Re: btrfs defra

[Bernhard Duebi <bernhard@due.bi>]

On Thu, 2011-06-16 at 08:50 -0500, David Nicol wrote:
> >   Defrag works on individual files, and tries to find a contiguous
> > sequence of bytes to write the file's data to. In the process, the
> > current implementation will break any CoW duplication -- either within
> > single files (copies with cp --reflink=always) or files copied via
> > snapshotting.
> 
> 
> While it's obviously impossible to defrag and maintain deduplicated
> partial chunks simultaneously without some kind of compromise (the
> ideal form of which is just beyond the reach of this list
> participant's obviousness flashlight),  how difficult is it going to
> be to modify the current defrag implementation to hip the additional
> references to the file to the fact that a contiguous version (of an
> individual file) is now available and it's time to update their links
> too, after each file with multiple reflinks/snapshots to its current
> form has been copied to contiguous space?
> 
> Could Bernhard Duebi do it?

Unfortunately not, I'm just a system engineer with interest in storage.
I'm sorry to disapoint you.

Sincerely
Bernhard