innd lockup

[Brian Kantor]

>
>> I am currently experiencing a problem where innd locks up completely at
>> random times.  In this state not even a kill -9 will do it and I have to
>> reboot.
>
I missed which operating system you're running.

I have encountered this problem as well, but I believe it is a flaw in
the OS I'm using (BSD/OS 4.1) which may only be triggered by a very busy
system.  I would not be surprised to hear that the same thing is occuring
in other 4.4BSD-derived OSs.

When it occurs, INND and other processes are stuck in 'inode' wait,
which is a highly unusual place to see a process stuck.  No kill will
release that, necessitating a reboot.  In some cases, the reboot will
fail (usually the last message on the console is 'syncing filesystems'),
and the system never shuts down, necessitating a hardware reboot.

I don't think it's INN that's doing it, as our Cyrus mail server has
done this as well.  My suspicions lie in the area of memmapped file
I/O, but that's just a guess.  I've gone no further for lack of time.
Perhaps someone else can.
	- Brian