Mylex DAC960PG, Installation Manual

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Installation
Manual No. 771971 3-13
Configuring the SCSI Devices
SCSI disk drives and other devices that will be connected to the controller
will need a certain amount of preparation before they are installed. This may
include setting jumpers to control termination power on the bus, drive spin-
up order, and parity protocols
Setting Device Termination Power
SCSI backplanes and cables connected to the DAC960PG should be
configured to apply SCSI terminator power. SCSI backplanes frequently
have this feature enabled. If not, SCSI disks can be configured to enable
terminator power, but be sure to enable SCSI termination power on the disks
only if termination power is not already supplied by the cabinet.
Refer to the documentation supplied with your SCSI cabinets and disk
drives.
The same rules also apply to ‘non disk’ SCSI devices connected to any of the
DAC960PG SCSI channels.
Setting Drive Spin-up & Parity Jumpers
If all of the SCSI drives are connected to a single power supply, or if the
power supply cannot supply the power needed to spin-up all of the drive
motors simultaneously, then the controller should be configured to spin-up
the drives separately. By spinning up the hard drives separately, the power
supply is not unnecessarily loaded by the large starting current required to
spin-up drives simultaneously. If drives are to be spun-up individually by the
controller, they may need to be shunted to spin-up on command, not at
power-on. See the specifications accompanying the SCSI drive for proper
jumper settings.
Also, the DAC960PG should be configured to spin-up the drives at regular
intervals by giving each drive a spin-up command. See the DACCF Utilities
Installation Guide and User Manual for more information on the disk drive
spin-up options. Tape and CD-ROM spin-up options should be left at the
factory defaults.
The drive parity jumpers, if any, should be set to always enable parity on the
SCSI data coming in, and to send parity with the data sent to the controller.