Samba - bridge between Linux and Windows

1. Approach

This docu documents install and usage of Samba.

Why yet another docu as all existings?

I have had problems with Samba also in the beginning of the 2000^th. And it seems it is not better yet. The most manuals explain only how to do, but not why and what’s happen.

2. Access from Windows to Linux

This requires a running samba service on the linux PC with a proper configuation.

2.1. Install Samba

On debian

sudo apt-get install samba

sudo apt-get install cifs-utils

The second line is for access Access from Linux to Windows

After change in the smb.conf:

sudo systemctl restart smbd.service

2.2. Samba config etc/

/etc/samba/smb.conf

Contains the configuration for the samba service. It is read on system start and reread if sudo service smbd restart is called. For a share append the following entry on end:

[data]
path = /mnt/data
force user = hartmut
public = yes
writable = yes
comment = smb share
printable = no
guest ok = yes
read only = no
create mask = 0777
directory mask = 777

[hartmut]
path = /home/hartmut
force user = hartmut
public = yes
writable = yes
comment = smb share
printable = no
guest ok = yes
read only = no
create mask = 0777
directory mask = 777

[data] and [hartmut] are the name of the net use connection = share, used in Windows in net use,
path = /path/to the path which is accessed with the share. The first path goes to the 'Data' directory, which is here an independent partition on hard disk mounted in the shown directory /mnt/data. The second entry is the path the home directory of me.

Note that it is recommended to hold independent data on an extra partition and not in the home directory. This helps on changing the operation system (Linux distribution etc).
force user = hartmut is the user name which is used for access to the files on path =. It means the /mnt/data/ should be accessible by hartmut as user on Linux. Set it with chusr and chgrp on creation or just chmod.
The rest may be obvious, it’s copied from some examples.

To edit smb.cnf you can use

sudo nano /etc/samba/smb.conf

nano is a simple text editor (better and newer than vi in my mind) but even with sophisticated but possible handling. It runs as console application, hence can edit immeditately root files with sudo.

Important hint: Paste content from clipboard is not intrinsically supported from nano, but because it’s an console application, you can use <ctrl-sh-V> as usual for konsole or other console applications to paste. It is received and executed by the console app and then interpret as key strokes for nano.

2.3. check whether Samba is installed, check the status, restart Samba

sudo smbstatus

This shows an overview of currently connected accesses (from Windows or other Linux).

systemctl status smbd
systemctl status smbd.service

Both effects the same and shows the status of any service, here from the smbd service which is Samba.

sudo systemctl restart smbd

This command is necessary to restart samba after the smb.conf was changed.

2.4. Network connection net use…

Now it is possible to make a network connection in Windows as usual between Windows PC. The batch script or command line version is:

set IP=192.168.2.70
ping %IP%
if exist R:\ subst E: /D
if exist R:\ net use R: /delete
net use R: \\%IP%\data /PERSISTENT:NO /USER:hartmut

IP is set as environment variable which is here 192.168.2.70 as the IP from the Linux PC.
ping the destination to see whether it is reachable in network, to see the situation is ok.
It may be possible that R: is mounted in Windows, with a subst or a network drive before, remove the subst or net use before.
On net use: The data is the share name.
Whether /USER:hartmut is used - not tested yet. It should be sufficient to determine the user on the Linux side. It is sufficient for Windows network connections. For the Linux side the entry force user = hartmut in the smb.conf is relevant.

3. Access from Linux to Windows

This requires additional to samba the cifs-utils. The older service smbfs is no more actually.

sudo apt-get install cifs-utils

After them any available network drive on Windows can be mounted. For that I use the following shell script, example which is executed on demand if necessary:

Script /batch/start/mnt-1-69-Q-T.sh:

ip a
IP="192.168.2.69"
ping $IP
if ! test -d /mnt/Qd; then
  sudo mkdir /mnt/Qd
  sudo chown hartmut /mnt/Qd
  sudo chgrp hartmut /mnt/Qd
  sudo mkdir /mnt/Qd/Qdata
  sudo mkdir /mnt/Qd/ramdisk
fi
echo umount /mnt/Qd/Qdata
echo umount /mnt/Qd/ramdisk
sudo umount /mnt/Qd/Qdata
sudo umount /mnt/Qd/ramdisk
ls /mnt
read -p "is unmounted ... press any Key" INPUT
##https://unix.stackexchange.com/questions/68079/mount-cifs-network-drive-write-permissions-and-chown
echo mount -t cifs -o user=hartmut,uid=$(id -u),gid=$(id -g) //$IP/tmp /mnt/Qd/ramdisk
sudo mount -t cifs -o user=hartmut,uid=$(id -u),gid=$(id -g) //$IP/tmp /mnt/Qd/ramdisk
ls /mnt/Qd/ramdisk
read -p "Tdata ... press any Key" INPUT
echo mount -t cifs -o user=hartmut,uid=$(id -u),gid=$(id -g) //$IP/D /mnt/Qd/Qdata
sudo mount -t cifs -o user=hartmut,uid=$(id -u),gid=$(id -g) //$IP/D /mnt/Qd/Qdata
ls /mnt/Qd/Qdata
read -p "Qdata ... press any Key" INPUT

Sets and uses the IP-address via the $IP variable.
This script creates, if not exists, the necessary folders in the /mnt directory.
Then it umount given
The D and tmp after the ip //$IP/ is the network name in Windows for the network drive (maybe a longer name, but for me it is the subst drive D:).
/mnt/Qd/data is the directory name on linux where the file tree is shown.
Interisting feature: Om my Windows PC the TMP directory is completely located in a RAM disk. The content of the RAM disk is not stored. All temporaries of Windows are not preserved. This runs. This TMP directory (on Windows on drive T:, e.g.) is mounted in network to allow storing data to exchange only on the RAM drive, saving access for the SSD (or also HDD).

Why use a second directory use /mnt/Qd/data instead /mnt/Qdata

That is experience:

The directory Qdata below mnt/Qd is used because the mounted drive on the other side (Windows) may have problems, e.g. computer is switched off after mounting, cable unplugged of an possible SSD via USB. Then the access to /mnt itself wold be wait till timeouts if the mount point is immediately below /mnt, The other mounted ressources cannot even be accessed, till the problem is detected and/or fixed. With the sub directory below mnt/Qd/… This access problems occurs only for /mnt/Qd and not already by the access to /mnt.

4. Unmount network drives

If an USB drive is disconnected, usual it is detected while unplug.

But a network drive can be available on mount, but later in the mounted state not available. Because for example the cable is unplugged or the computer is off. This is often after standby without unmount, then recover, but the other PC is not available.

sudo umount /home/Qd/data
sudo umount /home/Wd/ramdisk

started per command line, maybe also after login after wakeup from standby unmounts, and the mounting can be done with the call of the mount scripts again, see above.