[Info-vax] HZS70 Unit number question

[Michael Austin]

Jeffrey H. Coffield wrote:
> 
> bill.hall at nav-international.com wrote:
>> On Apr 24, 12:07 pm, "Jeffrey H. Coffield"
>> <jeff... at digitalsynergyinc.com> wrote:
>>> I have two Alphas (not clustered) connected to a HSZ70 that currently
>>> has units D0 through D5 showing as DKC0 through DKC5. DKC0 through DCK4
>>> are mounted on one system and DKC5 is mounted on the other.
>>>
>>> I have added some disks and want to add some new units but am concerned
>>> about the SCSI disk numbering and the unit numbering. AFAIK the SCSI
>>> controller takes a unit number (usually 7) so you could only have DKA0
>>> through DKA6 on a bus.
>>>
>>> I have read the CLI reference manual on the HSZ70 and can't see any
>>> mention of there being a conflict between the unit number and the SCSI
>>> addressing. It does say that a controller can present up to 8 units on
>>> each target ID number. Both controllers show a SCSI target(s) of (0).
>>>
>>> I only want to add two more units which would be DKC6 and DKC7 although
>>> what the actual disk unit is is not important.
>>>
>>> Jeff Coffield
>> Jeff,
>>
>> As you have your HSZ70 configured, you can "add unit" D0 through D7.
>> You can add additional target addresses to your controllers that will
>> allow more units (and do some load balancing if you have redundant
>> controllers).
>>
>> set this_controller id=(0,1,2,3)  ! up to 8 target id's, but must be
>> unique on the host scsi bus, hosts are usually 6 and 7
>>
>> This command will allow the controllers to present unit numbers 0-7,
>> 100-107,200-207, and 300-307.
>>
>> Bill
> 
> AHA, a CFL (green for lightbulb) comes on!.
> 
> DKA0 is really DKA000 and is SCSI id 0, SCSI id 1 is DKA100 so SCSI id 7
> would be DKA700, not DKA7.
> 
> Thanks to you and the others who replied so quickly.
> Jeff


SCSI or SAN/Fiber?  I know the HSG80 allowed devices to be configured to 
only be able to see certain servers - aka "selective presentation". 
This allows you to have any number of physical devices that can only be 
seen by the system as presented by the controller.