We faced pretty interesting issue: our MAC computers were very slow accessing the files on a file storage. It took 2 to 5 minutes just to list the folder content not even mentioning about copying the files. At the same time all Windows systems in the same subnet were working absolutely fine.
Dan Roncadin in his article How to fix slow SMB file transfer on OS X 10.11.5+ and MAC OS Sierra describes in details why it happens and what to do to fix the issue.
In a short word this is about SMB signing and here is a short instruction to disable it:
- On a MAC workstation go to the /etc folder
- Open the nsmb.conf file or create a new one with this name. The file does not exist after clean MAC OS installation.
- Edit the file and add this line into [default] section
- Save the file
- Un-mount and re-mount any smb shares
Note: Even thought Dan says about OS X 10.11.5 and higher, his solution fixed all our MAC starting with OS X 10.7