[pups] Major/minor device numbers and device names for MSCP drives?

Johnny Billquist bqt at GW.SoftJAR.SE
Tue Jun 20 01:08:59 AEST 2006

On Sun, 18 Jun 2006, Robert Armstrong wrote:

>  Worse, what if the MSCP controller isn't a RQDX but is a real UDA/QDA ?
> Now the drives have their own MSCP unit numbers that can be anything from 0
> to 250 - where does this figure in?

Note that this isn't really anything special.
You can both have a RQDX with an extender card which allows you to set 
other unit numbers on RD disks, and if you have two UDA controllers, they 
could both have disks starting from number 0.

The other response about automatic numbering of disks is true of NetBSD, 
as well as Ultrix. However, I'm not sure that BSD2 do this.
Unfortunately I can't remember for sure.
But don't you actually tell the unit numbers in the configuration file, 
along with the controller? Or do BSD2 also do a full autodetect and 
connect of MSCP disks?

If not, it could work in several ways, but I would suspect that disks on 
the second controller would start with minor # 64 (8 disks * 8 partitions 
per disk is I believe the default). But that assumes that the first disk 
found will be "0", no matter what the physical unit number is set to. 
Unless of course, this also is set in the configuration file. :-)

>  Same question for TMSCP - what if I have more than one tape controller?
> This case is easier, though, since TMSCP controllers normally have only one
> drive associated with them.

Well, DEC only have TMSCP controllers with a single unit for the PDP-11. 
Third party controllers can have several units...


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