Comment 10 for bug 1899249

You could shrink the DDT by making a copy of the files in place (with dedup off) and deleting the old file. That only requires enough extra space for a single file at a time. This assumes no snapshots.

If you need to preserve snapshots, another option would be to send|recv a dataset at a time. If you have enough free space for a copy of the largest dataset, this would work.