Conference 7.286::fddi

2113.0. "DAP errors after Gigaswitch/FDDI installed" by GIDDAY::STANISLAUS () Thu Aug 15 1996 10:29

	

	BRS (Business Recovery System) or MDF (Multi Data Centre) configuration
with about 30 disks shadowed across the two sites.

Config: Two VAX 6xxx and one VAX 7xxx are members in a Cluster (CI and NI via
FDDI/T3 Microwave Link using Gigaswitches now and DL3000s before).

	Site 1						Site 2
	------						------


VAX 7xxx  VAX 6xxx						VAX 6xxx
	\ /						       /
	FGL4 in Giga1				  FGL4 in Giga2
	  \						/
	AGL+ in Giga1				  AGL+ in Giga2
	    \					       /
	To Microwave Radio T3 Link		  To Microwave Radio T3 Link
              \					      /
    	To Microwave Dish   			  To Microwave Dish
    
    
    
	Problems:
	---------

	Problem 1:
	----------

	When doing a network backup intermittently (one out of 3 times) on big
directory backups, we get DAP ERROR with a DAP CODE = 01F7A008.

  BACKUP-F-WRITEERR, Error writing saveset name
  -RMS-F-BUGDAP, Data access protocol error detected DAP code=01F7A008
%FAL-W-RMSABO, operation aborted due to internal error condition

	I decoded the above error using DAP specs to the following and I hope I 
am right. But I do not know what DAP MESSAGE RECEIVED OUT of SEQUENCE means.
May be a DAP guru can throw some light. Can a hardware failure between the
    source VAX and destination VAX path cause this problem. I know DAP CRC
    errors are mostly caused by H/W faults but I don't know this DAP ERROR.

	So 01F7   = problem reported by FAL (File Access Listner)
	A (Hex)   = 12 (octal) = DAP MESSAGE RECEIVED OUT OF SEQUENCE
	008 (Hex) = 10 (octal) = DATA MESSAGE

	Problem 2:
	---------

	2)Customer had one disk corruption on one member of a shadow set on 
site 1. The same data on site 2 was fine. The corruption was in a RMS indexed 
file. Ascii characters (+ signs) appeared in the file. The corruption was on 6
blocks of that file.


	Problem Start:
	--------------


	Problem started after the above Gigaswitches were installed last week 
to replace Digital Link's DL3000 FDDI to T3 Multiplexers.

	The Microwave Radio T3 equipment and the VAX 7xxx and VAX 6xxx systems
had no change done. They have exactly the same config now as they had when 
connected to the DL3000.

	Customer wants us to put back the DL3000 which is now an unsupported 
product and that is why we sold him the 2 Gigaswitches with AGL+ cards.
Gigaswitch version is 3.1.

	We have another site in Australia with the above config using AGL cards
and not AGL+ cards. 

	My next action plan is to replace the AGL+ cards with AGL cards for the
above problem customer. Any other suggestions.

	
Regards,
Alphonse