Emulex UD33 - DEC UDA50

Troy Bergstrand ncbergst at ndsuvax.UUCP
Thu Jul 14 07:17:53 AEST 1988


We just installed Emulex's UD33 disk controller on our VAX 780.  But 
unfortunately the installation did not complete without incident.

Our configuration:

Vax 11-780 12 Megabytes of memory 2 Unibus controllers
Unibus 1: UDA33 - 2 RA81, Interlan Ethernet Controller
Unibus 2: 11 DMF32's, 1  DH

We are running 4.3BSD Unix with no modifications to the uda or unibus code.

We desired to put both the UD33 and the UDA50 on the same unibus, Emulex
tells us this should work, but it didn't.  After setting the UDA50 jumpers
to the longest possible (10ms) DMA delay and setting the UD33 in the same
way and also reconfiguring the kernel to place the UD33 at different
unibus addresses we also got the same result.

That result was a hanging of the system on disk i/o.  I could run 
systat -vm and watch the disk requests and after a period of time there
would arise some situation where at least one of the disk requests would
not or could not be serviced.  After which near every other process on
the system would get stuck in the request queue behind the hung process.

So to get the new drive working we put the UD33 on the unibus 2 with the
communcation controllers and everything is ok there.

Has anyone succesfully installed a UD33 on a 4.3BSD unix system on the 
same unibus as an UDA50?
-- 
J. Troy Bergstrand      North Dakota State University,  Fargo, ND  58105
  UUCP:       		...!uunet!ndsuvax!ncbergst    
  BITNET:      		ncbergst at ndsuvax.bitnet
  ARPA,CSNET:   	ncbergst%ndsuvax.bitnet at cunyvm.cuny.edu



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