[comp.sys.dec] Increasing DU Devices

ciaraldi@cs.rochester.edu (Mike Ciaraldi) (09/01/88)

I am helping someone with a PDP-11/73 system running RT-11 and TSX.
He had one Control Data 182 Megabyte disk drive.
Under RT-11 and TSX, he addressed it as device type "DU".
Since these operating systems only allow a disk drive to be
a maximum of 32 Mb, we had to partition the drive using 
the SET DUn command.
So, he had DU0: as the first 32Mb on the drive, DU1 as the next, and
so on.

Well, he just bought a second drive of the same type and size.
The problem is that under RT-11 and TSX you can only have eight
disk devices of one type, e.g. DU0 through DU7.
So, if he uses 5 or 6 partitions of the first drive, he can only
use 2 or 3 on the second drive.  Or he can use 4 partitions on each drive,
but that wastes 40 Mb from each drive.

I have heard of new drivers that let you have more partitions on-line
at the same time, e.g. DU0 through DU7, plus, say, DV0 through DV7,
even though the drives are on the same controller.

Does anyone have experience with these?

I talked with someone who tried a driver he got from DECUS, and
he said he had a lot of subtle problems on his 11/73, caused by
slight incompatibilities with the 11/23 the author used. Has anyone
tried it?

I have also heard of a commercial product from a company called,
I think, Network Dynamics, though I haven't been able to contact them
yet.  Has anyone dealt with them or other companies with similar products?

Thanks for the help.

Yours for greater disk space,

Mike Ciaraldi
...rutgers!rochester!ciaraldi