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Subject: Re: duperemove : some real world figures on BTRFS deduplication
To: Chris Murphy <lists@colorremedies.com>,
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On 12/09/16 16:43, Chris Murphy wrote:
>> If compression has nothing to do with this, then this is heavy
>> fragmentation.
> 
> It's probably not that fragmented. Due to compression, metadata
> describes 128KiB extents even though the data is actually contiguous.
> 
> And it might be the same thing in my case also, even though no
> compression is involved.

In that case you can quickly collapse physically contiguous ranges by
reflink-mv'ing (ie. a recent mv) the file across subvolume boundaries
and back. :)

-h