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Conference msgaxp::optical

Title:Optical Products
Moderator:TAPE::SENEKER
Created:Wed May 04 1988
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:841
Total number of notes:3218

784.0. "problems with OSMS V3.3 and RW530" by VNABRW::KARTNER_M (HOUSTON, we have a problem) Thu Feb 13 1997 09:59

    Hi!
    
    I've got 2 questions concerning OSMS V3.3 (i think) on VMS V6.2
    with a RW530.
    
    a) are there any known OSMS SW problems that couse 
       MOUNTVERIFICATION TIMEOUTs on optical platters ?
       I think this should be a HW problem
    
    b) is there any restriction with optical platters concerning 
       VOLUMESETS ? Sorry. We have got no HW in our office so I
       can't check it out
    
    							thanks in advance
    							Michael
T.RTitleUserPersonal
Name		DateLines
784.1TAPE::SENEKERHead banging causes brain mushThu Feb 13 1997 11:4733
    There are no known problems in OSMS V3.3 on VMS V6.2 that will
    lead to mount verification timeouts but there have been some
    changes between V3.3 and the just released V3.4.  If you or a
    customer is having problems with V3.3 you should upgrade to V3.4
    and see if the problem is corrected.
    
    There are no restriction concerning volume sets, just definition
    of functionality and terms.
    
    o OSDS or OSMS supports Files-11 volume sets.
    
    o The WORMS-11 file system does not contain any construct for binding
      or attaching the on-disk structures of multiple disks to create a
      single logical volume.  In other words, no functionality similar to
      Files-11 volume sets is allowed for WORM media containing the
      WORMS-11 on-disk structure.
    
    There are some performance limitations concerning volumes sets.
    
    o Recommendation one, minimize the use volume sets to zero if possible.
    
    o Recommendation two, limit the number of volumes in the volume
      set to the number of drives in the jukebox.
    
    o Continuous use of a jukebox that is swapping at a maximal rate
      (thrashing) will exceed the mean time to failure in a little over
      a month.
    
    o If the number of volumes in the volume set are larger than the
      number of drives in the jukebox, expect platter thrashing and
      I/O throughput as low as 100 bytes per second.
    
    Rob
784.2LEFTY::CWILLIAMSCD or not CD, that's the questionThu Feb 13 1997 13:128
    One other performance limitation of Volume sets:
    
    Do not use both sides of the same platter in the same volume set.
    i.e. use JBA0, JBA2, JBA4 for a 3 volume set, not JBA0, JBA1, JBA2.
    Otherwise, the jb will swap itself to death.
    
    Chris