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Conference cookie::hsm

Title:File Shelving
Moderator:COOKIE::HOLSINGER
Created:Mon Mar 15 1993
Last Modified:Thu Jun 05 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:346
Total number of notes:1204

343.0. "Opening shelved files from a MAC causes all files to be unshelved int hat directory " by CSC32::V_HEINICKE () Tue May 27 1997 11:02

    HSM 2.1
    V1.3 pathworks for MAC
    V5.0e pathworks for DOS and Windows
    ALPHA V 6.2
    
    Customer is trying to copy a shelved file on a MAC using pathworks 
    from a VMS system.  It appears to be copying only the header 
    information - his expectation is that it first unshelve the file and 
    then copy the file header/ text.  He can unshelve the file and then 
    copy the file from the MAC succesfully.
    
    He is also trying to open a file (on the MAC) that is shelved on the 
    VMS side. All files in that directory are currently shelved.  HSM 
    proceeds to unshelve all files from that directory rather than just 
    unshelving the requested file.  What would cause HSM to unshelve
    all files rather than just the requested file?
    
    We do not have a MAC and therefore cannot duplicate the behavior.
    
    Thanks,
    
    Victoria
T.RTitleUserPersonal
Name		DateLines
343.1HSM$FAULT_AFTER_OPEN ?ATZIS3::KARTNER_MHOUSTON, we have a problemWed May 28 1997 11:5521
    Hi!
    
    I do not now the pathworks part for the MAC exactly. If the standard
    Pathworks is used, the sunshelving is controlled by the following
    logical which is defined by default:
    
    	HSM$FAULT_AFTER_OPEN "PCFS_SERVER, PWRK$LMSRV"
    
    This logical is neccesary to avoid problems if a file isn't unshelved
    fast enough. If implemented HSM triggers the unshelving of the file
    and signals an access conflict to the client (PC,...) after some
    time you can hit the retry button to access the unshelved file.
    
    The faulting behaviour is set for all listed processes. You can
    add any process you want to this list. If PW via MAC uses other
    server processes you should add them to the list. If MAC is
    using the same servers the problem should be reproducable on
    PS's too.
    
    I've never seen the problem with unshelving all files. Do you
    explicitly open one specific file in the directory ?
343.2some ideas...COOKIE::HOLSINGERHSM Engineering, DTN 522-2843Wed May 28 1997 14:1511
Hi Victoria, 

Michael is correct, the FAULT_AFTER_OPEN should be used to jump-start the 
unshelve operation. However, this will also cause all which are opened by 
PathWorks to be unshelved, too. i.e. If PathWorks opens every file in a 
directory as a result of a directory command from the MAC. It really depends
upon what the MAC client is asking the VMS PathWorks server to do. 

Hope this helps, 
/Paul
343.3CSC32::V_HEINICKEWed May 28 1997 17:3525
    
    Hi,
    
    The customer has defined 
    
        FAULT_AFTER_OPEN "PCFS_SERVER, PWRK$LMSRV, MSAF$SERVER0"
    
    The MSAF$SERVER0 is the server for the MAC.  Therefore, if I understand
    what you said, when the copy of a file is done from the MAC (customer
    used ther terminolgy 'copy from the network share to the MAC) the file
    should first be unshelved and then copied (in its entirety) to the MAC.
    Currently this is not happening so what would cause only the file header
    to be copied to the MAC.  Could the unshelving be timning out, and if
    so, why would an error not be returned?
    
    On the open of a particular file unshelving all files in the directory,
    the open is done from an application.  The user then are given the
    directory of all files within a particular directory and they select
    the files they want HSM to specifically unshelve.  Since all files in
    the directory are being unshelved, how does the customer prevent
    the unshelving of all but the specific file requested?
    
    Thanks,
    
    Victoria
343.4Are the files opened by the applikation?ATZIS3::KARTNER_MHOUSTON, we have a problemFri May 30 1997 04:2010
    Hi!
    
    You are talking about an applikation. Is it written by your user?
    If this applikation really opens the files as stated (or does operations
    to them that do not affect the fileheader only) it's intended
    behaviour that the files get unshelved by HSM.
    
    I hope I didn't missunderstand you
    						bye	
    						Michael
343.5Michael is correctCOOKIE::HOLSINGERHSM Engineering, DTN 522-2843Wed Jun 04 1997 17:1631
Hi Victoria. 
It looks like two things are not working as expected. 

    1.	When the MAC server opens a shelved file, an information request is 
	set to HSM via the HSDRIVER. HSM completes the request as normal, but 
	the FAULT_AFTER_OPEN logical directs HSM to generate an implicit file 
	fault request, on behalf of the server. This is in anticipation of 
	subsequent read operations. With luck, the unshelve will occur before 
	the read is issued (and fails). 

	In the situation you describe, the unshelve does not occur in time. 
	There are a couple of things you can change, e.g. put the MAC's shelved 
	files on MO cache, this would greatly improve the unshelve time. 

	Also, you can use another logical, FAULT_ON_OPEN, which directs HSM to 
	suspend completion of the file info request until the data is unshelved.
	This method works better for some of the more "impatient" client/server
	systems. 

    2.	The fact that all files within a particular directory are getting 
	unshelved indicates that the MAC server is opening all these files, 
	even though the user application will open only a single file. This 
	behavior can not be compensated for by HSM, given use of either of the 
	logicals above. 

	This is unfortunate, as attributes of theses files can be read on VMS 
	by the server without actually having to open them. 
 

Hope this is clearer now. 
/Paul