I think there are multiple bugs in play here. My system-connections dir is a symlink within the same filesystem, and whenever I try to save a new connection I get the "settings plugin does not support adding connections" message.
Aug 18 17:11:08 workhorse4 NetworkManager[4092654]: <info> [1660857068.1365] audit: op="connection-add" pid=4124192 uid=1000 result="fail" reason="failure adding connection: settings plugin does not support adding connections" The symlink target dir has the same ownership/permissions as the original system-connections dir - 0755, root:root. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to network-manager in Ubuntu. https://bugs.launchpad.net/bugs/1913979 Title: misleading error messages when /etc/NetworkManager/system-connections is a cross-filesystem symlink Status in network-manager package in Ubuntu: Confirmed Bug description: If the /etc/NetworkManager/system-connections directory is a cross- filesystem symlink, activating connections will fail with the unrelated messages: * "failed to create file ...: Read-only file system" (TRACE level) * "failure adding connection: settings plugin does not support adding connections" (DEBUG level and above) * no error message (Gnome UI) I suspect moving the systems-connections directory onto a separate filesystem is not supported because network manager tries to atomically move a connection temp file into place and fails, but this is really hard to figure out since the error messages are completely unrelated. Versions: Ubuntu 20.10 network-manager 1.26.2-1ubuntu1 network-manager-gnome 1.18.0-1ubuntu2 How to reproduce: sudo mv /etc/NetworkManager/system-connections /some/other/mountpoint/system-connections sudo ln -s /some/other/mountpoint/system-connections /etc/NetworkManager/system-connections Then: * select any wifi network via the Gnome UI, or * connect to a wifi network via nmcli, or * connect to a wifi network via nmtui Symptoms: * "failed to create file ...: Read-only file system" (TRACE level, journalctl) * "failure adding connection: settings plugin does not support adding connections" (DEBUG level and above, journalctl and nmtui/nmcli output) * no error message (Gnome UI) Relevant sample logs: Feb 01 20:56:04 laptop NetworkManager[1368510]: <trace> [1612230964.4038] active-connection[0x56274f6f0a60]: creating Feb 01 20:56:04 laptop NetworkManager[1368510]: <debug> [1612230964.4039] active-connection[0x56274f6f0a60]: set device "wlp61s0" [0x56274f883f00] Feb 01 20:56:04 laptop NetworkManager[1368510]: <debug> [1612230964.4039] device[d62304f9da70d783] (wlp61s0): add_pending_action (1): 'activation-5' Feb 01 20:56:04 laptop NetworkManager[1368510]: <debug> [1612230964.4040] active-connection[0x56274f6f0a60]: constructed (NMActRequest, version-id 5, type managed) Feb 01 20:56:04 laptop NetworkManager[1368510]: <trace> [1612230964.4040] auth: call[37]: CheckAuthorization(org.freedesktop.NetworkManager.network-control), subject=unix-process[pid=1369566, uid=0, start=18908113] (succeeding for root) Feb 01 20:56:04 laptop NetworkManager[1368510]: <trace> [1612230964.4041] auth: call[37]: completed: authorized=1, challenge=0 (simulated) Feb 01 20:56:04 laptop NetworkManager[1368510]: <trace> [1612230964.4041] auth: call[38]: CheckAuthorization(org.freedesktop.NetworkManager.settings.modify.system), subject=unix-process[pid=1369566, uid=0, start=18908113] (succeeding for root) Feb 01 20:56:04 laptop NetworkManager[1368510]: <trace> [1612230964.4042] auth: call[38]: completed: authorized=1, challenge=0 (simulated) Feb 01 20:56:04 laptop NetworkManager[1368510]: <trace> [1612230964.4042] settings: add-connection: failed to add a4e6f563-eb2a-41ff-bc23-986ee3438ed9/'mywifi_2G': settings plugin does not support adding connections Feb 01 20:56:04 laptop NetworkManager[1368510]: <trace> [1612230964.4061] keyfile: commit: a4e6f563-eb2a-41ff-bc23-986ee3438ed9 (mywifi_2G) failed to add: error writing to file '/etc/NetworkManager/system-connections/mywifi_2G.nmconnection': failed to create file /etc/NetworkManager/system-connections/mywifi_2G.nmconnection.ZE5DY0: Read-only file system Feb 01 20:56:04 laptop NetworkManager[1368510]: <trace> [1612230964.4062] settings: add-connection: failed to add a4e6f563-eb2a-41ff-bc23-986ee3438ed9/'mywifi_2G': error writing to file '/etc/NetworkManager/system-connections/mywifi_2G.nmconnection': failed to create file /etc/NetworkManager/system-connections/mywifi_2G.nmconnection.ZE5DY0: Read-only file system Feb 01 20:56:04 laptop NetworkManager[1368510]: <debug> [1612230964.4062] active-connection[0x56274f6f0a60]: Failed to activate '(null)': failure adding connection: settings plugin does not support adding connections Feb 01 20:56:04 laptop NetworkManager[1368510]: <debug> [1612230964.4062] active-connection[0x56274f6f0a60]: set state deactivated (was unknown) Feb 01 20:56:04 laptop NetworkManager[1368510]: <debug> [1612230964.4063] active-connection[0x56274f6f0a60]: check-master-ready: not signalling (state deactivated, no master) Feb 01 20:56:04 laptop NetworkManager[1368510]: <debug> [1612230964.4063] device[d62304f9da70d783] (wlp61s0): remove_pending_action (0): 'activation-5' Feb 01 20:56:04 laptop NetworkManager[1368510]: <debug> [1612230964.4066] audit: socket created Feb 01 20:56:04 laptop NetworkManager[1368510]: <debug> [1612230964.4067] create NMAuditManager singleton (a031d34f795a73ab) Feb 01 20:56:04 laptop NetworkManager[1368510]: <info> [1612230964.4069] audit: op="connection-add-activate" pid=1369566 uid=0 result="fail" reason="failure adding connection: settings plugin does not support adding connections" Feb 01 20:56:04 laptop NetworkManager[1368510]: <debug> [1612230964.4069] active-connection[0x56274f6f0a60]: disposing To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1913979/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp