Chapter Four
RAID controller configuration
Controller Description
The VOYAGER 3000 is a SCSI to SCSI RAID controller specifically designed to provide
RAID 0, 1, 0+1, 3 or 5 capability to any host system equipped with a SCSI interface. It is
totally independent of the host system's operating system with all the RAID functions
performed by the controller hardware. In effect, it endows the host system with the high speed
and fault-tolerant disk storage operation of RAID technology. The VOYAGER 3000 has
comprehensive drive failure management that allows automatic reassignment to reserve blocks
when a bad sector is encountered during a write. Hot-swapping is supported through
automatic disconnection of a failed drive and detection of a fresh drive followed with
background rebuilding of the data. The controller also supports spare drive operation. All
these failure recovery procedures are transparent to the host system.
The controller is housed in a removable device canister which allows for minimum Mean
Time to Repair (MTTR) periods. It is configured as one host bus with up to two target buses
of 3-7 drives on each bus.
The controller hardware is pre-configured when it leaves the factory but it is the responsibility
of the user to configure the logical volumes according to the capacities and RAID levels.
Controller Configuration
This section covers configuration issues involved with the RAID system. Figure 4-2 shows a
logical
view of a Voyager 3001 configuration. In this case there are three SCSI buses
connected to the controller across the three channels. Channel 2 makes up the host SCSI bus
with channels 0 and 1 making up the target buses.
Figure 4-1 Front view of controller (within a canister)
