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Conference ssag::ask_ssag

Title:Ask the Storage Architecture Group
Notice:Check out our web page at http://www-starch.shr.dec.com
Moderator:SSAG::TERZAN
Created:Wed Oct 15 1986
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:6756
Total number of notes:25276

6630.0. "Which Volume Shadowing License w/ RAID Stripeset?" by NQOS02::nqsrv430.nqo.dec.com::SLOUGH (Dennis Slough; Novi, MI dtn 471-5154) Mon Apr 28 1997 09:47

Can I use one user-style (single disk) OpenVMS/VAX Volume Shadowing
license to mirror two HSD10-based stripesets of 4 physical drives each?

Seems ok to me, but I need a confirmation.

Dennis
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6630.1DUA/DIA = diskCSC32::M_DIFABIOMOVL #OPINION,EXE$GL_BLAKHOLEThu May 01 1997 16:338
    Dennis,
    
      Depends on what VMS see's. From your description the stripesets
    should appear as two DUA or DIA disks with equal geometry. Provided
    that is true, the single disk license should allow you to shadow 
    those 'two' disks.
    
             Mark d.
6630.2Another opinion entered here...NQOS02::nqsrv519.nqo.dec.com::SLOUGHDennis Slough; Novi, MI dtn 471-5154Thu May 01 1997 17:1511
Thanks for the reply.  I got a different opinion from the Sales Support Call 
Center after they did some research.  Their opinion is the license is based
on the actual number of physical disks in the controller-based RAID stripeset,
(actually both RAID stripesets totalled).  Surprised me.

This proposed solution is for a VAX 4000/500 which is in the Enterprise license 
tier.  Therefore a capacity license is not cost effective.  The good news from 
Digital's standpoint is this pushes the customer into an HSD50 pair to achieve
the dual redundant controller functionality they need.

Dennis
6630.3They are thinking software -based, or just wrongCSC32::M_DIFABIOMOVL #OPINION,EXE$GL_BLAKHOLEFri May 02 1997 18:428
    Dennis,
    
      I would ask Sales what utility on VMS they used to determine how
    many disks are in the controller based set. VMS has no idea what type
    of unit a controller is presenting. It could be a JBOD, Raid 0 set,
    0+1, Raid1, Raid5... But all VMS knows is that it is a DK/DU device.
    
                 Mark d.