Many macOS administrators face issues when trying to automount SMB shares with non-root permissions. The traditional /etc/fstab approach often fails to respect uid and gid parameters, defaulting to root:wheel ownership regardless of configuration attempts.

Since OS X El Capitan, System Integrity Protection (SIP) has restricted direct filesystem modifications. While /etc/fstab still works for basic mounting, permission handling behaves differently than on Linux systems:

//server/share /Volumes/share smbfs nobrowse,url=smb://user:pass@server/share,uid=501,gid=20 0 0

The uid and gid parameters here are frequently ignored by the macOS automounter.

Here's a working approach that combines autofs with proper permission handling:

Step 1: Create automount map

sudo mkdir -p /etc/auto_smb
sudo nano /etc/auto_smb/shares

Add this configuration (replace placeholders):

sharename -fstype=smbfs,soft,nosuid,nobrowse,uid=501,gid=20 ://username:password@server/sharepath

Step 2: Configure automount master map

sudo nano /etc/auto_master

Add this line at the end:

/-    /etc/auto_smb/shares

Step 3: Create launchd plist for automount

Create /Library/LaunchDaemons/com.user.smbmount.plist:

    Label
    com.user.smbmount
    ProgramArguments
    
        /usr/bin/automount
        -vc
    
    RunAtLoad
    
    KeepAlive
    

To ensure the mount point has correct permissions before mounting:

sudo mkdir -p /Volumes/sharename
sudo chown 501:20 /Volumes/sharename
sudo chmod 775 /Volumes/sharename

After implementing this solution:

sudo automount -vc
ls -la /Volumes/sharename

Should show files with the correct user/group ownership. The share will automatically mount when accessed and remain available in headless mode.

For environments requiring credential management:

security add-internet-password -a username -s server -w password -r "smb "

This stores credentials in the Keychain, which can then be referenced in automount configurations.

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After spending considerable time battling SMB automounting on macOS Sierra, I've discovered several critical pain points that most documentation fails to address properly. The traditional /etc/fstab approach appears to work superficially, but completely ignores permission settings like uid and gid parameters, defaulting to restrictive root:wheel ownership.

The macOS implementation of SMB mounting has some peculiar behaviors:

• mount_smbfs doesn't properly respect POSIX permission flags
• System integrity protection interferes with /etc/fstab modifications
• Credential prompts break headless automation

Here's a working approach that combines launchd and a wrapper script:

#!/bin/bash
# /usr/local/bin/mount_smb_share.sh

MOUNT_POINT="/Volumes/NetworkShare"
SHARE_URL="smb://server/share"
CREDENTIALS_FILE="$HOME/.smbcredentials"

if [ ! -d "$MOUNT_POINT" ]; then
    mkdir -p "$MOUNT_POINT"
fi

mount -t smbfs \
    -o nobrowse,soft,noowners,uid=$(id -u),gid=$(id -g),credentials=$CREDENTIALS_FILE \
    $SHARE_URL $MOUNT_POINT

chmod 775 "$MOUNT_POINT"

Save this as /Library/LaunchDaemons/com.user.mountsmb.plist:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>com.user.mountsmb</string>
    <key>ProgramArguments</key>
    <array>
        <string>/usr/local/bin/mount_smb_share.sh</string>
    </array>
    <key>RunAtLoad</key>
    <true/>
    <key>KeepAlive</key>
    <false/>
    <key>AbandonProcessGroup</key>
    <true/>
</dict>
</plist>

Create ~/.smbcredentials with:

username=your_username
password=your_password
domain=WORKGROUP

Then set appropriate permissions:

chmod 600 ~/.smbcredentials

After loading the launchd service (sudo launchctl load /Library/LaunchDaemons/com.user.mountsmb.plist), verify with:

mount | grep smbfs
ls -la /Volumes/NetworkShare