YaST versus direct configuration on SUSE: what still runs from the command line, and the wicked/NetworkManager split

What it is

YaST is SUSE's system configuration tool, and on a headless SLES 15 SP6 host it runs in an ncurses text interface rather than only as a GUI. sudo yast2 launches the full menu-driven text interface; yast --list (or yast -l) prints the names of all modules installed for the current YaST front end; sudo yast <module_name> starts one module's interactive interface directly. For scripts, modules with command-line support accept subcommands, listed by sudo yast <module_name> help. Not every module ships command-line support, and the set of modules differs between the ncurses and GUI builds, so a module seen in one may be absent from the other.

Underneath most YaST modules are the same files an administrator could edit directly: /etc/sysconfig/network/ifcfg-* for interfaces, /etc/zypp/repos.d/*.repo for repositories, and so on. For agents, this means two equally valid paths exist for the same setting — through a YaST module's non-interactive command form, or by editing the backing file and applying it with the relevant reload command (wicked ifreload, systemctl reload sshd, etc.).

Why it matters

SUSE's own documentation is explicit that NetworkManager "is only supported by SUSE for desktop workloads with SLED or the Workstation extension," and that all server certifications are done with wicked as the network configuration tool — meaning a certified deployment expects wicked to own interface configuration, and switching to NetworkManager on a server can invalidate that certification. Editing ifcfg-* files by hand while wicked is active is compatible; editing them while NetworkManager is controlling the same interface is not, because NetworkManager keeps its own connection profiles.

How to apply

• Check which service manages networking before editing anything: systemctl is-active NetworkManager and systemctl is-active wicked; only one should be the active network service.
• To switch, use YaST's Network Settings module (Global Options tab, "Network Setup Method" field): choose "User Controlled with NetworkManager" or "Controlled by wicked". Switching the network service can interrupt connectivity, so do it from a console rather than over an SSH session that depends on the interface being reconfigured.
• For scripted configuration on a server, prefer editing /etc/sysconfig/network/ifcfg-* under wicked, matching what SUSE tests server images against.
• Use yast --list in a new session to discover what is actually available before assuming a module exists.

Pitfalls

• Installing NetworkManager on a server image "because it's more familiar" without checking that no other tooling (firewalld zones tied to wicked interface names, monitoring) assumes wicked.
• Assuming every setting has a YaST command-line equivalent; when it does not, edit the backing file directly and reload the owning service.
• Applying this to the 16 generation: SLES 16 and openSUSE Leap 16 no longer ship wicked and move administration from YaST to other tools, so this article covers the 15 line; verify on the release in use.