[Info-vax] HZS70 Unit number question

[Jeffrey H. Coffield]

Michael Austin wrote:
> 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.

The HSZ70 I have is SCSI. Don't know if they made a fiber version. The
ADD UNIT 6 and 7 worked. I leave all the drives available as the second
system is a hot backup in case the first one fails.

Thanks again to all who answered.

Jeff Coffield
www.digitalsynergyinc.com