  Disk data security erasure? (Remanence) 
 The Question is:
 
Hi!
My question is:
How can I erase all of my data from a disk, so
there is no_way_to_recover any data in the future?
Thanks,
Csabesz
 
 The Answer is :
 
  The command INITIALIZE/ERASE does what most would consider an acceptable
  job from OpenVMS software -- if the target disk is the system disk, you
  will want to boot from the OpenVMS Alpha CD-ROM media or another system
  disk in order to use this command.
 
  Those who are a bit more paranoid could worry about bad block revectoring
  in the disk hardware, and whether some snippet of the "erased" data might
  be retrievable through some extraordinary hardware-level measures.  (The
  defence against this can involve specialized software or controller-level
  tools that repeatedly attempt to write various patterns to each sector on
  the disk.)
 
  Those who are truly paranoid would worry about blocks which had actually
  been erased being retrieved through highly specialized hardware picking
  up residual magnetic flux from the previous contents -- the US NCSC has
  a standard on magnetic remanence (part of the "Rainbow Books" series) that
  will be of interest.  (The only defense against this threat generally
  involves grinding and then "slagging" the disk.)
 
  Related discussions include (841), (3926), (4286), (4598), (7320).
 
 Answer written or last revised on  30-NOV-2001 
