Boot Hangs When Ethernet Cable Plugged In

[Peter G.]

I have recently started using the ethernet instead of wifi. I have not disabled the wifi, but I leave the ethernet cable inserted. Recently, I noticed that I was unable to start the computer. I thought it was a faulty F37 testing kernel, so I tried the previous kernel. Same thing. For some reason, I thought the only thing different is that I now have the ethernet hooked up, so I pulled the plug and tried to boot. Everything went fine.

How come I cannot boot the computer with the ethernet cable plugged in?

[George N. White III]

On Sat, Sep 24, 2022 at 11:45 AM Peter G.  wrote:

I have recently started using the ethernet instead of wifi. I have not
> disabled

the wifi, but I leave the ethernet cable inserted. Recently, I noticed that
> I was

unable to start the computer. I thought it was a faulty F37 testing kernel,
> so I

tried the previous kernel. Same thing. For some reason, I thought the only

thing different is that I now have the ethernet hooked up, so I pulled the
> plug

and tried to boot. Everything went fine.
> How come I cannot boot the computer with the ethernet cable plugged in?

I recently did the reverse (system was running reliably on ethernet, but
switched to wifi and then didn't boot after an update was applied).
Journalctl
revealed that the update had lost the ability to mount the (hfsplus format)
EFI
partition.  After reinstalling the update, wifi is working.

Use journalctl to collect evidence.  It may also be useful to search across
other
distros (particularly arch) for similar problems with your ethernet
hardware.

[Peter G.]

I had a look at journalctl. I am not very adept at it or understanding what it says, but I found some curious things just before it hangs:

Sep 23 21:13:19 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net systemd[1]: Started [e-mail] - User Manager for UID 988.
Sep 23 21:13:19 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 >
Sep 23 21:13:19 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net systemd[1]: Started session-c1.scope - Session c1 of User sddm.
Sep 23 21:13:19 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit[1281]: USER_START pid=1281 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:xdm_t:s>
Sep 23 21:13:19 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net sddm-helper[1281]: Starting X11 session: "" "/usr/bin/sddm-greeter --socket /tmp/sddm-:0-jEzEIX --th>
Sep 23 21:13:19 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net sddm-greeter[1297]: could not connect to display :0
Sep 23 21:13:19 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit[1297]: ANOM_ABEND auid=4294967295 uid=988 gid=986 ses=4294967295 subj=system_u:system_r:xdm_t:>
Sep 23 21:13:19 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net sddm-greeter[1297]: Could not load the Qt platform plugin "xcb" in "" even though it was found.
Sep 23 21:13:19 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net sddm-greeter[1297]: This application failed to start because no Qt platform plugin could be initiali>

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, >
Sep 23 21:13:19 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net systemd[1]: Created slice system-systemd\x2dcoredump.slice - Slice /system/systemd-coredump.
Sep 23 21:13:19 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit: BPF prog-id=79 op=LOAD
Sep 23 21:13:19 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit: BPF prog-id=80 op=LOAD
Sep 23 21:13:19 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit: BPF prog-id=81 op=LOAD
Sep 23 21:13:19 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net systemd[1]: Started [e-mail] - Process Core Dump (PID 1298/UID 0).

I am not sure what to make of it, but it appears that when the ethernet is used, sddm wants to start plasma in X11 mode?

As I mentioned, when I have the ethernet cable pulled out and the wifi on only, then it works. I haven't tried leaving ethernet plugged in but having wifi set to off (and manually start it once logged in only when required).

[Peter G.]

Reply #2

Ok, for curiosity, i disabled wifi, set it to be started manually only, left ethernet to be started automatically. I shut down the computer, leaving the ethernet cable plugged in and started up the computer. journalctl reports:

Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net systemd[1]: Started [e-mail] - User Manager for UID 988.
Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=user@988 comm="systemd" exe="/usr/lib/systemd/systemd" hostname>
Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net systemd[1]: Started session-c1.scope - Session c1 of User sddm.
Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit[1282]: USER_START pid=1282 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:xdm_t:s0-s0:c0.c1023 msg='op=PAM:session_open grantors=pam_unix,pam_systemd acct>
Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net sddm-helper[1282]: Starting X11 session: "" "/usr/bin/sddm-greeter --socket /tmp/sddm-:0-DVndsw --theme /usr/share/sddm/themes/01-breeze-fedora"
Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net sddm-greeter[1298]: could not connect to display :0
Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit[1298]: ANOM_ABEND auid=4294967295 uid=988 gid=986 ses=4294967295 subj=system_u:system_r:xdm_t:s0-s0:c0.c1023 pid=1298 comm="sddm-greeter" exe="/usr/bin/sddm-greeter" s>
Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net sddm-greeter[1298]: Could not load the Qt platform plugin "xcb" in "" even though it was found.
Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net sddm-greeter[1298]: This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx>
Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net systemd[1]: Created slice system-systemd\x2dcoredump.slice - Slice /system/systemd-coredump.
Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit: BPF prog-id=79 op=LOAD
Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit: BPF prog-id=80 op=LOAD
Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit: BPF prog-id=81 op=LOAD
Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=systemd-coredump@0-1299-0 comm="systemd" exe="/usr/lib/systemd/>
Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net systemd[1]: Started [e-mail] - Process Core Dump (PID 1299/UID 0).
Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net [1302]: [156B blob data]
Sep 24 10:45:51 node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net systemd-coredump[1301]: [🡕] Process 1298 (sddm-greeter) of user 988 dumped core.

As far as I can tell, it does the same thing. SDDM will not start, so the system hangs, does not present a login screen and does a core dump.

So, basically, I need to keep the ethernet cable unplugged until logged in. The wifi can remain automatic or manual, makes no difference.

Ideas on this?