Samba
Samba is the standard Windows interoperability suite of programs for Linux and Unix. Since 1992, Samba has provided secure, stable and fast file and print services for all clients using the SMB/CIFS protocol, such as all versions of DOS and Windows, OS/2, Linux and many others.
To share files through Samba, see #Server section; to access files shared through Samba on other machines, please see #Client section.
Server
Installation
Samba is configured in the /etc/samba/smb.conf
configuration file, which is extensively documented in smb.conf(5).
Because the samba package does not provide this file, one needs to create it before starting smb.service
.
A documented example as in smb.conf.default
from the Samba git repository may be used to setup /etc/samba/smb.conf
.
- The default configuration sets
log file
to a non-writable location, which will cause errors - apply one of the following workarounds:- Change the log file location to a writable path:
log file = /var/log/samba/%m.log
- Change logging to a non-file backend solution:
logging = syslog
withsyslog only = yes
, or uselogging = systemd
- Change the log file location to a writable path:
- If required; the
workgroup
specified in the[global]
section has to match the Windows workgroup (defaultWORKGROUP
). - The example configuration file exposes the user's home directory to the network with write access. If you see this as a security risk, consider commenting out the entire
[homes]
section. See smb.conf(5) § The [homes] section for details.
smb.conf
file, run the testparm(1) command to check for syntactic errors.Enabling and starting services
To provide basic file sharing through SMB, enable/start smb.service
. See smbd(8) for details.
If you want to make your server accessible via NetBIOS host name, set the desired name in the netbios name
option in smb.conf
and enable/start nmb.service
. See nmbd(8) for details.
nmb.service
is not required. However, it is needed to access Samba servers by hostname (e.g. smb://hostname/
) for some hosts. If your network is only composed of machines running Windows 10 or later, consider installing a WSD daemon as well for your server to appear in the "Network" view.Make the server discoverable
Install the avahi package, then enable/start avahi-daemon.service
to make the samba server discoverable with Zeroconf. It should work for most non-Windows file managers (macOS Finder, various GUI-based file managers on Linux & BSD etc.)
If avahi-daemon.service
is not running, the server will still be accessible, just not discoverable, i.e. it will not show up in file managers, but you can still connect to the server directly by IP or domain.
Windows Explorer relies on the WS-Discovery protocol instead; see #Windows 1709 or up does not discover the samba server in Network view.
Configure firewall
If you are using a firewall, do not forget to open required ports (usually 137-139 + 445). For a complete list, see Samba port usage.
UFW Rule
A Ufw App Profile for SMB/CIFS is included by default with the default installation of UFW in ufw-fileserver
.
Allow Samba by running ufw allow CIFS
as root.
If you deleted the profile, create/edit /etc/ufw/applications.d/samba
and add the following content:
[Samba] title=LanManager-like file and printer server for Unix description=The Samba software suite is a collection of programs that implements the SMB/CIFS protocol for unix systems, allowing you to serve files and printers to Windows, NT, OS/2 and DOS clients. This protocol is sometimes also referred to as the LanManager or NetBIOS protocol. ports=137,138/udp|139,445/tcp
Then load the profile into UFW run ufw app update Samba
as root.
Then finally, allow Samba by running ufw allow Samba
as root.
firewalld service
To configure firewalld to allow Samba in the home zone, run:
# firewall-cmd --permanent --add-service={samba,samba-client,samba-dc} --zone=home
The three services listed are:
-
samba
: for sharing files with others. -
samba-client
: to browse shares on other machines on the network. -
samba-dc
: for Samba/Active Directory domain controller.
--permanent
ensures the changes remain after firewalld.service
is restarted.
Basic configuration
User management
The following section describes creating a local (tdbsam) database of Samba users. For user authentication and other purposes, Samba can also be bound to an Active Directory domain, can itself serve as an Active Directory domain controller, or can be used with an LDAP server.
Adding a user
Samba requires a Linux user account - you may use an existing user account or create a new one.
guest account
and may be used for shares containing guest ok = yes
, thus preventing the need of user login on that share.Although the user name is shared with Linux system, Samba uses a password separate from that of the Linux user accounts. Replace samba_user
with the chosen Samba user account:
# smbpasswd -a samba_user
Depending on the server role, existing File permissions and attributes may need to be altered for the Samba user account.
If you want the new user only to be allowed to remotely access the file server shares through Samba, you can restrict other login options:
- disabling shell -
usermod --shell /usr/bin/nologin --lock samba_user
- disabling SSH logons - edit
/etc/ssh/sshd_config
, change optionAllowUsers
Also see Security for hardening your system.
Listing users
Samba users can be listed using the pdbedit(8) command:
# pdbedit -L -v
Changing user password
To change a user password, use smbpasswd
:
# smbpasswd samba_user
1. Create a Linux user which anonymous Samba users will be mapped to.
# useradd guest -s /bin/nologin
2. Add the following to /etc/samba/smb.conf
:
/etc/samba/smb.conf
... [global] security = user map to guest = bad user guest account = guest [guest_share] comment = guest share path = /tmp/ public = yes only guest = yes writable = yes printable = no
Anonymous users will now be mapped to the Linux user guest
and have the ability to access any directories defined in guest_share.path
, which is configured to be /tmp/
in the example above.
Make sure that the Linux user guest
has the proper permissions to access files in guest_share.path
.
Also, make sure shares have been properly defined as per the Share Definitions section of smb.conf.default.
Advanced configuration
Enable symlink following
follow symlinks
option can be a security risk./etc/samba/smb.conf
... [global] follow symlinks = yes wide links = yes unix extensions = no
Then, restart smb.service
.
Enable server-side copy for macOS clients
Server-side copy eliminates the need to transfer data between the server and the client when copying files on the server. This is enabled by default, but it doesn't work with macOS clients. If you have macOS clients, you need to add the following configuration to smb.conf
and then restart smb.service
.
/etc/samba/smb.conf
... [global] fruit:copyfile = yes
Usershares is a feature that gives non-root users the capability to add, modify, and delete their own share definitions. See smb.conf(5) § USERSHARES.
- Create a directory for usershares:
# mkdir /var/lib/samba/usershares
- Create a user group:
# groupadd -r sambashare
- Change the owner of the directory to
root
and the group tosambashare
:# chown root:sambashare /var/lib/samba/usershares
- Change the permissions of the
usershares
directory so that users in the groupsambashare
can create files. This command also sets sticky bit, which is important to prevent users from deleting usershares of other users:# chmod 1770 /var/lib/samba/usershares
Set the following parameters in the smb.conf
configuration file:
/etc/samba/smb.conf
[global] usershare path = /var/lib/samba/usershares usershare max shares = 100 usershare allow guests = yes usershare owner only = yes
Add the user to the sambashare group. Replace your_username
with the name of your user:
# gpasswd sambashare -a your_username
Restart smb.service
and nmb.service
services.
Log out and log back in.
If you want to share paths inside your home directory you must make it accessible for the group others.
In the GUI, you can use Thunar or Dolphin - right click on any directory and share it on the network.
In the CLI, use one of the following commands, replacing italic sharename, user, ... :
# net usershare add sharename abspath [comment] [user:{R|D|F}] [guest_ok={y|n}] # net usershare delete sharename # net usershare list wildcard-sharename # net usershare info wildcard-sharename
Set and forcing permissions
Permissions may be applied to both the server and shares:
/etc/samba/smb.conf
[global] ;inherit owner = unix only ; Inherit ownership of the parent directory for new files and directories ;inherit permissions = yes ; Inherit permissions of the parent directory for new files and directories create mask = 0664 directory mask = 2755 force create mode = 0644 force directory mode = 2755 ... [media] comment = Media share accessible by greg and pcusers path = /path/to/media valid users = greg @pcusers force group = +pcusers public = no writable = yes create mask = 0664 directory mask = 2775 force create mode = 0664 force directory mode = 2775 [public] comment = Public share where archie has write access path = /path/to/public public = yes read only = yes write list = archie printable = no [guests] comment = Allow all users to read/write path = /path/to/guests public = yes only guest = yes writable = yes printable = no
See smb.conf(5) for a full overview of possible permission flags and settings.
Restrict protocols for better security
server min protocol = SMB2_02
to protect yourself from ransomware attacks. In Samba 4.11 and newer, SMB2 is the default min protocol, so no changes are required there.Append server min protocol
and server max protocol
in /etc/samba/smb.conf
to force usage of a minimum and maximum protocol:
/etc/samba/smb.conf
[global] server min protocol = SMB2_10 ; server max protocol = SMB3
See server max protocol
in smb.conf(5) for an overview of supported protocols. For compatibility with older clients and/or servers, you might need to set client min protocol
or server min protocol
to an older protocol, but please note that this makes you vulnerable to exploits.
server min protocol = SMB3
when clients should only connect using the latest SMB3 protocol, e.g. on clients running Windows 10 and later.Clients using mount.cifs
may need to specify the correct vers=*
, e.g.:
# mount -t cifs //SERVER/sharename /mnt/mountpoint -o username=username,password=password,iocharset=utf8,vers=3.1.1
See mount.cifs(8) for more information.
Use native SMB transport encryption
Native SMB transport encryption is available in SMB version 3.0 or newer. Clients supporting this type of encryption include Windows 8 and newer, Windows server 2012 and newer, and smbclient of Samba 4.1 and newer.
To use native SMB transport encryption by default, set the server smb encrypt
parameter globally and/or by share. Possible values are off
, enabled
(default value), desired
, or required
:
/etc/samba/smb.conf
[global] server smb encrypt = desired
To configure encryption for on the client side, use the option client smb encrypt
.
See smb.conf(5) for more information, especially the paragraphs Effects for SMB1 and Effects for SMB2.
seal
mount option to force usage of encryption.Disable printer sharing
By default Samba shares printers configured using CUPS.
If you do not want printers to be shared, use the following settings:
/etc/samba/smb.conf
[global] load printers = no printing = bsd printcap name = /dev/null disable spoolss = yes show add printer wizard = no
Samba offers an option to block files with certain patterns, like file extensions. This option can be used to prevent dissemination of viruses or to dissuade users from wasting space with certain files. More information about this option can be found in smb.conf(5).
/etc/samba/smb.conf
... [myshare] comment = Private path = /mnt/data read only = no veto files = /*.exe/*.com/*.dll/*.bat/*.vbs/*.tmp/*.mp3/*.avi/*.mp4/*.wmv/*.wma/
Improve throughput
The default settings should be sufficient for most users. However setting the 'socket options' correct can improve performance, but getting them wrong can degrade it by just as much. Test the effect before making any large changes.
Read the smb.conf(5) man page before applying any of the options listed below.
The following settings should be appended to the [global]
section of /etc/samba/smb.conf
.
Setting a deadtime is useful to stop a server's resources from being exhausted by a large number of inactive connections:
deadtime = 30
The usage of sendfile may make more efficient use of the system CPU's and cause Samba to be faster:
use sendfile = yes
Setting min receivefile size allows zero-copy writes directly from network socket buffers into the filesystem buffer cache (if available). It may improve performance but user testing is recommended:
min receivefile size = 16384
Increasing the receive/send buffers size and socket optimize flags might be useful to improve throughput. It is recommended to test each flag separately as it may cause issues on some networks:
socket options = IPTOS_LOWDELAY TCP_NODELAY IPTOS_THROUGHPUT SO_RCVBUF=131072 SO_SNDBUF=131072
Enable access for old clients/devices
Latest versions of Samba no longer offer older authentication methods and protocols which are still used by some older clients (IP cameras, etc). These devices usually require Samba server to allow NTMLv1 authentication and NT1 version of the protocol, known as CIFS. For these devices to work with latest Samba, you need to add these two configuration parameters into [global]
section:
server min protocol = NT1 ntlm auth = yes
Anonymous/guest access to a share requires just the first parameter. If the old device will access with username and password, you also need the add the second line too.
Enable Spotlight searching
Spotlight allows supporting clients (e.g. MacOS Finder) to quickly search shared files.
Install and start/enable OpenSearch. Install fs2es-indexerAUR, configure the directories you want to index in /etc/fs2es-indexer/config.yml
, and start/enable fs2es-indexer.service
for periodic indexing.
Edit smb.conf
as described in the Samba wiki to enable Spotlight per share, and restart smb.service
to apply the changes.
Client
Install smbclient for an ftp
-like command line interface. See smbclient(1) for commonly used commands.
For a lightweight alternative (without support for listing public shares, etc.), install cifs-utils that provides /usr/bin/mount.cifs
.
Depending on the desktop environment, GUI methods may be available. See #File manager configuration for use with a file manager.
-
smbclient requires a
/etc/samba/smb.conf
file (see #Installation), which you can create as an empty file using thetouch
utility. - After installing cifs-utils or smbclient, load the
cifs
kernel module or reboot to prevent mount fails.
The following command lists public shares on a server:
$ smbclient -L hostname -U%
Alternatively, running $ smbtree -N
will show a tree diagram of all the shares. It uses broadcast queries and is therefore not advisable on a network with a lot of computers, but can be helpful for diagnosing if you have the correct sharename. The -N
(-no-pass
) option suppresses the password prompt.
smbtree
uses SMB1 and NetBIOS, which means they must be enabled on the servers and you need to set client min protocol = NT1
in smb.conf
on the client. Otherwise, smbtree
will show empty output.NetBIOS/WINS host names
Samba clients handle NetBIOS host names automatically by default (the behavior is controlled by the name resolve order
option in smb.conf
). Other programs (including mount.cifs
) typically use Name Service Switch, which does not handle NetBIOS by default.
The smbclient package provides a libnss driver to resolve NetBIOS host names. To use it, install it along with the samba package (which provides the winbindd daemon), start/enable winbind.service
and add wins
to the hosts
line in nsswitch.conf(5):
/etc/nsswitch.conf
... hosts: mymachines resolve [!UNAVAIL=return] files myhostname dns wins ...
winbind.service
, you may have to modify the unit file as described in this bug-report
Now, during host resolving (e.g. when using mount.cifs
or just ping netbios-name
), winbindd will resolve the host name by sending queries using NetBIOS Name Service (NBNS, also known as WINS) protocol.
By default it sends a broadcast query to your local network. If you have a WINS server, you can add wins server = wins-server-ip
to smb.conf
and restart winbind.service
, then winbindd and other Samba clients will send unicast queries to the specified IP.
If you want to resolve your local host name (specified in the netbios name
option in smb.conf
), start/enable nmb.service
, which will handle incoming queries.
You can test WINS resolution with nmblookup
. By default it sends broadcast queries to your local network regardless of the wins server
option.
Note that WINS resolution requires incoming traffic originating from port 137.
Disable NetBIOS/WINS support
When not using NetBIOS/WINS host name resolution, it may be preferred to disable this protocol:
/etc/samba/smb.conf
[global] disable netbios = yes dns proxy = no
Finally disable/stop winbind.service
.
Manual mounting
Mount the share using mount.cifs
as type
. Not all the options listed below are needed or desirable:
# mount --mkdir -t cifs //SERVER/sharename /mnt/mountpoint -o username=username,password=password,workgroup=workgroup,iocharset=utf8,uid=username,gid=group
The options uid
and gid
corresponds to the local (e.g. client) user/user group to have read/write access on the given path.
- If the
uid
andgid
being used does not match the user of the server, theforceuid
andforcegid
options may be helpful. However note permissions assigned to a file whenforceuid
orforcegid
are in effect may not reflect the real (server) permissions. See the File And Directory Ownership And Permissions section in mount.cifs(8) § FILE AND DIRECTORY OWNERSHIP AND PERMISSIONS for more information. - To mount a Windows share without authentication, use
"username=*"
.
uid
and/or gid
as mount options may cause I/O errors, it is recommended to set/check correct File permissions and attributes instead.-
SERVER
— The server name. -
sharename
— The shared directory. -
mountpoint
— The local directory where the share will be mounted. -
[-o options]
— See mount.cifs(8) for more information.
- Abstain from using a trailing
/
.//SERVER/sharename/
will not work. - If your mount does not work stable, stutters or freezes, try to enable different SMB protocol version with
vers=
option. For example,vers=2.0
for Windows Vista mount. - If having timeouts on a mounted network share with cifs on a shutdown, see wpa_supplicant#Problem with mounted network shares (cifs) and shutdown.
Storing passwords in a world readable file is not recommended. A safer method is to use a credentials file instead, e.g. inside /etc/samba/credentials
:
/etc/samba/credentials/share
username=myuser password=mypass
For the mount command replace username=myuser,password=mypass
with credentials=/etc/samba/credentials/share
.
The credential file should explicitly readable/writeable to root:
# chown root:root /etc/samba/credentials # chmod 700 /etc/samba/credentials # chmod 600 /etc/samba/credentials/share
Automatic mounting
systemd-networkd-wait-online.service
or NetworkManager-wait-online.service
(depending on your setup) to proper enable booting on start-up.Using NetworkManager and GIO/gvfs
NetworkManager can be configured to run a script on network status change. This script uses the gio command so that it mounts the Samba shares automatically, the same way your file manager does, as explained below. The script also safely unmounts the Samba shares before the relevant network connection is disabled by listening for the pre-down
and vpn-pre-down
events. Make the script is executable after creating it.
/etc/NetworkManager/dispatcher.d/30-samba.sh
#!/bin/sh # Find the connection UUID with "nmcli con show" in terminal. # All NetworkManager connection types are supported: wireless, VPN, wired... WANTED_CON_UUID="CHANGE-ME-NOW-9c7eff15-010a-4b1c-a786-9b4efa218ba9" # The user the share will be mounted under USER="yourusername" # The path that appears in your file manager when you manually mount the share you want SMB_URL="smb://servername/share" # Get runtime user directory. If it does not exist, do nothing and just exit XDG_RUNTIME_DIR=$(loginctl show-user --property=RuntimePath --value "$USER") || exit 0 if [ "$CONNECTION_UUID" = "$WANTED_CON_UUID" ]; then # Script parameter $1: network interface name, not used # Script parameter $2: dispatched event case "$2" in "up"|"vpn-up") su $USER -c "DBUS_SESSION_BUS_ADDRESS=unix:path=$XDG_RUNTIME_DIR/bus gio mount $SMB_URL" ;; "pre-down"|"vpn-pre-down") su $USER -c "DBUS_SESSION_BUS_ADDRESS=unix:path=$XDG_RUNTIME_DIR/bus gio mount -uf $SMB_URL" ;; esac fi
Create a symlink inside /etc/NetworkManager/dispatcher.d/pre-down
to catch the pre-down
events:
# ln -s /etc/NetworkManager/dispatcher.d/30-samba.sh /etc/NetworkManager/dispatcher.d/pre-down.d/30-samba.sh
As mount entry
This is a simple example of a cifs
mount entry that requires authentication:
/etc/fstab
//SERVER/sharename /mnt/mountpoint cifs _netdev,nofail,username=myuser,password=mypass 0 0
- See examples below on better security for authentication credentials
- Spaces in sharename should be replaced by
\040
(ASCII code for space in octal). For example,//SERVER/share name
on the command line should be//SERVER/share\040name
in/etc/fstab
. - To allow users to mount it as long as the mount point resides in a directory controllable by the user; i.e. the user's home, append the
users
mount option. The option is users (plural). For other filesystem types handled by mount, this option is usually user; sans the "s".
x-systemd.automount
if you want them to be mounted only upon access. See Fstab#Remote file system for details.As systemd unit
Create a new .mount
file inside /etc/systemd/system
, e.g. mnt-myshare.mount
. See systemd.mount(5) for details.
mnt-myshare.mount
can only be used if are going to mount the share under /mnt/myshare
. Otherwise the following error might occur: systemd[1]: mnt-myshare.mount: Where= setting does not match unit name. Refusing.
.What=
path to share
Where=
path to mount the share
Options=
share mounting options
- Network mount units automatically acquire
After
dependencies onremote-fs-pre.target
,network.target
andnetwork-online.target
, and gain aBefore
dependency onremote-fs.target
unlessnofail
mount option is set. Towards the latter aWants
unit is added as well. -
Append
noauto
toOptions
preventing automatically mount during boot (unless it is pulled in by some other unit). - If you want to use a hostname for the server you want to share (instead of an IP address), add
nss-lookup.target
toAfter
. This might avoid mount errors at boot time that do not arise when testing the unit.
/etc/systemd/system/mnt-myshare.mount
[Unit] Description=Mount Share at boot [Mount] What=//server/share Where=/mnt/myshare Options=_netdev,credentials=/etc/samba/credentials/myshare,iocharset=utf8,rw Type=cifs TimeoutSec=30 [Install] WantedBy=multi-user.target
To use mnt-myshare.mount
, start the unit and enable it to run on system boot.
automount
To automatically mount a share (when accessed, like autofs), one may use the following automount unit:
/etc/systemd/system/mnt-myshare.automount
[Unit] Description=Automount myshare [Automount] Where=/mnt/myshare [Install] WantedBy=multi-user.target
Disable/stop the mnt-myshare.mount
unit, and enable/start mnt-myshare.automount
to automount the share when the mount path is being accessed.
smbnetfs
First, check if you can see all the shares you are interested in mounting:
$ smbtree -U remote_user
If that does not work, find and modify the following line
in /etc/samba/smb.conf
accordingly:
domain master = auto
Now restart smb.service
and nmb.service
.
If everything works as expected, install smbnetfs.
Then, add the following line to /etc/fuse.conf
:
user_allow_other
Now copy the directory /etc/smbnetfs/.smb
to your home directory:
$ cp -a /etc/smbnetfs/.smb ~
Then create a link to smb.conf
:
$ ln -sf /etc/samba/smb.conf ~/.smb/smb.conf
If a username and a password are required to access some of the shared folders, edit ~/.smb/smbnetfs.auth
to include one or more entries like this:
~/.smb/smbnetfs.auth
auth "hostname" "username" "password"
It is also possible to add entries for specific hosts to be mounted by smbnetfs, if necessary.
More details can be found in ~/.smb/smbnetfs.conf
.
If you are using the Dolphin or GNOME Files, you may want to add the following to ~/.smb/smbnetfs.conf
to avoid "Disk full" errors as smbnetfs by default will report 0 bytes of free space:
~/.smb/smbnetfs.conf
free_space_size 1073741824
When you are done with the configuration, you need to run
$ chmod 600 ~/.smb/smbnetfs.*
Otherwise, smbnetfs complains about 'insecure config file permissions'.
Finally, to mount your Samba network neighbourhood to a directory of your choice, call
$ smbnetfs mount_point
Daemon
The Arch Linux package also maintains an additional system-wide operation mode for smbnetfs. To enable it, you need to make the
said modifications in the directory /etc/smbnetfs/.smb
.
Then, you can start and/or enable the smbnetfs
daemon as usual. The system-wide mount point is at /mnt/smbnet/
.
autofs
See Autofs for information on the kernel-based automounter for Linux.
File manager configuration
GNOME Files, Nemo, Caja, Thunar and PCManFM
In order to access samba shares through GNOME Files, Nemo, Caja, Thunar or PCManFM, install the gvfs-smb package.
Press Ctrl+l
and enter smb://servername/share
in the location bar to access your share.
The mounted share is likely to be present at /run/user/your_UID/gvfs
or ~/.gvfs
in the filesystem.
KDE
KDE applications (like Dolphin) has the ability to browse Samba shares built in. Use the path smb://servername/share
to browse the files. If you want to access files from on non-KDE application, you can install kio-fuse.
To use a GUI in the KDE System Settings, you will need to install the kdenetwork-filesharing package.
Other graphical environments
There are a number of useful programs, but they may need to have packages created for them. This can be done with the Arch package build system. The good thing about these others is that they do not require a particular environment to be installed to support them, and so they bring along less baggage.
- pyneighborhoodAUR
- LinNeighborhood, RUmba, xffm-samba plugin for Xffm are not available in the official repositories or the AUR. As they are not officially (or even unofficially supported), they may be obsolete and may not work at all.
Tips and tricks
If nothing is known about other systems on the local network, and automated tools such as smbnetfs are not available, you can manually probe for Samba shares.
First, install the nmap and smbclient packages.
Use nmap to scan your local network to find systems with TCP port 445 open, which is the port used by the SMB protocol. Note that you may need to use -Pn
or set a custom ping scan type (e.g. -PS445
) because Windows systems are usually firewalled.
$ nmap -p 445 "192.168.1.*"
Starting Nmap 7.92 ( https://nmap.org ) at 2022-03-13 12:00 UTC Nmap scan report for 192.168.1.1 Host is up (0.0011s latency). PORT STATE SERVICE 445/tcp open microsoft-ds Nmap scan report for 192.168.1.2 Host is up (0.00011s latency). PORT STATE SERVICE 445/tcp open microsoft-ds Nmap done: 256 IP addresses (2 hosts up) scanned in 2.45 seconds
The first result is another system; the second happens to be the client from where this scan was performed.
Now you can connect to their IP addresses directly, but if you want to use NetBIOS host names, you can use nmblookup(1) to check for NetBIOS names. Note that this will not work if NetBIOS is disabled on the server.
$ nmblookup -A 192.168.1.1
Looking up status of 192.168.1.1 PUTER <00> - B <ACTIVE> HOMENET <00> - <GROUP> B <ACTIVE> PUTER <03> - B <ACTIVE> PUTER <20> - B <ACTIVE> HOMENET <1e> - <GROUP> B <ACTIVE> USERNAME <03> - B <ACTIVE> HOMENET <1d> - B <ACTIVE> MSBROWSE <01> - <GROUP> B <ACTIVE>
Regardless of the output, look for <20>, which shows the host with open services.
Use smbclient(1) to list which services are shared on these systems. You can use NetBIOS host name (PUTER
in this example) instead of IP when available. If prompted for a password, pressing enter should still display the list:
$ smbclient -L \\192.168.1.1
Sharename Type Comment --------- ---- ------- MY_MUSIC Disk SHAREDDOCS Disk PRINTER$ Disk PRINTER Printer IPC$ IPC Remote Inter Process Communication Server Comment --------- ------- PUTER Workgroup Master --------- ------- HOMENET PUTER
Remote control of Windows computer
Samba offers a set of tools for communication with Windows. These can be handy if access to a Windows computer through remote desktop is not an option, as shown by some examples.
Send shutdown command with a comment:
$ net rpc shutdown -C "comment" -I IPADDRESS -U USERNAME%PASSWORD
A forced shutdown instead can be invoked by changing -C with comment to a single -f. For a restart, only add -r, followed by a -C or -f.
Stop and start services:
$ net rpc service stop SERVICENAME -I IPADDRESS -U USERNAME%PASSWORD
To see all possible net rpc command:
$ net rpc
Troubleshooting
Failed to start Samba SMB/CIFS server
Possible solutions:
- Check
smb.conf
on syntactic errors with testparm(1). - Set correct permissions for
/var/cache/samba/
and restartsmb.service
:
# chmod 0755 /var/cache/samba/msg
Permission issues on SELinux
SELinux not allow samba to access user home directories by default, to solve this, run:
# setsebool -P samba_enable_home_dirs 1
Similarly, samba_export_all_ro
and samba_export_all_rw
make Samba has the ability to read or "read and write" all files.
Permission issues on AppArmor
If using a share path located outside of a home or usershares directory, whitelist it in /etc/apparmor.d/local/usr.sbin.smbd
. E.g.:
/etc/apparmor.d/local/usr.sbin.smbd
"/data/" rk, "/data/**" lrwk,
After editing, reload the AppArmor profile:
# apparmor_parser -r /etc/apparmor.d/local/usr.sbin.smbd
No dialect specified on mount
The client is using an unsupported SMB/CIFS version that is required by the server.
See #Restrict protocols for better security for more information.
Unable to overwrite files, permissions errors
Possible solutions:
- Append the mount option
nodfs
to the/etc/fstab
entry. - Add
msdfs root = no
to the[global]
section of the server's/etc/samba/smb.conf
.
Set map to guest
inside the global
section of /etc/samba/smb.conf
:
map to guest = Bad Password
If you are still using Samba < 4.10.10, use Bad User
instead of Bad Password
.
Windows 10 1709 and up connectivity problems - "Windows cannot access" 0x80004005
This error affects some machines running Windows 10 version 1709 and later. It is not related to SMB1 being disabled in this version but to the fact that Microsoft disabled insecure logons for guests on this version for some, but not others.
To fix, open Group Policy Editor (gpedit.msc
). Navigate to Computer configuration\administrative templates\network\Lanman Workstation > Enable insecure guest logons and enable it.
Alternatively,change the following value in the registry:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters] "AllowInsecureGuestAuth"=dword:1
Error: Failed to retrieve printer list: NT_STATUS_UNSUCCESSFUL
If you are a home user and using samba purely for file sharing from a server or NAS, you are probably not interested in sharing printers through it. If so, you can prevent this error from occurring by adding the following lines to your /etc/samba/smb.conf
:
/etc/samba/smb.conf
[global] load printers = No printing = bsd printcap name = /dev/null disable spoolss = Yes
Restart the samba service, smb.service
, and then check your logs:
# cat /var/log/samba/smbd.log
and the error should now no longer be appearing.
Sharing a folder fails
It means that while you are sharing a folder from Dolphin (file manager) and everything seems ok at first, after restarting Dolphin the share icon is gone from the shared folder, and also some output like this in terminal (Konsole) output:
‘net usershare’ returned error 255: net usershare: usershares are currently disabled
To fix it, enable usershare as described in #Enable Usershares.
And you are using a firewall (iptables) because you do not trust your local (school, university, hotel) network. This may be due to the following: When the smbclient is browsing the local network it sends out a broadcast request on udp port 137. The servers on the network then reply to your client but as the source address of this reply is different from the destination address iptables saw when sending the request for the listing out, iptables will not recognize the reply as being "ESTABLISHED" or "RELATED", and hence the packet is dropped. A possible solution is to add:
iptables -t raw -A OUTPUT -p udp -m udp --dport 137 -j CT --helper netbios-ns
to your iptables setup.
For Uncomplicated Firewall, you need to add nf_conntrack_netbios_ns
to the end of the following line in /etc/default/ufw
IPT_MODULES="nf_conntrack_ftp nf_nat_ftp nf_conntrack_irc nf_nat_irc"
and then run the following commands as root:
echo 1 > /proc/sys/net/netfilter/nf_conntrack_helper ufw allow CIFS ufw reload
To make this change persistent across reboots, add the following line at the end of /etc/ufw/sysctl.conf
:
net.netfilter.nf_conntrack_helper=1
Protocol negotiation failed: NT_STATUS_INVALID_NETWORK_RESPONSE
The client probably does not have access to shares. Make sure clients' IP address is in hosts allow =
line in /etc/samba/smb.conf
.
Another problem could be, that the client uses an invalid protocol version. To check this try to connect with the smbclient
where you specify the maximum protocol version manually:
$ smbclient -U <user name> -L //<server name> -m <protocol version: e. g. SMB2> -W <domain name>
If the command was successful then create a configuration file:
~/.smb/smb.conf
[global] workgroup = <domain name> client max protocol = SMB2
Connection to SERVER failed: (Error NT_STATUS_UNSUCCESSFUL)
You are probably passing a wrong server name to smbclient
. To find out the server name, run hostnamectl
on the server and look at "Transient hostname" line
Connection to SERVER failed: (Error NT_STATUS_CONNECTION_REFUSED)
Make sure that the server has started. The shared directories should exist and be accessible.
Protocol negotiation failed: NT_STATUS_CONNECTION_RESET
Probably the server is configured not to accept protocol SMB1. Add option client max protocol = SMB2
in /etc/samba/smb.conf
.
Or just pass argument -m SMB2
to smbclient
.
Password Error when correct credentials are given (error 1326)
Samba 4.5 has NTLMv1 authentication disabled by default. It is recommend to install the latest available upgrades on clients and deny access for unsupported clients.
If you still need support for very old clients without NTLMv2 support (e.g. Windows XP), it is possible force enable NTLMv1, although this is not recommend for security reasons:
/etc/samba/smb.conf
[global] lanman auth = yes ntlm auth = yes
If NTLMv2 clients are unable to authenticate when NTLMv1 has been enabled, create the following file on the client:
/home/user/.smb/smb.conf
[global] sec = ntlmv2 client ntlmv2 auth = yes
This change also affects samba shares mounted with mount.cifs. If after upgrade to Samba 4.5 your mount fails, add the sec=ntlmssp option to your mount command, e.g.
mount.cifs //server/share /mnt/point -o sec=ntlmssp,...
See the mount.cifs(8) man page: ntlmssp - Use NTLMv2 password hashing encapsulated in Raw NTLMSSP message. The default in mainline kernel versions prior to v3.8 was sec=ntlm. In v3.8, the default was changed to sec=ntlmssp.
Mapping reserved Windows characters
Starting with kernel 3.18, the cifs module uses the "mapposix" option by default.
When mounting a share using unix extensions and a default Samba configuration, files and directories containing one of the seven reserved Windows characters : \ * < > ?
are listed but cannot be accessed.
Possible solutions are:
- Use the undocumented
nomapposix
mount option for cifs
# mount.cifs //server/share /mnt/point -o nomapposix
- Configure Samba to remap
mapposix
("SFM", Services for Mac) style characters to the correct native ones using fruit
/etc/samba/smb.conf
[global] vfs objects = catia fruit fruit:encoding = native
- Manually remap forbidden characters using catia
/etc/samba/smb.conf
[global] vfs objects = catia catia:mappings = 0x22:0xf022, 0x2a:0xf02a, 0x2f:0xf02f, 0x3a:0xf03a, 0x3c:0xf03c, 0x3e:0xf03e, 0x3f:0xf03f, 0x5c:0xf05c, 0x7c:0xf07c, 0x20:0xf020
The latter approach (using catia or fruit) has the drawback of filtering files with unprintable characters.
This section presupposes:
- Usershares are configured following previous section
- A shared folder has been created as a non-root user from GUI
- Guests access has been set to shared folder during creation
- Samba service has been restarted at least once since last
/etc/samba/smb.conf
file modification
For clarification purpose only, in the following sub-sections is assumed:
- Shared folder is located inside user home directory path (
/home/yourUser/Shared
) - Shared folder name is MySharedFiles
- Guest access is read-only.
- Windows users will access shared folder content without login prompt
Verify correct samba configuration
Run the following command from a terminal to test configuration file correctness:
$ testparm
Run the following commands from a terminal:
$ cd /var/lib/samba/usershares $ ls
If everything is fine, you will notice a file named mysharedfiles
Read the file contents using the following command:
$ cat mysharedfiles
The terminal output should display something like this:
/var/lib/samba/usershares/mysharedfiles
path=/home/yourUser/Shared comment= usershare_acl=S-1-1-0:r guest_ok=y sharename=MySharedFiles
Verify folder access by guest
Run the following command from a terminal. If prompted for a password, just press Enter:
$ smbclient -L localhost
If everything is fine, MySharedFiles should be displayed under Sharename
column
Run the following command in order to access the shared folder as guest (anonymous login)
$ smbclient -N //localhost/MySharedFiles
If everything is fine samba client prompt will be displayed:
smb: \>
From samba prompt verify guest can list directory contents:
smb: \> ls
If the NTFS_STATUS_ACCESS_DENIED
error is displayed, the issue is likely to be with Unix directory permissions. Ensure that your samba user has access to the folder and all parent folders. You can test this by sudoing to the user and attempting to list the mount directory, and all of its parents.
Mount error: Host is down
This error might be seen when mounting shares of Synology NAS servers. Use the mount option vers=1.0
to solve it.
Software caused connection abort
File managers that utilizes gvfs-smb can show the error Software caused connection abort
when writing a file to a share/server. This may be due to the server running SMB/CIFS version 1, which many routers use for USB drive sharing (e.g. Belkin routers). To write to these shares specify the CIFS version with the option vers=1.0
. E.g.:
/etc/fstab
//SERVER/sharename /mnt/mountpoint cifs _netdev,guest,file_mode=0777,dir_mode=0777,vers=1.0 0 0
This can also happen after updating Samba to version 4.11, which deactivates SMB1 as default, and accessing any Samba share. You can reenable it by adding
/etc/samba/smb.conf
[global] client min protocol = CORE
Connection problem (due to authentification error)
Be sure that you do not leave any space characters before your username in Samba client configuration file as follows:
~/.samba
username= user password=pass
The correct format is:
~/.samba
username=user password=pass
Windows 1709 or up does not discover the samba server in Network view
With Windows 10 version 1511, support for SMBv1 and thus NetBIOS device discovery was disabled by default. Depending on the actual edition, later versions of Windows starting from version 1709 ("Fall Creators Update") do not allow the installation of the SMBv1 client anymore. This causes hosts running Samba not to be listed in the Explorer's "Network (Neighborhood)" views. While there is no connectivity problem and Samba will still run fine, users might want to have their Samba hosts to be listed by Windows automatically. wsdd implements a Web Service Discovery host daemon. This enables (Samba) hosts, like your local NAS device, to be found by Web Service Discovery Clients like Windows. The default settings should work for most installations, all you need to do is start enable wsdd.service
.
If the default configuration (advertise itself as the machine hostname in group "WORKGROUP") should be all you need in most cases. If you need, you can change configuration options by passing additional arguments to wsdd by adding them in /etc/conf.d/wsdd
(see the manual page for wsdd for details).
wsdd2AUR does the same thing, but is written in C instead of Python. By default, it will look for the netbios name
and workgroup
values in smb.conf
.
See GNOME/Files#Windows machines (version 1709 or up) with shared folders don't show up in Network view.
Beginning with iOS/iPadOS 14.5 attempting to transfer from a device running iOS/iPadOS using the "Files" app to a samba share on Arch Linux will result in the error:
The operation couldn't be completed Operation canceled
To correct this problem, add add the following to the global section of your smb.conf
and restart smb.service
.
Comment optional:
## addition for iOS/iPadOS 14.5+ Files transfer-to server vfs object = fruit streams_xattr
See https://apple.stackexchange.com/q/424681 Apple.Stackexchange.com - "The operation couldn't be completed"/"Operation canceled" error message when saving to a Samba share via Files app.
Slow initial connections from certain clients without other performance problems
Some SMB clients, such as Solid Explorer for Android, take significantly longer to connect to Samba if they fail to resolve the NetBIOS name. Enabling nmb.service
will greatly speed up initial connections if this is the case. Since this is a bug in the client software, please report such cases to the authors of conflicting software.
CUPS managed printers are not listed
When Samba is configured to use CUPS for printing
/etc/samba/smb.conf
[global] printing = cups printcap name = cups
And the following symptoms occur:
-
smbclient -N -L <localhost>
does list any printers -
smbclient -N <localhost>/Your_Printer_Name
may return tree connect failed: NT_STATUS_BAD_NETWORK_NAME /usr/libexec/samba/samba-bgqd is not running
-
/var/log/samba/smbd.<hostname>
may contain the following entries. It's possible that the latest versions of samba do not use this file anymore
[2024/08/07 14:24:18.938740, 0] ../../source3/printing/printer_list.c:58(get_printer_list_db) get_printer_list_db: Failed to open printer_list.tdb
A workaround is to launch /usr/libexec/samba/samba-bgqd
manually (without parameters). Consider creating a systemd service to keep the binary running until the bug is fixed
Reference: Redhat Bug [1]
See also
- Official website
- Samba: An Introduction
- Samba 3.2.x HOWTO and Reference Guide (outdated but still most extensive documentation)
- Wikipedia
- Gentoo:Samba/Guide
- Debian:Samba/ServerSimple
- KSMBD - A linux kernel server which implements SMB3 protocol in kernel space for sharing files over network.