I can confirm this fixes the issue for me, too, using network-manager 1.44.2-1ubuntu1.2 from mantic-proposed.
$ sudo apt install -t mantic-proposed network-manager [...] $ LC_ALL=C apt list -i network-manager Listing... Done network-manager/mantic-proposed,now 1.44.2-1ubuntu1.2 amd64 [installed] $ nmcli con add type dummy connection.interface-name dummy0 $ sudo cat /etc/netplan/90-NM-4189c63a-ecee-4a39-90f3-fffad2b96d0b.yaml network: version: 2 dummy-devices: NM-4189c63a-ecee-4a39-90f3-fffad2b96d0b: renderer: NetworkManager networkmanager: uuid: "4189c63a-ecee-4a39-90f3-fffad2b96d0b" name: "dummy-dummy0" passthrough: connection.interface-name: "dummy0" dummy._: "" ipv4.method: "disabled" ipv6.addr-gen-mode: "default" ipv6.method: "disabled" ipv6.ip6-privacy: "-1" proxy._: "" $ nmcli d show dummy0 GENERAL.DEVICE: dummy0 GENERAL.TYPE: dummy GENERAL.HWADDR: 32:89:DC:E0:74:2F GENERAL.MTU: 1500 GENERAL.STATE: 100 (verbunden) GENERAL.CONNECTION: dummy-dummy0 GENERAL.CON-PATH: /org/freedesktop/NetworkManager/ActiveConnection/10 IP4.GATEWAY: -- IP6.GATEWAY: -- $ nmcli con del dummy-dummy0 $ LC_ALL=C nmcli d show dummy0 Error: Device 'dummy0' not found. $ sudo LC_ALL=C cat /etc/netplan/90-NM-4189c63a-ecee-4a39-90f3-fffad2b96d0b.yaml cat: /etc/netplan/90-NM-4189c63a-ecee-4a39-90f3-fffad2b96d0b.yaml: No such file or directory $ journalctl -u NetworkManager -e # I cannot spot any errors in here ** Tags removed: verification-needed-mantic ** Tags added: verification-done-mantic -- 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/2040153 Title: Network Manager will not remove Netplan YAMLs when connections are deleted Status in netplan.io package in Ubuntu: Triaged Status in network-manager package in Ubuntu: In Progress Status in netplan.io source package in Mantic: Invalid Status in network-manager source package in Mantic: Fix Committed Bug description: [ Impact ] Desktop users, or any users with YAML files in /usr/lib/netplan, can't delete Network Manager connections persistently. That means that, when the connection is deliberately deleted by the user, it will re-appear when the system is rebooted or netplan apply is executed. This is happening because the systemd service unit is setting the property "ProtectSystem" to true. Because of that, /usr is being presented to the Network Manager daemon as read-only. When connections are deleted, libnetplan will try to open its YAML files with writing permissions and will fail for files from /usr/lib/netplan. Even if the user hasn't added any files there manually, the file /usr/lib/netplan/00-network-manager-all.yaml will be installed by the package ubuntu-settings. This issue is fixed by allow-listing /usr/lib/netplan with ReadWritePaths=/usr/lib/netplan in systemd so the Network Manager's daemon will be able to write to that directory. This upload also improves the autopkgtests related to Netplan. Network Manager will be started by systemd, which ensures we are testing in the same environment conditions used by a desktop installation. It also adds a few more instances of connections deletions so we can test a bit more that YAML files are being removed. It also adds all the dependencies required by the test script (which sadly was causing the nm_netplan.py tests to be skipped). [ Test Plan ] Launch a new Mantic VM: $ lxc launch ubuntu:mantic --vm Install network-manager and ubuntu-settings: # apt install network-manager ubuntu-settings Run Netplan # netplan apply Create a dummy connection via nmcli: # nmcli con add type dummy connection.interface-name dummy0 Check a new YAML will be created in /etc/netplan Delete the connection with nmcli # nmcli con del dummy-dummy0 Check the YAML WAS NOT removed from /etc/netplan You will see the error below in the NetworkManager's journal netplan_delete_connection: Cannot write output state: Read-only file system Add the PPA containing the fix and run the same test described above # add-apt-repository ppa:danilogondolfo/network-manager # apt update # apt upgrade Check that the YAML will be created when the connection is added and deleted and the connection is removed. [ Where problems could occur ] As the only change is a relaxation of the restrictions applied by systemd on the environment where Network Manager runs, we are not expecting any regression. As for the changes in the autopkgtest related to Netplan, they are passing on all architectures. Autopkgtests amd64 - https://autopkgtest.ubuntu.com/results/autopkgtest-mantic-danilogondolfo-network-manager/mantic/amd64/n/network-manager/20231023_175203_b2798@/log.gz ppc64 - https://autopkgtest.ubuntu.com/results/autopkgtest-mantic-danilogondolfo-network-manager/mantic/ppc64el/n/network-manager/20231023_182332_f0497@/log.gz s390x - https://autopkgtest.ubuntu.com/results/autopkgtest-mantic-danilogondolfo-network-manager/mantic/s390x/n/network-manager/20231023_190810_ced8d@/log.gz arm64 - https://autopkgtest.ubuntu.com/results/autopkgtest-mantic-danilogondolfo-network-manager/mantic/arm64/n/network-manager/20231024_084542_ac017@/log.gz armhf - https://autopkgtest.ubuntu.com/results/autopkgtest-mantic-danilogondolfo-network-manager/mantic/armhf/n/network-manager/20231024_083545_ac017@/log.gz [ Other Info ] --- Original description --- When a connection is deleted using any NM facility, libnetplan is failing to delete the YAML file. Because of that, the connection will be recreated when "netplan generate" runs again. This is probably being caused by a combination of two things. First, the NM's systemd unit has this setting "ProtectSystem=true", which will mount /usr as read-only for NM. Second, we migrated the default "00-network-manager-all.yaml" file to, /usr/lib/netplan recently [1]. When libnetplan tries to open this file for writing, the open system fails with EROFS: --- 22517 openat(AT_FDCWD, "/lib/netplan/00-network-manager-all.yaml", O_WRONLY|O_CREAT|O_TRUNC, 0600) = -1 EROFS (Read-only file system) 22517 write(2, "netplan_delete_connection: Canno"..., 76) = 76 --- [1] - https://launchpad.net/ubuntu/+source/ubuntu-settings/23.10.1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/netplan.io/+bug/2040153/+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