Resolving MAC OS/X folder frequent refreshes on an SMB file share

Recently working with a group of MAC users, I came across a very annoying issue. The user complains. How can I get rid of this annoying Folder Refreshes about every 30-60 seconds? The user explains. I am mounting a file share on my MAC, the file share has many files / folders(100k+), last, the file share is mounted using the SMB protocol. The Issue: In Finder, going to my folder destination, about every 30-60 seconds, the Finder folder structure refreshes, I then find my self back in the top root destination folder (extremely annoying). The user also claims, we did not have this issue in older versions of the OS (he doesn’t know the exact version the issue started) Solution: After researching the issue, the fowling solution fixed our issue. Create a file /etc/nsmb.conf – global option(if not exists) or it can be applied on a per user login, create a file/folder ~/Library/Preferences/nsmb.conf. Then, add these entry’s.

/etc/nsmb.conf
[default]
     smb_neg=smb3_only
     notify_off=yes

Note: The solution (and issue) was tested on MAC OS X El Capitan (version 10.11.5+). Solution explained: In some of the earlier versions, the protocol used for CIFS/SMB was 1.x, causing MAC/OS to behave different on refreshes (in fact you can still used that as a workaround by doing somthing like thiscifs://server@share/dir1). To note, since there is no refresh button in Finder, the MAC OS has to be smart enough to auto refresh whenever there is a file/directory change, in fact, there where many user’s complaining in older versions of MAC OS/X files/folder not getting refreshed (+workarounds for that). In latter releases (like ours) 10.11.5+ using SMB version 3.0, plus having notify_off=no(default), can cause constant folder structure refreshes, as a test changing to smb_neg=smb1_only will address the issue. we are forcing v3 as its many times faster then older releases.

Options available for nsmb.conf

Options available for /etc/nsmb.conf taken from the man page. Note: Apply changes with caution as it might have an adverse effect.

     The SMB library uses the following information for section names:

     A)      [default]
     B)      [SERVER]
     C)      [SERVER:SHARE]

     Possible keywords may include:

     Keyword             Section    Default    Comment
                         A B C      Values
     addr                - + -                 DNS name or IP address of
                                               server
     nbtimeout           + + -      1s         Timeout for resolving a NetBIOS
                                               name
     minauth             + + -      NTLMv2     Minimum authentication level
                                               allowed
     port445             + + -      normal     How to use SMB TCP/UDP ports
     streams             + + +      yes        Use NTFS Streams if server
                                               supported
     soft                + + +                 Make the mount soft
     notify_off          + + +      no         Turn off using notifications
     kloglevel           + - -      0          Turn on smb kernel logging
     smb_neg             + - -      normal     How to negotiate SMB 1/2/3
     signing_required    + - -      yes        Turn off smb client signing
     signing_req_vers    + - -      6          Bitmap of SMB Versions that
                                               have signing required
     validate_neg_off    + - -      no         Turn off using validate
                                               negotiate
     max_resp_timeout    + + -      30s        Max time to wait for any
                                               response from server
     read_async_cnt      + + -      4          Max async number of reads
     write_async_cnt     + + -      4          Max async number of writes
     dir_cache_async_cnt + + -      10         Max async queries to fill dir
                                               cache
     dir_cache_max_cnt   + + -      2048       Max entries to cache for a dir
     dir_cache_max       + + -      60s        Max time to cache for a dir
     dir_cache_min       + + -      30s        Min time to cache for a dir

Did you also run in to this issue? do you have a better solution?, Please let me know in the comments below.