What kind of a crash is this ? (kernel ? userland ?)

[Dan Nelson]

In the last episode (Jan 31), Joe Schmoe said:
> I have become familiar with certain FreeBSD crashes - namely, I can
> tell the difference between the kernel crashing, and the userland
> crashing.
>  
> If the machine is down, but I can still ping it, then the userland
> has crashed - the kernel is still running, which is why it responds
> to pings.

"userland" doesn't crash (except maybe if you break libc.so).  Rather,
one binary most likely is not running.  You may be able to telnet in if
ssh is not running, for example.
  
> But if it crashes and just reboots itself, then the kernel has
> crashed.  Oversimplified I know, but I am leading up to:
>  
> What kind of a crash is it if:
>  
> I can ssh to the system, it gives me the BSD copyright and the uname
> message, but never ever gives me a prompt.  What is going on in this
> scenario ?  What kind of things have you seen that cause a crash like
> this ?

Hit ^T and find out what command on the remote side is currently
running, and what it's waiting on.  Could be DNS, a remote NFS server
not responding, local disk problems, etc.

-- 
	Dan Nelson
	dnelson at allantgroup.com