Bosch DVA-08K User Manual

en | Subsystem Connection and Operation

RAID Subsystem DVA-08K | Installation Manual

F.01U.027.797 | V2 | 2008.08

Bosch Security Systems

This chapter introduces sample topologies, configuration options and server connections for 

the RAID subsystems and discusses both the power on and power off procedures.

When you are configuring your storage subsystem, follow these basic rules:

•

Using a mix of LVD and legacy devices, such as devices using single-ended signaling, is 

not recommended. Use LVD terminators if all your devices support LVD signaling. Please 

refer to the documentation provided with your SCSI devices to avoid possible conflicts. 

•

When selecting the number of hard drives to be included in a logical configuration that 

should be presented through the host channels, the transfer rates and the mechanical 

performance of the hard disks should be considered. The combined bandwidth of the 

two SCSI host channels is 640MB/s, sufficient for most applications. If properly config-

ured, combining subsystems or drive enclosures may increase the number of drives and 

help to bring out the most of IOPs performance.

•

If you consider cascading multiple enclosures, considerations may include the character-

istics of your I/O load. Select the correct combination of optimization mode and a spe-

cific RAID level. 

•

An optimal configuration is always a compromise among different factors. For instance, a 

large array with many drive members may be more efficient, but the chance of failing a 

member is also increased.

•

The drives in the same logical array should have the same capacity; it is preferred that all 

the drives in the enclosure have the same capacity. 

•

A spare drive should have a minimum capacity equivalent to the largest drive that is to be 

replaced. If the capacity of the spare is less than the capacity of the drive to be replaced, 

then the controller will not proceed with the failed drive rebuild.