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Conference decwet::winnt-clusters

Title:WinNT-Clusters
Notice:Info directories moved to DECWET::SHARE1$:[NT_CLSTR]
Moderator:DECWET::CAPPELLOF
Created:Thu Oct 19 1995
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:863
Total number of notes:3478

685.0. "PCBU x StorageWorks disks on NT Cluster" by VAXRIO::LEO () Thu Mar 13 1997 17:39

    Hi,
    
    	I have a customer that has 2 Prioris ZX 6200 and is buying the 
    FR-CK310-RF cluster kit.
    
    	Two questions :
    
    1)	He already has 2 internal FR-PCWVR-AZ (PCBU) disks on each machine.
    
    	But now he want to move 2 of these disks into the RAID Array 310.
    
    	I read the notes 296.6 and 296.7. They were very clear telling that
    the StorageWorks should be used instead of the PCBU ones.
    
    	The message was that StorageWorks disks had the rigth firmware and 
    appropiate tests in order to make sure that everything  works fine on WNT
    Cluster Environment.
    
        Is it still the reality today ?
    
    	Can I tell to my customer to use the  FR-PCWVR-AZ into the RAID Array
    310 instead of buying new SWXD3-WE disks ? 
    	
    2)  I read on several notes that the RAID Array 310 should be installed
    at the end of the SCSI BUS because it has already an internal
    termination. 
    
    	Is it still the reality today ?
    
    	If so, is there any plan to change that ?
    
    	Is there any special reason to put internal termination only
    on RAID Array 310 (neither RAID Array 410 nor RAID Array 450 have
    these internal terminators...) ? 
    	
    
	Thanks in advance,
    
    	Leo
    	Digital Technical Support
    	Brazil
T.RTitleUserPersonal
Name		DateLines
685.1nope...TROOA::MSCHNEIDER[email protected]Thu Mar 13 1997 17:478
    These are not the same disks despite the same enclosures (different
    colour).  These are not tested and in all likelihood will never be. 
    Will it work ... maybe ... will it be supported ... not today and maybe
    never, so the answer is to use the StorageWorks drives that are tested
    and supported.
    
    Sad that the PCBU stovepipe uses different disks.  The customer
    probably expected that he bought all this stuff from one company.
685.2VAXRIO::LEOThu Mar 13 1997 20:019
    Thank you for your prompt answer regarding question 1.
    
    Any comment about question 2 ?
    
    Regards,
    
    Leo                   
    Digital Technical Support
    Brazil
685.3MPOS01::naiad.mpo.dec.com::mpos01::cerlingI'[email protected]Fri Mar 14 1997 10:167
	I am not a StorageWorks expert, though I try to keep on on the stuff.
	I have not heard anything to say that the 310 will change from its
	current configuration.  Is it a problem that it has to be at the
	end of a SCSI chain?

tgc
685.4No plans to change Internal TermSUBSYS::VALLADARESSun Mar 16 1997 10:3612
Leo, 
    
    1. FR drives have different firmware and differnet geometry.  You
    cannot put them in a RA310 storage subsystem.
    
    2. The RA310 IS internally terminated.  There are no plans to change
    it. (but I'm real curious ... is this a large handicap in your market?)
    
    Julio Valladares
    Solutions for WinNT
    StorageWorks
685.5VAXRIO::LEOMon Mar 31 1997 17:4226
    Julio,
    
 >   2.The RA310 is internally terminated...is this a large handicap in your
 >   market ?
    
    So far it is not a real thing to be worry about. The main problem is that
    some field people, down here Brazil, get confuse in order to plan the 
    cluster installation. The common way when using RA410 (RA450) is to
    place the storage subsystem between the 2 Servers. I think it is not a
    real problem.
    
    Today I cannot make a more than 2 nodes WNT Cluster. But in a near
    future it will be possible.
                                                                    
    My new question is :
    
    The position of a storage subsytem, at end of the SCSI bus, on a
    configuration with 4 (or more) nodes could represent a potential 
    performance problem ? 
    
Best regards,
    
    	Leo
    
    	Digital Technical Support
    	Brazil
685.6MPOS01::naiad.mpo.dec.com::mpos01::cerlingI'[email protected]Tue Apr 01 1997 10:006
	Why would the position of the storage at the end of a SCSI bus
	create a performance problem?  Will the time it takes electrons
	to travel 12 meters be noticeable over travelling 6 meters?

tgc
685.7DECWET::CAPPELLOFMy other brain is a polymerTue Apr 01 1997 19:127
    No performance impact.  SCSI priority is determined by SCSI ID, not by
    distance between the initiator and target.  SCSI ID 7 is the highest
    priority, so it wins if two devices try to arbitrate for access to the
    bus at the same time.  That's why your SCSI host adapter is usually set
    to ID 7 by default.  Full priority order is
    7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8
685.8VAXRIO::LEOMon Apr 07 1997 18:491
    Thank you