Strange system freezes - Help!

[Ben Russo]

Erik Williamson wrote:

>I've got a machine with the following description:
>Dell Precision 530
>Fully patched fedora
>Dual P4
>Alteon Gigabit nic
>Services running:  sshd, vsftpd, apache
>
>Periodically, it goes (mostly) dead.  It looks like this:
>I can ping it.
>I can nmap it, and the services are all detected
>I cannot connect to any of the servers via a client (ie, ssh, ncftp, moz)
>I can telnet to the appropriate ports, and get connected. (I forget how to 
>make an http server spew to a telnet client, but I've done it before)
>Both the terminal (through kvm) and console (serial, through to a 
>concentrator on another machine) are dead in the water.
>If I unplug the fibre to the nic, the console + terminal report this.  
>same for when I replug it in.  Nothing happens with usb devices (just 
>trying to see about waking it up)
>
>It's last uptime was a day and a half.  this is the third time it's 
>happened.  I'm about to do hardware diagnostics on it, but am 
>wondering if anyone has any idea about what else I should look at.
>
>  
>
Hmmmm,  I would try (just as a test) replacing the Alteon Gigabit NIC 
with something
else and see if the freeze problem goes away.
You might also go into the BIOS and disable any devices you are not using
(this can cause the Interrupts to be re-arranged, so in case there was 
any conflict
it might be resolved).
Check /proc/interrupts

Try booting from CD #1 of the Fedora Beta 3 (or the Fedora Core 1 final 
release)
At the boot prompt try typing "memtest86"
and let that run overnight.