Windows Shares (SMB)
3 minute read.
SMB (also known as CIFS) is the native file-sharing system in Windows. SMB shares can connect to most operating systems, including Windows, Mac OS, and Linux. TrueNAS can use SMB to share files among single or multiple users or devices.
SMB supports a wide range of permissions, security settings, and advanced permissions (ACLs) on Windows and other systems, as well as Windows Alternate Streams and Extended Metadata. SMB is suitable to manage and administer large or small pools of data.
TrueNAS uses Samba to provide SMB services. The SMB protocol has multiple versions. During the SMB session negotiation, a typical SMB client can negotiate the highest supported SMB protocol. Industry-wide, SMB1 protocol (sometimes referred to as NT1) use is deprecated for security reasons.
As of TrueNAS 22.12 (Bluefin) and later, TrueNAS does not support SMB client operating systems that are labeled by their vendor as End of Life or End of Support. This means MS-DOS (including Windows 98) clients, among others, cannot connect to TrueNAS SMB servers.
The upstream Samba project that TrueNAS uses for SMB features notes in the 4.11 release that the SMB1 protocol is deprecated and warns portions of the protocol might be further removed in future releases. Administrators should work to phase out any clients using the SMB1 protocol from their environments.
However, most SMB clients support SMB 2 or 3 protocols even when they are not the default.
Legacy SMB clients rely on NetBIOS name resolution to discover SMB servers on a network. TrueNAS disables the NetBIOS name server (nmbd) by default. Enable it on the Network > Global Settings screen if this functionality is required.
Mac OS clients use mDNS to discover SMB servers present on the network. TrueNAS enables the mDNS server (avahi) by default.
Windows clients use WS-Discovery to discover the presence of an SMB server. You can disable network discovery by default depending on the Windows client version.
Discoverability through broadcast protocols is a convenience feature and is not required to access an SMB server.