I talked with HP and was told that there are 16 targets on one FW SCSI.
Target 7 is reserved for the adapter which leaves a total of 15 targets for
use. Most external drives do not use LUNs so you can not have more that 15
drives on one SCSI. The exception to this rule is the XP and Symmetrix disk
arrays. These two disk arrays use logical drives for configuration into the
MPE/iX operating system. My contact at HP was able to tell me that the XP
uses 8 LUNs for each available target for a total of 120 drives on one SCSI
(15 available targets X 8 LUNs = 120 available addresses). If this theory
holds true with the Symmetrix you will be able to have 240 drives on one
SCSI (15 available targets X 16 LUNs = 240 available addresses). Of course
this higher number is unproven and I could not get my HP contact to commit
to anything higher than the 120. I'm not even sure I'd want to go with the
120 with out fully examining the reason for such a high number.

I would like to thank everybody who responded to my inquiry.

Rich Holloway
Systems Administrator
Providence Health Plans
Phone: (503) 574-7457
Fax: (503) 574-8614
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http://www.providence.org

The opinions expressed are not necessarily those of my company. They belong
solely to me.

If everything seems under control, you're just not going fast enough. --
Mario Andretti