American Megatrends MegaRAID Express 500 - Manual (Page 91)

Chapter 7 Troubleshooting 77
Other Potential Problems
Topic Information
DOS ASPI MEGASPI.SYS, the MegaRAID DOS ASPI manager, uses
6 KB of system memory once it is loaded.
CD-ROM drives
under DOS
At this time, copied CDs are not accessible from DOS even
after loading MEGASPI.SYS and AMICDROM.SYS.
Physical Drive Errors To display the MegaRAID Manager Media Error and Other
Error options, press <F2> after selecting a physical drive
under the Physical Drive menu, selected from the Objects
menu. A Media Error is an error that occurred while
actually transferring data. An Other Error is an error that
occurs at the hardware level because of a device failure,
poor cabling, bad termination, signal loss, etc.
Virtual Sizing The Virtual Sizing option enables RAID expansion. Virtual
Sizing must be enabled to increase the size of a logical
drive or add a physical drive to an existing logical drive.
Run MegaRAID Manager by pressing <Ctrl> <M> to
enable Virtual Sizing. Select the Objects menu, then select
the Logical Drive menu. Select View/Update Parameters.
Set Virtual Sizing to Enabled.
BSD Unix We do not provide a driver for BSDI Unix. MegaRAID
Express 500 does not support BSDI Unix.
Multiple LUNs MegaRAID Express 500 supports one LUN per each target
ID. No multiple LUN devices are supported.
MegaRAID Express
Power Requirements
The Maximum MegaRAID Express 500 power
requirements are 15 watts at 5V and 3 Amps.
SCSI Bus
Requirements
The ANSI specification dictates the following:
The maximum signal path length between terminators is 3
meters when using up to 4 maximum capacitance (25 pF)
devices and 1.5 meters when using more than 4 devices.
SCSI devices should be uniformly spaced between
terminators, with the end devices located as close as
possible to the terminators.
The characteristic impedance of the cable should be 90 +/-
6 ohms for the /REQ and /ACK signals and 90 +/- 10 ohms
for all other signals.
The stub length(the distance from the controller's external
connector to the mainline SCSI bus) shall not exceed.1m
(approximately 4 inches).
The spacing of devices on the mainline SCSI bus should be
at least three times the stub length.
All signal lines shall be terminated once at both ends of the
bus powered by the TERMPWR line.