Adaptec 131U2 - AAA RAID Controller Instrukcja Obsługi Pobierz pdf (Strona 22)

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AAA-130U2 Series Installation and Hardware Guide

Additional Hints for Connecting SCSI Devices

All SCSI Devices

■ If you are booting your system from a single SCSI hard disk or

bootable array, the boot order (or virtual device order) of the

hard disk or array must be set to 0. (See Making the Array Boota-

ble on page 3-8.)

■ Enable termination power on all SCSI devices in the system so

that if you remove a drive that is supplying termination power

other devices will still provide it.

■ Symptoms of SCSI cabling-related problems are drives not

being recognized, drives locking up, or drives that deactivate.

■ Use good-quality SCSI cabling, and minimize the stub lengths.

Good-quality cables should not be limp when you pick them

up. (See Appendix D, Obtaining SCSI Cables for additional

information.)

Cable Lengths

■ The total length of cabling (internal and external) on each SCSI

channel may not exceed the maximum lengths listed in the

following table:

Maximum Cable Lengths for each SCSI Channel

Maximum

Cable Length Data Transfer Rate

Maximum

Devices

Supported

12 m (29.4 ft) Ultra2 (80 MBytes/sec)

Mixing Fast/Ultra devices with Ultra2 devices on the same channel causes the

channel to default to Ultra SCSI speeds and cable requirements.

3 m (9.8 ft) Fast SCSI

(10 MBytes/sec)

3 m (9.8 ft) Wide SCSI

(20 MBytes/sec)

3 m (9.8 ft) Ultra SCSI

(40 MBytes/sec for 16-bit (Wide),

20 MBytes/sec for 8-bit)

1.5 m (4.9 ft) Ultra SCSI

(40 MBytes/sec for 16-bit (Wide),

20 MBytes/sec for 8-bit)

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Ultra SCSI data transfer rates do not currently support more than eight devices.

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