topic Re: console port problem in Operating System - Linux

console port problem

Chakravarthi — Mon, 08 Nov 2004 07:20:36 GMT

Hi,

i'm unable to access the linux server using serial port, but the with the same cable i can connet to other similar machine,

any tips to slove this problem
i tried init q -- no luck

thanks
chakri

Re: console port problem

HGN — Mon, 08 Nov 2004 08:42:35 GMT

Hi

There are few things you can test, try to kill the console proces and then do a init q, you can try to re-direct some data to the console
cat x > /dev/console
the x should contain something to see if that comes on the console.

RGds

HGN

Re: console port problem

Alexander Chuzhoy — Mon, 08 Nov 2004 08:57:33 GMT

edit /etc/inittab
append a line:
7:2345:respawn:/sbin/agetty ttyS0 9600

under 6:2345:respawn:/sbin/mingetty
and then execute init q

this will allow connection with baud rate 9600 on COM1 to your linux.
To be able to login as root-remember to append a line:
ttyS0
to /etc/securetty

Best regards

Re: console port problem

Chakravarthi — Mon, 08 Nov 2004 10:13:14 GMT

HI,

when i run the same command from the command line i get the followin error message

#strace -o /tmp/output /sbin/agetty -t 60 -L ttyS1 19200

i observe the following error message

ioctl(0, 0x5401, {B19200 -opost -isig -icanon -echo ...}) = 0
chown32(0xbffffa42, 0, 0) = 0
chmod("ttyS1", 0600) = 0
getpid() = 24595
ioctl(0, 0x5410, [24595]) = -1 ENOTTY (Inappropriate ioctl for dev
ice)
ioctl(0, 0x540b, 0x2) = 0
ioctl(0, 0x5402, {B19200 -opost -isig -icanon -echo ...}) = 0
fcntl64(0, 0x3, 0, 0xcbe) = 34818
fcntl64(0, 0x4, 0x8002, 0xbffffa42) = 0
alarm(60) = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGCHLD, NULL, {SIG_DFL}, 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
nanosleep({1, 0}, {1, 0}) = 0
ioctl(0, 0x540b, 0) = 0
uname({sys="Linux", node="nmhost01", ...}) = 0
write(1, "\r\n", 2) = 2
open("/etc/issue", O_RDONLY|O_LARGEFILE) = 3
ioctl(0, 0x5403, {B19200 opost -isig -icanon -echo ...}) = -1 EINTR (Interrupted
system call)
--- SIGALRM (Alarm clock) ---
+++ killed by SIGALRM +++

Re: console port problem

Sergejs Svitnevs — Mon, 08 Nov 2004 10:56:16 GMT

Check the BIOS settings (enable serial ports if there are disabled).
Regards,
Sergejs

Re: console port problem

Vitaly Karasik_1 — Mon, 08 Nov 2004 12:11:35 GMT

these articles may help you

http://www.vanemery.com/Linux/Serial/serial-console.html
http://www.tldp.org/HOWTO/Remote-Serial-Console-HOWTO/