Comment by cachius

Comment by cachius 14 hours ago

9 replies

rclone --multi-thread-streams allows transfers in parallel, like robocopy /MT

You can also run multiple instances of rsync, the problem seems how to efficiently divide the set of files.

cachius 13 hours ago

> efficiently divide the set of files.

It turns out, fpart does just that! Fpart is a Filesystem partitioner. It helps you sort file trees and pack them into bags (called "partitions"). It is developed in C and available under the BSD license.

It comes with an rsync wrapper, fpsync. Now I'd like to see a benchmark of that vs rclone! via https://unix.stackexchange.com/q/189878/#688469 via https://stackoverflow.com/q/24058544/#comment93435424_255320...

https://www.fpart.org/

pama 13 hours ago

Sometimes find (with desired maxdepth) piped to gnu-parallel rsync is fine.

SoftTalker 13 hours ago

robocopy! Wow, blast from the past. Used to use it all the time when I worked in a Windows shop.

  • bob1029 13 hours ago

    I am using robocopy right now on a project. The /MIR option is extremely useful for incrementally maintaining copies of large local directories.

adolph 11 hours ago

My go-to for fast and easy parallelization is xargs -P.

  find a-bunch-of-files | xargs -P 10 do-something-with-a-file

       -P max-procs
       --max-procs=max-procs
              Run up to max-procs processes at a time; the default is 1.
              If max-procs is 0, xargs will run as many processes as
              possible at a time.
  • akdev1l 10 hours ago

    note that one should use -print0 and -0 for safety

    • adolph 9 hours ago

      Thanks! I've been using the -F{} do-something-tofile "{}" approach which is also handy for times in which the input is one pram among others. -0 is much faster.

      Edit: Looks like when doing file-by-file -F{} is still needed:

        # find tmp -type f | xargs -0 ls
        ls: cannot access 'tmp/b file.md'$'\n''tmp/a file.md'$'\n''tmp/c file.md'$'\n': No such file or directory
      • elteto 9 hours ago

        You have to do `find ... -print0` so find also uses \0 as the separator.

      • akdev1l 8 hours ago

        find -print0 will print the files with null bytes as separators

        xargs -0 will use a null byte as separator for each argument

        printf 'a\0b\0c\0' | xargs -tI{} echo “file -> {}"