HP OpenVMS Systems

Consequences of power failures?

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The Question is:

 
What are the consequences of abrupt power failures?
 

The Answer is :

 
  Most commonly, darkness and quiet -- punctuated by sounds of annoyance
  and/or puzzlement, and occasional yelps of pain from bumping into large
  and immutable objects prior to the activation of the emergency lights.
 
  Further, abrupt power failures can be viewed as an enabling technology
  that is designed to assist in convincing local managment that an
  investment in a UPS (Uninterruptable Power Supply) would be fruitful.
 
  In most cases, most applications will recover gracefully from a power
  failure, and little more than an ANALYZE/DISK/REPAIR will be needed to
  free up existing allocated storage left over from the host caches in
  use prior to the power outage.
 
  The results of a power failure can of course vary -- OpenVMS StorageWorks
  storage hardware is designed to permit an entire block of data to be
  written to completion, and databases and transaction-oriented applications
  can be (are) coded to perform all-or-nothing updates -- multi-block disk
  writes can obviously fail part way through, should the power fail.
 
  For critical OpenVMS systems, the configuraiton of a UPS, of system
  integrated battery backup (for those systems that offer it), a
  motor-generator or other alternative power source(s) are typically
  recommended for the host system, the peripherals, critical lights,
  and for key network hardware, as are batteries for the StorageWorks
  enclosures.  Discussions of clustering and particularly disaster
  tolerant clustering also apply.
 

  

     

     
answer written or last revised on ( 6-APR-2000 )
     
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