Colin Raven wrote:
What happens if, once dedup is on, I (or someone else with delete
rights) open a photo management app containing that collection, and
start deleting dupes - AND - happen to delete the original that all
other references are pointing to. I know, I know, it doesn't matter -
snapshots save the day - but in this instance that's not the point
because I'm trying to properly understand the underlying dedup concept.
Logically, if you delete what everything is pointing at, all the
pointers are now null values, they are - in effect - pointing at
nothing...an empty hole.
I have the feeling the answer to this is; "no they don't, there is no
spoon ("original") you're still OK". I suspect that, only because the
people who thought this up couldn't possibly have missed such an
"obvious" point. The problem I have is in trying to mentally frame this
in such a way that I can subsequently explain it, if asked to do so
(which I see coming for sure).
Help in understanding this would be hugely helpful - anyone?
I mentally compare deduplication to links to files (hard, not soft) - as I
understand it, there is no "original" and "copy"; rather, every directory
entry points to "the data" (the inode, in ufs-speak), and if one directory
entry of several is deleted, only the reference count changes.
It's probably a little more complicated with dedup, but I think the
parallel is valid.
HTH
Michael
--
Michael Schuster http://blogs.sun.com/recursion
Recursion, n.: see 'Recursion'
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