What are maximum scsi cable lengths?

[James Brand]

We have D, K, and N class servers with HP scsi interfaces to EMC cabinets. We need to know the scsi specifications for these adapters. xstm doesn't show much, ioscan gives the following results:
D class: "Fast wide"
K class: "Fast wide"
N class: "Fast wide differential"

Are these 20MB or 40MB scsi interfaces, and what are the maximum cable lenghts allowed?

[A. Clay Stephenson]

These are Fast wide differential SCSI but more importantly they are High-Voltage Differential SCSI. The D's and K's only support HVD SCSI but the N box can support both LVD and HVD BUT NEVER via the same HBA. It oftens results in equipment death to mismatch these buses.

HVD SCSI is 20 MByte/s and supports cable lengths up to 25m.

LVD (sometimes called Ultra 2) SCSI can transfer at up to 80 Mbytes/s and supports a maximum bus length of 12m.

[Eugeny Brychkov]

Hello James,
good information source on general SCSI is at http://www.paralan.com/glos.html .
Eugeny

[Gregory Fruth]

Check out the table at:

http://www.scsita.org/terms/scsiterms.html

HTH

[James Brand]

Thanks to all!

Jim