We have a computer with RedHat linux 8.0. But it failed to boot and crashed during the bootup process

twice during last month.

We had to reinstall redhat both times. The computer has Apache server with php and Mysql 3 running.
We also use j2sdk1.4 in that computer. we have a small Java program which uses the MySql database.

What can be the possible causes of system crashing during bootup. Can it be a problem with LILO or

something else.

Can you also advice me on ways that I can restore a Redhat system that fails to boot without reinstalling.

You need to be a little more specific in what you mean by fails to boot.
What exactly happens? When does it fail?

Hi brentos,

I really do not know much about linux. I am still trying to learn linux. So I really do not know exactly why the system fails.

Is it possible for a Java program(Running on JVM 1.4) accessing Mysql database to crash and make a linux system unbootable.

Thanks a lot,
Chamal.

Generally, no, unless you've done something silly like running a lot of code that doesn't need priviliges as root, and that code proceeds (by accident or design) to do the equivalent of rm -rf / (or hoses some other critical system files). Unfortunately, we really need a few details to figure out what happened. Please try to boot the machine, and write down the last few lines of output before it fails. Even if you don't understand what they mean, someone here probably will.

Hi guys,

I really can't remember the exact output I got. I can't get it again because we reinstalled redhat again.

Other symptom of this problem is that the root password got changed last time. I am sure that I remember the password. But when I type it the computer does not accept it.

Now it has happened again. We reinstalled linux on last Friday and everything worked fine. But when we try to login on Monday(Saturday and Sunday were holidays) the computer says that root password is incorrect.

Can this be a remote attack.

Plz help me to solve this problem.

THanks a lot,
Chamal.

Are you using the same root password everytime you are re-install Redhat? Try a different password. Yes, it could be some guy screwing your machine over. I suggest changing the root password and installing AIDE or tripwire to see if anything has been tampered with.

Also, make a note of the error messages you get when you boot up the comp.

-twantrd

pay attention at what runlevel is being used to boot your system.. check the number of the system run level... for example if you configure Slackware 10 to start on run level "6"
it will keep rebooting and rebootiung at every start-up!
But that number changes from distro to distro...

Does that runlevel (level 6) really change from distro to distro? I haven't used all the distros but I have touched SuSE, Debian, Redhat and that runlevel is pretty universal (at least on linux) I thought.

-twantrd

OK, I think the run level 6 does not change, twantrd..

but for example in Slackware:
3 is for the console.
4 is for the GUI.

and in Conectiva:
3 is for the console as well.
5 is for the GUI.

But, anyway, the file /etc/inittab is very well commented, and all the runlevels are listed there, as well as the recommendations for each one...

Joannes

Hi guys,

Thanks a lot for your replies.

What is meant by runlevel. Does it affect the password.

Thanks a lot,
Chamal.

no it doesn't affect the password.

The run level specifies the way your system boots up...

as described above, each number runs a diferent run level...

take a look at the file /etc/inittab to see what the possible runlevels are,

actually I'm not sure it could be your problem, as you said it just fails after you reboot the machine.. but anyway, just take a look at the file