CentOS 7.6 serial console probelm

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vcba79
Posts: 31
Joined: 2015/12/21 09:36:06

CentOS 7.6 serial console probelm

Post by vcba79 » 2019/06/01 11:44:01

Hi, all

I am runn CentOS 7.6 and has getty@ttyS0 service enabled and running

getty@ttyS0.service - Getty on ttyS0
Loaded: loaded (/usr/lib/systemd/system/getty@.service; enabled; vendor preset: enabled)
Active: active (running) since Fri 2019-05-31 21:23:57 CST; 22h ago
Docs: man:agetty(8)
man:systemd-getty-generator(8)
http://0pointer.de/blog/projects/serial-console.html
Main PID: 16605 (agetty)
CGroup: /system.slice/system-getty.slice/getty@ttyS0.service
└─16605 /sbin/agetty --noclear ttyS0 vt220

But I can not connect to this machine with null modem cable. This cable and putty client can connect
to other box without any problem and I tried every baud rate combination. Is there any
thing I should do to fix this?

dunch
Posts: 66
Joined: 2018/11/07 13:48:53
Location: Yorkshire

Re: CentOS 7.6 serial console probelm

Post by dunch » 2019/06/03 10:40:43

You need to add console=ttyS0 to the kernel command line.

vcba79
Posts: 31
Joined: 2015/12/21 09:36:06

Re: CentOS 7.6 serial console probelm

Post by vcba79 » 2019/06/05 01:13:45

I add console=ttyS0 to the kernel command line and see following process running

4344 ? Ss 0:00 /sbin/agetty --keep-baud 115200,38400,9600 ttyS0 vt220

But putty connection still no login prompt

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