HP OpenVMS Systems

Purpose of Standalone BACKUP?

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The Question is:

 
what purpose does a standalone backup
serve?
 

The Answer is :

 
  Why standalone BACKUP?  The same reason as any other backup operation,
  it allows you to archive a version of your data and your programs that
  can later be (reliably) restored.
 
  OpenVMS supports shared access to files, and file data caching in host
  memory.  Both can have implications around the validity of a disk backup,
  as applications (or the operating system itself) can have files open for
  write access and the contents may not be in an entirely consistent state.
  This means that the files that are the target of the BACKUP should be
  quiescent when the BACKUP is made, to ensure that the data is in a
  consistent state.
 
  With files accessed by applications, getting a consistent BACKUP can
  involve shutting down the applications, or using mechanisms implemented
  within the application to ensure the file contents are consistent.
 
  To ensure a reliable copy of the OpenVMS operating system itself, you
  should use a copy of OpenVMS or standalone BACKUP (standalone BACKUP is
  available on OpenVMS VAX only) in order to ensure that the target system
  disk is entirely quiescent.  OpenVMS holds a number of files open, and
  by nature of the operating system provides no way to achieve consistent
  BACKUPs of these open files.
 
  Standalone BACKUP can be on the same system disk as the operating system,
  on magtape media, or on another disk.  An additional copy of standalone
  BACKUP should be available on alternative media for use in the event of
  a problem with the system disk, otherwise the restoration of the system
  disk from BACKUP could be, uh, "interesting".
 
  Standalone BACKUP can also be used to archive application data, though
  most sites use on-line BACKUP for this.
 
  For further information, please see the OpenVMS System Management manuals.
 

  

     

     
answer written or last revised on ( 4-SEP-1998 )
     
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