Fixes for poor SMB client performance on macOS

Measures

  1. sudo vim /private/etc/nsmb.conf 
    # /etc/nsmb.conf - macOS 11.3 - 2021-04-29
#------------------------------------------------------------------------------
# SMB configuration for macOS 11.3 <-> Synology
#------------------------------------------------------------------------------
# Additional information:
# -----------------------
# https://support.apple.com/de-de/HT211927
# https://support.apple.com/en-us/HT208209
# https://apple.stackexchange.com/questions/309016/smb-share-deadlocks-since-high-sierra
# https://photographylife.com/afp-vs-nfs-vs-smb-performance
# https://support.apple.com/de-de/HT212277
#------------------------------------------------------------------------------
[default]
# Use NTFS streams if supported
streams=yes
 
# Soft mount by default
soft=yes
 
# Disable signing due to macOS bug
signing_required=no
 
# Disable directory caching
dir_cache_off=yes
 
# Lock negotiation to SMB2/3 only
# 7 == 0111  SMB 1/2/3 should be enabled
# 6 == 0110  SMB 2/3 should be enabled
# 4 == 0100  SMB 3 should be enabled
protocol_vers_map=6
 
# No SMB1, so we disable NetBIOS
port445=no_netbios
 
# Turn off notifications
notify_off=yes
 
# SMB Multichannel behavior
# To disable multichannel support completely uncomment the next line
# mc_on=no
 
# Some Wi-Fi networks advertise faster speeds than the connected wired network. 
mc_prefer_wired=yes
  2. Disable signing
    sudo defaults write /Library/Preferences/SystemConfiguration/com.apple.smb.server SigningRequired -bool FALSE
  3. Prevent reading .DS_Store files
    defaults write com.apple.desktopservices DSDontWriteNetworkStores -bool TRUE

Sources