TR-3505 page 21 under the heading 4.4 deduplication and read reallcoation:
"...
A read reallocation scan does not rearrange blocks on disk that are shared between files by deduplication
on deduplicated volumes. Since read reallocation does not predictably improve the file layout and the
sequential read performance when used on deduplicated volumes, performing read reallocation on
deduplicated volumes is not supported. Instead, for files to benefit from read reallocation, they should be
stored on volumes that are not enabled for deduplication"