Samba File Sharing

You want Windows, macOS, and Linux machines to read and write the same directories over a home LAN. Which protocol does Samba implement to make that work?

In its original form SMB rode on top of NetBIOS. What three services did NetBIOS provide, and how do they map to familiar TCP/IP concepts?

How do modern Windows machines discover Samba servers now that the old SMB1 browsing has been removed for security reasons?

Starting from which Samba versions did SMB 2.0, SMB 3, and SMB 3.1 become supported?

In Samba terminology, what exactly is a share?

Under user-level security, what does Samba have to maintain that share-level password schemes do not?

Why is domain-level security more efficient for the server than plain user-level security, even though they look identical to the end user?

A standalone Samba server on a home LAN — which of the five SMB security models is it running, and what else can Samba act as since version 4?

You want to repurpose an old PC or a Raspberry Pi as a Samba-based NAS without hand-editing config files. What open-source option fits, and what hardware caveat applies to the Pi?

Samba runs two background daemons. What is the division of labour between nmbd and smbd?

In smb.conf, someone adds a comment on the same line as a parameter setting and Samba misbehaves. What is the rule about comments in this file?

Which smb.conf settings activate the user-level security model, and what happens if none of them are present?

Before reloading Samba after major smb.conf edits, which command checks for syntax errors, and how do you make it also reveal the defaults you never set?

You set 'interfaces' in smb.conf to restrict Samba to your LAN's address range, but it seems to have no effect. What did you forget?

An online guide tells you to re-enable SMB1 to fix a compatibility problem. Why should you refuse, and what does current Samba require by default?

On Fedora/RHEL your Samba config looks correct but home directories won't share. Which subsystem is silently blocking you, and how do you fix it for home dirs versus other directories?

The 'log file = /var/log/samba/log.%m' setting produces a flood of separate log files. What is %m doing, and why can that be a problem with logrotate?

Windows machines can't find your Samba server on the network. What package do you install on the Linux side to advertise it?

For a Samba user to work there must be a matching Linux account, yet the Linux account's password is irrelevant. Why does the Linux account still need to exist, and how do you keep it from being a login risk?

Which command creates a Samba account, and what must already exist on the system before it will succeed?

Where does modern Samba store its user passwords by default, and which command lists all Samba users with their attributes?

Samba and Linux passwords use different encryption and live in separate stores. When 'unix password sync = yes' is enabled, in which direction does synchronization flow?

Why can 'unix password sync = yes' silently leave a user's Samba and Linux passwords out of step, and what setting does the author recommend instead?

A Windows login name is longer or formatted differently than any Linux username. How do you make Samba accept it?

The username-map file (smbusers) is flagged as a security risk. What is the dangerous mapping to avoid, and how should the file be locked down?

A user working from a Windows PC against a Linux Samba server can end up juggling how many distinct credentials, and what is each one for?

You want to share a central directory with several colleagues, password-protected, but without handing out your own login password. What's the clean setup?

In a share's smb.conf section, what do 'valid users', 'path', and 'writeable' control, and what still gets the final say on access?

The special [homes] section carries 'browseable = no'. A newcomer assumes that hides each user's home directory from them — what does it actually do?

Setting up a shared group directory in Samba, which parameters ensure newly created files stay group-accessible, and what makes force group behave safely?

Why is 'force group = sales' without a leading plus sign a serious security hole compared with 'force group = +sales'?

How do you let unauthenticated Windows users reach a specific read-only share without giving them access to everything?

Deleting a file on a network share normally loses it for good — the local recycle bin doesn't apply. How does Samba provide a safety net?

When you right-click 'Share' a folder in GNOME Files or KDE Dolphin, what mechanism is used behind the scenes, and what group membership is required?

You shared a folder through the GNOME or KDE dialog but colleagues can't log in — only guest access works. What did the desktop tool not do for you?

When creating accounts for a multi-user home/company Samba server, why run useradd without a password, and what still has to be done afterward?

You want a share to be invisible to users who aren't allowed in. What can Samba actually do here, and why won't the obvious options solve it?

On a company Samba server, how do you let members of several different groups all reach the same shared directory?

For a Linux desktop to act only as an SMB client (not a server), which ports need to be open, and how do they differ from the server-side set?

In a GNOME or KDE file manager, what's the reliable way to reach an SMB share by name, and which tempting item should you avoid?

Now that smbtree and SMB1 browsing are obsolete, which command finds which devices offer SMB shares on the LAN, and what does its -S option add?

You need to list what a given host is sharing, including an anonymous listing without credentials. Which smbclient invocations do that?

smbclient can move files interactively without a permanent mount. Which four commands mirror an FTP session once you're connected to //server/share?

To work with an SMB share persistently as if it were a local folder, what mount type do you use, and which package must be installed?

You CIFS-mount a share as root but ordinary users can't read it, and permissions look wrong. Which mount options fix ownership and permissions, and what does nounix do?

You add a CIFS mount to /etc/fstab. Which option keeps an unavailable share from hanging boot, and how should credentials be handled?

A CIFS-mounted share's device suddenly goes offline and now the file manager and shutdown hang for minutes. What's the fix, and what's the catch?

Two of Samba's access-control models — share-level and workgroup security — are essentially obsolete. What does each do, and why does neither give real security?

How does Active Directory build on top of domain-level security, and which protocol does it use for authentication?

When planning a Samba deployment you choose between a central and a decentralized topology. What is the core backup trade-off between them?

You installed Samba on Fedora but systemctl start smbd fails and nothing shares. What are the distro gotchas around the Samba server package and service names?

In smb.conf's [global] section, what do the workgroup and server string parameters set, and what does %h expand to?

A distribution ships an smb.conf so padded with documentation comments it is unreadable. What is the clean way to strip it down, and what should you do first?

Beyond restricting Samba to certain interfaces, how do you permit or forbid specific individual hosts, and which option gives finer control?

On a dual-stack LAN you want Samba to speak IPv4 only for security. How do you force that, and why must you avoid host names in the config?

Someone sets syslog = 0 in smb.conf expecting to turn syslog off. What does it really do, and which two log files can smb.conf never relocate?

You turn on Samba/Linux password synchronization, but it only works when the ordinary user runs smbpasswd — running it as root silently skips the sync. Why?

The default [homes] section uses valid users = %S, and elsewhere you see %D%w%S. What do these percent variables expand to in a share definition?

Right-clicking a folder to share it from the GNOME or KDE file manager needs an extra package. Which one per desktop, and why can Fedora/RHEL users not do this at all?

No graphical sharing tool is available — how do you create a Samba user share straight from the terminal, and what two prerequisites still apply?

The GNOME Settings 'Shares' module offers to share Images, Music, Public, and Videos — but colleagues can't reach them over SMB. What is that module actually doing?

Your Linux desktop file manager doesn't 'see' the other machines on the LAN. Which service should be running, and how do you check and enable it?

Before a Linux box can act as an SMB client, the Samba client tools must be installed. Which packages provide them on Ubuntu versus Fedora?

In the GNOME/KDE network browser there's a tempting 'Windows Network' entry that the author warns you not to click. Why does it almost never work?

How do you tell smbclient to negotiate no higher than a given SMB protocol version, and when would you need that?

smbclient expects a share in Windows notation (backslash-separated). What goes wrong if you type single backslashes at the shell prompt, and what's the easy workaround?

File names with international characters show up garbled on a CIFS-mounted share. Which mount option fixes the display?

On Fedora/RHEL/SUSE the firewall blocks Samba by default. Which ports must open for a Samba server, and what's the quick way to do it?

On Windows, which service plays the NetBIOS name-server (NBNS) role, when is it mandatory rather than optional, and what can fill that role on Linux?

You want Unix-style network file sharing without any Microsoft heritage. What is the usual alternative to Samba, and what two constraints make it a poor fit for a mixed-OS home LAN?

A CIFS mount to an old NAS device or old Samba server fails with the defaults. Which two mount options coax it into working, and what defaults are they overriding?

You want an intermittently available CIFS share that does not mount at boot, yet an ordinary user can mount it on demand. Which two /etc/fstab options do this, and what bonus does GNOME add?

Beyond marking a share with guest ok = yes, what do guest only = yes and map to guest = never each change about guest access?