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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

743.0. "Binaries on shared storage - Oracle" by MPOS01::naiad.mpo.dec.com::mpos01::cerling (I'[email protected]) Wed Apr 16 1997 15:48

	I had a customer pose an interesting scenario, and, though I would
	guess we don't technically support it, I was wondering if it would
	work.

	The customer asked if Oracle could be installed on the shared storage.
	Not just the data, but the binaries.  His situation was that Oracle
	would not be running at all unless the shared storage device on which
	it was installed was on the system.  Right now he regularly installs
	Oracle on a system by copying a 'vanilla' directory to a new system
	and then does something that updates the registry.  Since his method
	of 'installing' appears to work, I could not think of any reason why
	his goal of having the binaries on the shared storage wouldn't work
	also.

	Take this a step farther, and you could apply this to generic binaries
	that you would want to fail over.  You wouldn't have to 'install'
	applications, as long as the script started up the applications from
	the shared storage.  Obviously, the scripts would have to be local (or
	would they?).

tgc
T.RTitleUserPersonal
Name		DateLines
743.1MOVIES::WIDDOWSONRod OpenVMS Engineering. Project RockThu Apr 17 1997 05:528
    I'm not sure whether this answers the question, but there is no
    filesystem support for shared storage in NT.  Images will need to be on
    a filesystem.  Oracle's OPS can place it's data on a raw partition.
    
    Furthermore, NTFS cannot manage a readonly device, so you cannot have
    the same disk mounted to two nodes even in read only mode...
    
    Or was that not the question ?
743.2MPOS01::naiad.mpo.dec.com::mpos01::cerlingI'[email protected]Thu Apr 17 1997 10:0911
	No, that was not the question.  The shared storage I was referring to
	is the RAID Array xxx that is on the common SCSI between the two
	systems.  The information is stored in the NTFS, just like any of the
	other types of things you would fail over between the two systems.

	What I am getting at is a single copy of the binaries installed on
	the common storage subsystem (is that better?) instead of having all
	the space required for an Oracle install on two local disks.

tgc
743.3out of my depthMOVIES::WIDDOWSONRod OpenVMS Engineering. Project RockThu Apr 17 1997 10:191
    Is there a perf impact of not having the data locally ?
743.4failing app bins on shared/switched storageMPOS01::naiad.mpo.dec.com::mpos01::cerlingI'[email protected]Thu Apr 17 1997 10:2712
	Though performance is not the issue with the customer, I would guess
	that it might even be a performance benefit to have some of that
	information out on an HSZ-based controller instead of one that is
	shared with the system drive.

	The real question here, regardless of whether or not it is Oracle,
	is "Is it possible to place application binaries on the switched
	storage when that application is the application that is failing
	over?".

tgc
743.5LJSRV1::GOODMANThu Apr 17 1997 10:401
This configuration is not supported for Digital Clusters or Wolfpack.
743.6An idle thought...SNOFS1::HUMMERSTONI COULD MURDER A CURRYThu Apr 17 1997 19:355
    Is the customer trying to get away with only 1 Oracle license for the
    cluster? Since the application can only run on the system where the
    disks are mounted, they only need 1 very expensive license and not 2.
    
    Paul
743.7more clarificationMPOS01::naiad.mpo.dec.com::mpos01::cerlingI'[email protected]Fri Apr 18 1997 09:2723
re: .5

	As I stated in my base note, I expected it to not be supported.  That
	doesn't answer the question of whether or not it will work.  I can't
	think of any reason why it wouldn't, and I am curious.  Of course,
	that then begs the question of why shouldn't it be supported.  Since,
	in a failover environment, the first thing that has to happen is the
	disk is made available, it stands to logic that the files needed to
	be executed would now be available.  How is that any different from
	having the executables on a system disk?

re: .6
	The customer is only trying to get away from having to eat up so
	much disk space that is required for each install and to speed the
	installation process.  As I stated in the base note, this is a
	procedure that he is doing for installs of Oracle right now.  Rather
	than go through a full install, he copies the files and updates the
	registry.  It just made sense to him that he could copy the files
	to the shared storage and update the registry, making life for him
	a little easier, and the storage requirements a little less.  He is
	not trying to bypass any licensing requirements.

tgc
743.8What about the registry?DECWET::CAPPELLOFMy other brain is a polymerWed Apr 23 1997 13:1813
    Putting your binaries on shared storage, and only running them on the
    system where the disks are online SHOULD work.  I have seen problems
    with putting failover scripts on shared storage, but I don't understand
    the cause.  (Seems to be a problem of the script file still being open
    when the shared storage is put offline during a manual failover.)
    
    However, a big part of installation of modern programs on NT is setting
    up entries in the registry, which is not shared between machines. 
    Putting your binaries on shared storage doesn't do anything to help
    this problem.
    
    Wolfpack will have a registry replication API that should address part
    of this problem.