Conference ssag::ask_ssag

6568.0. "Opinions/Recommendations on configuration" by MSBCS::GRADY () Wed Apr 09 1997 12:37

    
    
	Hello,
    
        I would like your opinions/recommendations on the following
    	hardware disk configuration.
    
        I have a customer with several standalone 4700s' running VMS 6.2.
        They have an Informix database on a mixture of rz26s' and rz28s'in a
        SW 800 storageworks cab.
    
        They are running DSSI via HSD5s' and 10s'.  They have stripesets all 
    	on one shelf volumeshadowed to a set of disks on the next
        shelf etc.. this configuration works but they are looking for a
        better way to do it. The major concern is data availability not so much
        performance but performance will become an issue in the future as the 
        database grows.
    
        The system disk is also in the sw 800 shadowed.
    
           
    	*******************************************************************
              
        I would like to see them go to multiple KZPSAs' (two or four
        
        configured for redundancy) with dual redundant HSZ50s' using rz28s' or
    	
        rz29s'. I would suggest that stripesets be created vertically across 
    	
        the shelves then the stripesets be mirrored and the devices accessed 
    	
    	that way without being volumeshadowed. I would also recommend that 
    	
        spareset disks be used to take care of any stripe failures. Cable the 
    	
    	KZPSAs' so that each shelf is accessed by both controllers then 
    	
    	configure the HSZs' with preferred IDs' for better i/o tranfer.
        
    	If there are too many gotchas in this configuration I could
        still recommend using Volume shadowing, but across the shelves
        vertically and create either mirrored stripesets or volume sets
        mirrored which ever would be prone to the best i/o
    
        As you my gather I am not all that up on all the pros and cons
        of Volumeshadowing, but I have configured HSZs' in somewhat of the
        config I have just described.
    
        Any suggestions or info on what I can and can't do or any
        questions I can answer or recommendatiosn would really be appreciated.
    
        I will be monitoring this notes file daily.
                                                    
        						Thanks in advance
    
        							Dennis
    	
    
    
    
    
    
    
    
    
    
    
    
    
    
    

    If you are staying in the VAX world with 4700's you have two choices,
    DSSI with HSD50's and I would recommend using at least 4 DSSI rails for
    performance (depending on capacity), or CI.  Actually forget CI because
    4700's don't support it.  If you are moving to Alpha and you do not
    need clustering then you could move to dual redundant Raid 450's.
    
    Get in touch with your Storage Specialist and they should be able to
    help you out.
    
    Regards,
    
    JP Lavigne