Need to import ~10TB of data from a content synced from a google storage. I have BTRFS file system (so CoW is available), and initialized it with

```
git annex initremote buckets type=directory importtree=yes encryption=none directory=../buckets/
```

and `../buckets` resides on the same mount point, so `cp --reflink=always ../buckets/....` works out nicely.

But when I have ran `git annex import --from=buckets -J 10 master` I saw that

- no `cp` is invoked by git-annex (according to `pstree`)
- I have equal amount of output IO as input IO (in `dstat`), suggesting that I am actually copying data

I have not done a really detailed look inside copied keys to see if they share storage extents etc, so my observation could still be wrong.

Joey, is it expected to take advantage of CoW with git-annex 8.20210223-1~ndall+1 in such a case or it is still a TODO?  any "workaround"? (e.g. may be I could just cp --reflink=always, git annex add, and then do import and annex would just reuse keys already CoWed?)

[[!meta author=yoh]]
[[!tag projects/datalad]]

> [[fixed|done]] --[[Joey]]
