Hi,

I usually explain the ADSM backup to be an _image_ of the client's current 
data. Incremental backup then means updating that image: if a file is new,
a copy of it has to be put into the image; if a file has changed, it's copy
has to be replaced; and if a file has been deleted, it's copy has to be
removed from the image. 

Additionally to that, ADSM keeps the backup copies which have left the
image (the inactive ones) for some time according to management class 
settings. It thus is possible to restore to older points in times, if the
backup copies involved are still there. Only at this point, the management 
class comes in; as long as a backup copy belongs to the image (i.e. it is 
active), it is never deleted.

Hough, Peter writes:
 > I am a great fan of ADSM's incremental forever design. However, I sometimes
 > have difficulty explaining the concept to users, particularly those IT
 > people who are used to the traditional meaning of an incremental backup
 > (i.e. something which has to be used with previous incrementals and a full
 > backup).
 > Does anyone have any material that they are prepared to share which explains
 > the incremental forever concept in an easily understood manner?  Anything
 > would be much appreciated since it is bound to be better than my attempts so
 > far!!
 > 
 > Peter Hough
 > Guardian dr
-- 
Reinhard Mersch                        Westfälische Wilhelms-UniversiReinhard 
Mersch                        Westfälische Wilhelms-Universität
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