s3tools/s3cmd — pull request #59 by mdomsch (2012-06-18 20:27:05+00:00)
Title: Parallel destinations

(This

sync: add --add-destination, parallelize uploads to multiple destinations

Only meaningful at present in the sync local->remote(s) case, this
adds the --add-destination command line option. For the last
arg (the traditional destination), and each destination specified via
--add-destination, fork and upload after the initial walk of the local
file system has completed (and done all the disk I/O to calculate md5
values for each file).

This keeps us from pounding the file system doing (the same) disk I/O
for each possible destination, and allows full use of our bandwidth to
upload in parallel.