FileServer-SambaFileSharing.md

Use Samba to Share Files on Raspberry Pi

Objective

This "recipe" provides a method for sharing files that are on your Raspberry Pi over a local area network. Specifically, this recipe addresses configuring a Raspberry Pi (RPi) as a file server to share a USB thumb drive. Since I also use a Mac, we'll illustrate sharing with a Mac client. Note however the process for sharing with a Windows or Linux client is very similar.

We will begin with a USB thumb drive that is physically plugged into a USB port on a RPi, AND mounted.

If you're unfamiliar with mounting an external drive on RPi, please review this recipe before proceeding. For this example the thumb drive has only a single partition formatted as an exFAT file system.

This recipe shows installation and configuration steps that should yield an operational Samba server on your RPi. At the conclusion, you should be able to access the shared USB thumb drive plugged into your RPi over a network connection to a Mac (or Windows or Linux).

Question: Why Do This At All?

Answer: Convenience. One could simply unmount the USB thumb drive on the RPi, remove it, and plug it into a USB port on the client. If your RPi is on the other side of your desk, perhaps that's not much convenience. If it's upstairs, or in the garage, or in another country (cautions), the convenience is more substantial. Another potential advantage is that Samba effectively translates the thumb drive's native file system format to SMB or CIFS - a near-universal standard. For example: if the thumb drive were formatted as ext4, it would be difficult-to-impossible for a Mac or Windows client to read or write the thumb drive.

As you'll see, Samba presents a distributed file system to its clients. Samba's distributed file system is called SMB (aka CIFS); but there are also other distributed file systems. You can refer to this article for more details on these distributed file systems, but ''in a nutshell'', the distributed file system allows disparate systems with vastly different native file systems to share files across system boundaries.

Create a Samba "distributed file system server"

Here's how to do it:

1. Verify fstab entry for the external drive

Check that you have a valid mount point for the external drive you're going to share. You may do this by entering the lsblk command at the command line prompt as follows:

$ lsblk --fs
NAME        FSTYPE FSVER LABEL       UUID                                 FSAVAIL FSUSE% MOUNTPOINTS
mmcblk0
├─mmcblk0p1 vfat   FAT32 bootfs      4EF5-6F55                             453.3M    11% /boot/firmware
└─mmcblk0p2 ext4   1.0   rootfs      ce208fd3-38a8-424a-87a2-cd44114eb820   52.3G     5% /
# the external drive to be shared ↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓
sda
└─sda1      exfat  1.0   SANDISK16GB 67EB-734A                              12.2G    18% /mnt/usb 
# 
sdb
└─sdb1      f2fs   1.15              97bd5811-e1b6-4582-8bbf-862b4a957b10  925.6G     1% /mnt/bluessd

We see that our thumb drive (LABEL: SANDISK16GB; aka sda1) is mounted at MOUNTPOINT: /mnt/usb. We are "good to go".

The entry in etc/fstab that yielded this happy result was similar to this:

LABEL=SANDISK16GB /mnt/usb exfat defaults,nofail,noatime 0 0

2. Install Samba:

Before installing Samba, you could check to make sure it's not already installed:

$ apt-mark showmanual | grep samba

Assuming you don't have the samba package installed, proceed as follows:

$ sudo apt update
...

$ sudo apt install samba 
...

This should complete without error.

3. Configure Samba:

3.a Edit the Samba Configuration file

Samba configuration is done through the file /etc/samba/smb.conf. Make a backup copy of smb.conf, and then use your favorite editor to modify this file as follows:

$ sudo cp /etc/samba/smb.conf /etc/samba/smb.conf.bkup
$ sudo nano /etc/samba/smb.conf

Add the following lines to the tail of smb.conf:

[thumbdrive]              # the share name
Comment = Shared Folder
Path = /mnt/usb
Browseable = yes
Writeable = yes
only guest = no
create mask = 0700
directory mask = 0700
force user = pi           # if you are not user pi, change this to your user name

Note that the smb.conf file being modified here is the one that was installed by apt in Step 2 on a standard 'bookworm Lite' distro obtained from the raspberrypi.com website. I mention this to call attention to the fact that there are many possible settings for smb.conf files. If you need to do something "more elaborate", you may wish to peruse this link. If not, suggest you refer to the Samba project's configuration guide: Setting up Samba as a Standalone Server.

One other item to note from the smb.conf file: the [homes] directive under the Share Definitions section implements a feature that you may find useful. If left enabled (i.e. the default), /home/pi is exported as a 'read-only' Samba share! If you don't want this, you may delete or comment the lines in the [homes] directive.

3.b Add user pi to Samba's password database file

When we mount the exported Samba share, we'll authenticate as user pi. Samba knows nothing of pi's password under RPi OS, so we'll need to create a password using smbpasswd. You can use a different user/password if you like; I use pi with the same password because that's easiest for me. Adding pi's Samba password proceeds as follows:

$ sudo smbpasswd -a pi
New SMB password:
Retype new SMB password:
Added user pi.

And of course if you do not use the username pi, replace pi with whatever username you do use.

3.c Restart Samba to read the revised smb.conf file

Use the systemctl utility to restart the smbd service, and reload the revised /etc/samba/smb.conf file:

NOTE: Do not worry re the samba service; it includes the un-needed Domain Controller functions.

$ sudo systemctl reload smbd
$ systemctl status smbd
● smbd.service - Samba SMB Daemon
     Loaded: loaded (/lib/systemd/system/smbd.service; enabled; preset: enabled)
     Active: active (running) since Thu 2025-04-03 01:18:16 UTC; 9min ago
       Docs: man:smbd(8)
             man:samba(7)
             man:smb.conf(5)
    Process: 649 ExecCondition=/usr/share/samba/is-configured smb (code=exited, status=0/SUCCESS)
    Process: 651 ExecStartPre=/usr/share/samba/update-apparmor-samba-profile (code=exited, status=0/SUCCESS)
    Process: 711 ExecReload=/bin/kill -HUP $MAINPID (code=exited, status=0/SUCCESS)
   Main PID: 652 (smbd)
     Status: "smbd: ready to serve connections..."
      Tasks: 3 (limit: 766)
        CPU: 481ms
     CGroup: /system.slice/smbd.service
             ├─652 /usr/sbin/smbd --foreground --no-process-group
             ├─654 /usr/sbin/smbd --foreground --no-process-group
             └─655 /usr/sbin/smbd --foreground --no-process-group

Apr 03 01:18:15 rpi3b1 systemd[1]: Starting smbd.service - Samba SMB Daemon...
Apr 03 01:18:16 rpi3b1 systemd[1]: Started smbd.service - Samba SMB Daemon.
Apr 03 01:27:44 rpi3b1 systemd[1]: Reloading smbd.service - Samba SMB Daemon...
Apr 03 01:27:44 rpi3b1 systemd[1]: Reloaded smbd.service - Samba SMB Daemon.

And that's it... your Samba server is running, and ready for you to connect from Mac/Windows/Linux! If you need more help with Samba configuration, perhaps the Samba wiki is a good place to start.

4. Connecting to the Samba share from a Mac or Linux client:

• On a Mac: open a Finder window (or use one that's already open)
  • From keyboard, enter command-k, or click Go, Connect to Server...
  • In the Server Address field enter the URL of your RPi; e.g. smb://raspberrypi3b.local
  • Authenticate as user pi and password from 3.b above, click Connect

• To mount the Samba share from another Raspberry Pi (or any Linux client) using the CLI:

   $ sudo mount.cifs //raspberrypi3b/thumbdrive /home/pi/mymusic -o user=pi,password=XXXXXXX,rw