I am copying files to a remote with -J3 and keep seeing this pattern:

copy x (to remote..) ok
copy foo (to remote...)
47%   1.03 GiB         31 MiB/s 37s
copy bar (to remote...)
copy baz (to remote...)

Ie, there are 3 active jobs, but only one of them, typically the first of them, is actually copying. The other 2 are blocked on something which must be a resource the 1 is keeping busy.

That was with the remote having a path as an url. Changed it to localhost:path and 3 transfers ran concurrently with progress meters.

copy --from/get also runs concurrently, only --to has the problem.

Also, a copy --to a directory special remote runs concurrently. So only local path git remotes have the problem.

(Of course, there's often no benefit to parellizing writes to a disk as it will cause seeking, but -J requests it, and if the disk was a SSD, it would make sense to.)

git-annex version: 8.20201103 --Joey