Arch Linux

zorggy

Member

Registered: 2013-05-30

Posts: 26

[SOLVED] Two difficulties with systemd

Hello,

I have a two difficulties with systemd.

Startup:
According to the 'systemd-analyse blame' command, each service start in less than 200ms except dhcpcd: dhcpcd@eno1.service = 12s. Is it usual with Gigabit Ethernet to get a so slow network startup?

Kerberos:
My logging in process is local, but I added the pam-krb5 package (from AUR) to get a remote Kerberos authentication at the same time. Unfortunately it does not work every time: It's good if I wait few seconds before logging in and I suppose it is due to the slow network startup. So I would like to run the Display Manager (sddm) only after network is up. To configure it, I copied /usr/lib/systemd/system/sddm.service to /etc/systemd/system/sddm.service and I modified the copy:

[Unit]
Description=Simple Desktop Display Manager
Documentation=man:sddm(1) man:sddm.conf(5)
Conflicts=getty@tty1.service
Wants=network-online.target   ### line added
After=systemd-user-sessions.service getty@tty1.service plymouth-quit.service network-online.target ### last target added

[Service]
ExecStart=/usr/bin/sddm
Restart=always
#PrivateTmp=yes

[Install]
Alias=display-manager.service

But there is no change: sddm starts straight on without waiting for the network. What did I do wrong?

Last edited by zorggy (2015-01-16 21:10:04)

Awebb

Member

Registered: 2010-05-06

Posts: 6,688

Re: [SOLVED] Two difficulties with systemd

Startup: Try ditching dhcpcd and replacing it with systemd-networkd. If it still sucks, your network might have an issue.

Another thing: Disable the dhcpcd service and run it manually after the system is up and running. Then run blame. Is it faster now? If yes, you have the same problem I have, something blocks dhcpcd in relatively early boot. Ditching it for systemd-networkd will not fix this entirely, but reduce it from 12s to 1s (or so, on my setup).

zorggy

Member

Registered: 2013-05-30

Posts: 26

Re: [SOLVED] Two difficulties with systemd

So I moved to systemd-networkd and... it did not work as I did not configure at all the service. Finally there is only one little file to create, /etc/systemd/network/dhcp.network:

[Match]                                                                                                                                                             
Name=en*                                                                                                                                                            
                                                                                                                                                                    
[Network]                                                                                                                                                           
DHCP=v4

and it worked. After disabling dhcpcd@eno1 and enabling the new service and a reboot, I get only 34ms to start the service. Wow, fantastic! Thank you very much, Awebb.

Finally I don't need to delay the Display Manager, but if somebody can point out what I did wrong, I would learn another thing.

bstaletic

Member

Registered: 2014-02-02

Posts: 658

Re: [SOLVED] Two difficulties with systemd

You did nothing wrong, dhcpcd is just slow. Don't know about dhclient. Networkd is the fastest.

Remember to mark thread as solved.

---

My dotfiles

Awebb

Member

Registered: 2010-05-06

Posts: 6,688

Re: [SOLVED] Two difficulties with systemd

You did nothing wrong. If you go through my posts of the past few days (search for dhcpcd), you will find that I recently came across the same thing.

EDIT: https://bbs.archlinux.org/viewtopic.php?id=192186

Remember to mark thread as solved.

Old Talaxian proverb: He, who has second question, must count the dots on his hand first.

Last edited by Awebb (2015-01-16 16:33:31)

gaelic

Member

Registered: 2010-08-01

Posts: 126

Re: [SOLVED] Two difficulties with systemd

My guess is that dhcpcd tries to get also a v6 Adress but runs into a timeout ...

gnubeest

Member

Registered: 2014-04-19

Posts: 8

Re: [SOLVED] Two difficulties with systemd

Technically the answer is to add

noarp

to your dhcpcd config. It will significantly improve the time it takes to get an IP.

But yes, networkd.