Adaptec AAA-130U2 Installation And Hardware Manual

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Adaptec AAA-130U2 Installation And Hardware Manual Manual pdf 22 page image

2-8AAA-130U2 Series Installation and Hardware GuideAdditional Hints for Connecting SCSI DevicesAll SCSI Devicesn If you are booting your system from a single SCSI hard disk orbootable array, the boot order (or virtual device order) of thehard disk or array must be set to 0. (See Making the Array Boota-ble on page 3-8.)n Enable termination power on all SCSI devices in the system sothat if you remove a drive that is supplying termination powerother devices will still provide it.n Symptoms of SCSI cabling-related problems are drives notbeing recognized, drives locking up, or drives that deactivate.n Use good-quality SCSI cabling, and minimize the stub lengths.Good-quality cables should not be limp when you pick themup. (See Appendix D, Obtaining SCSI Cables for additionalinformation.)Cable Lengthsn The total length of cabling (internal and external) on each SCSIchannel may not exceed the maximum lengths listed in thefollowing table:Maximum Cable Lengths for each SCSI ChannelMaximumCable Length Data Transfer RateMaximumDevicesSupported12 m (29.4 ft) Ultra2 (80 MBytes/sec) 11 Mixing Fast/Ultra devices with Ultra2 devices on the same channel causes thechannel to default to Ultra SCSI speeds and cable requirements.153 m (9.8 ft) Fast SCSI(10 MBytes/sec)73 m (9.8 ft) Wide SCSI(20 MBytes/sec)153 m (9.8 ft) Ultra SCSI(40 MBytes/sec for 16-bit (Wide),20 MBytes/sec for 8-bit)41.5 m (4.9 ft) Ultra SCSI(40 MBytes/sec for 16-bit (Wide),20 MBytes/sec for 8-bit)5-822 Ultra SCSI data transfer rates do not currently support more than eight devices.