How many threads is robocopy really using?

Question

I'm trying to copy a huge number of small files (30M x 150k) from one server to another over a network, like this:

robocopy sourceDir \\1.2.3.4\destDir /s /MT:32 /NP /LOG:d:\robocopy.log

The copy is working, but I see that according to Task Manager, robocopy.exe is only running two threads -- not the 32 I specified. Anybody know why?

if you don't specify the MT option does it run the default of 8 threads (current version)? What OS? — TheCleaner, Jul 22 '13 at 18:00

score 3 · Answer 1 · answered Oct 29 '15 at 09:09

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Opening up resource monitor on the target machine under Disk Activity you can see what files are currently being written to disc, ie how many threads are currently in use. /MT:32 uses 32 threads as expected.

answered Oct 29 '15 at 09:09

codaamok

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score 1 · Answer 2 · answered Jul 24 '13 at 18:27

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Looks like it only uses two threads when it's figuring out what to copy, then spun up another 32 once it got busy copying files. I should test this again to verify, but I haven't yet.

answered Jul 24 '13 at 18:27

Jesse

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How many threads is robocopy really using?

2 Answers2