RAID controller will automatically restart

the system and the rebuild if the system is shut down or powered

off abnormally during a reconstruction procedure condition. When

a disk is Hot Swap, although the system is functionally operational,

the system may no longer be fault tolerant. Fault tolerance will be

lost until the removed drive is replaced and the rebuild operation

is completed.

1.5 Understanding RAID

RAID is an acronym for Redundant Array of Independent Disks. It is

an array of multiple independent hard disk drives that provide high

performance and fault tolerance. The SATA RAID controller imple-

ments several levels of the Berkeley RAID technology. An appropri-

ate RAID level is selected when the volume sets are deﬁned or cre-

ated. This decision is based on disk capacity, data availability (fault

tolerance or redundancy), and disk performance. The following is the

RAID level, which support in the SATA RAID controller.

The SATA RAID controller makes the RAID implementation and the

disks’ physical conﬁguration transparent to the host operating sys-

tem. This means that the host operating system drivers and software