Linux – Prevent kernel messages from appearing in dmesg

dmesg displays what is in the kernel buffer, whereas logger is for syslogd. I think if you want to print things into the kernel buffer you will need to create a driver that uses the printk() kernel function. If you just want it in /var/log/messages, then with a "normal" setup I think what you have done with logger is already fine.

The most basic example of a driver with printk() would be:

hello.c:

#include <linux/module.h>
#include <linux/kernel.h>

int init_module(void)
{
    printk(KERN_INFO "Hello world\n");
    return 0;
}

void cleanup_module(void)
{
    printk(KERN_INFO "Goodbye world\n");

}

Makefile:

obj-m += hello.o

all:
    make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules

Then:

$ make
$ sudo insmod hello.ko
$ dmesg | tail -n1
 [7089996.746366] Hello world

http://tldp.org/LDP/lkmpg/2.6/html/lkmpg.html#AEN121 for more...

You need to set up remote syslog logging and the netconsole modules so that when it panics it will dump the panic over UDP to your remote machine. This will work as long as the network card isn't involved in the panic :) See http://www.mjmwired.net/kernel/Documentation/networking/netconsole.txt (which is from the kernel source) for details or http://www.cyberciti.biz/tips/linux-netconsole-log-management-tutorial.html for a tutorial/howto.