Slow SMB browsing

I struggled with this for a long time, finally figured it out today (for me, at least). The fix is server-side.

In your /etc/samba/smb.conf file on the server, add this line:

readdir_attr:aapl_max_access = no

I believe this can be set globally or on a per-share basis.

Restart the server with:

sudo service smbd restart

From the Samba documentation:

https://www.samba.org/samba/docs/current/man-html/vfs_fruit.8.html

readdir_attr:aapl_max_access = yes | no

Return the user's effective maximum permissions in SMB2 FIND responses. This is an expensive computation, setting this to off pretends the use has maximum effective permissions.

The default is yes.

So, it sounds like it might break some things with the Finder UI in regards to the share + user's permissions. For me, since this is just a personal NAS, it's a non-issue as my user has full permissions anyway.

Hopefully this helps some people.

We also suffer from this issue, directory listing and even worse transferrates are unbearably slow. Nothing we tried helped, neither settings the afore mentioned setting nor changing settings for SMB Version, Signing etc.

Between 10.12 and 13.x (and Intel and Apple M-Series) nothing really changed. We tried SAMBA-Server on Linux and native Windows Server with no difference - Apples SMB implementation 'smbfs' seems just completely borked:

Downloading a 100M sparse file from the same share to a M1 macBook Air:

1. Apple smbfs native mount (measured via rsync): ~ 1.6 Megabytes/s
2. samba4 smbclient (via macports): ~ 7.4 Megabytes/s
3. SSH/SFTP (rsync): ~ 6.8 Megabytes/s