Hangs up during reboot/shutdown

[Tapas Ranjan]

>Tapas Ranjan wrote:
>
>>Hi :
>>	Sometimes the pc hangs up during reboot. When the network is poor,
>>the eth1 seems to be freezed and even typing "ifconfig" also hangs up.
>>
>>
>That's not normal at all.  "ifconfig" should never hang the system
>unless it's actually running something that's sucking down the CPU.
>Before you do "ifconfig" try "ps -ax" or "top" and see how busy the CPU
>is.

What I meant here is, after network freezes, typing "ifconfig" doesn't
respond at all. Nothing ( service pcmcia, network ) works to restart
the network that time and when I reboot/shutdown the system to solve the 
network issue it hangs up at various points like shutting down 
"iptables" or "lo". This may be pointing that, while checking "iptables"
during shutdown, doesn't get any information because the network is 
freezed and the cursor just stays there blinking.

>
>
>> So rebooting the system due to those problem hangs up the system at 
>"shutting down loopback interfaces" or at "iptables". 
>
>
>The loopback interface is "lo" and is a purely software construct.
>There is no hardware involved in that at all.  Shutting it down should
>NEVER hang the system.
>
>
>>    This happens once in 6-7 reboots or so. 
>
>
>I really suspect you have a runaway process.  "top" or "ps -ax" or
>"uptime" should give you some clues

	What I remeber, the day after I ran "apache" and 
"ez-ipupdate" on my laptop, these problems started. I think this is what
causing  trouble. Now I have stopped it for few days and will check the 
happenings.

>
>
>    I am using FC2 with 2.6.8-1.521 ( upgraded from 2.6.5-1.358
>    through "yum" ). Help from experts is needed. 
>
>
>I use that kernel all the time with no issues at all.
>
>As near as I can tell, you have several possible issues:
>
>	1. A runaway process
>	2. Your machine has been hacked and is doing evil things
>	3. Faulty hardware or memory
>
>
>The "ps -ax" and "top" commands will show you what's running on your
>machine (unless you've been had a rootkit hack), so that's the first
>thing to check.  You should also try to run "chkrootkit" (do a google
>search for it, then download and run it) to check for a rootkit hack.
>

Though there is hardly any chance that the system can be hacked, since 
it's under a firewall and noone can see it from outside, I will give
the above a try. Here I want to mention, a "gkrellm" is always running on
the screen which shows all the necessary information and I haven't noticed
any suspicious stuff.

>
>You can test your memory by booting off FC2's first CD and entering
>"memcheck86" at the "boot:" prompt.  If it shows bad memory, shut the
>machine down, open it up and reseat ALL of your cards (memory, PCI
>cards, and the CPU if possible).  You'd be amazed at how many "cranky"
>machines get fixed just by reseating the cards.  Run the memtest86 again
>and see if the problem has gone away.  If so, voila!  If not, then
>you probably do have bad RAM.  And remember, Linux flogs your RAM a lot
>harder than Windows does.  I've seen many systems with bad RAM run
>Windows but not Linux.

	Sure, will try rhis. Thanks a lot.

	---Tapas