Hi all:
I just experienced the weirdest thing... or at least something that I
certainly didn't expect to see in an Unix box. Let me explain:
1) I have a Red Hat Linux 6.2 as a mail server, with the 2.2.17 kernel
and qmail 1.03. It's been working great for months, as one could expect.
2) Today, for reasons unrelated, I decide to stop all outgoing mail. I
stop qmail-send and then to a "killall qmail-remote". Everything fine,
the box is still working. (Note that I did not stop incoming mail, nor
POP access).
3) Some minutes later I decide to restart qmail again. qmail-qstat says
that there are around 250 messages in the queue, of which 140 (more or
less) are unprocessed. I restart qmail and everything goes fine... for a
few seconds, after which the box becomes unresponsive.
4) I go to the console, and see it filling up with the following
message: "VM: do_try_to_free_pages_failed_for qmail-remote" (the wording
may not be exact, though). I try to log in, but the machine isn't
responding at all (just printing this message as fast as it can), and am
finally forced to push the button and reboot (ouch).
Now, what I'd like to know is: what happened? I certainly didn't expect
to see this in two pieces of software as robust as qmail and Linux, and
I usually perform the above operation (stop outgoing mail, do whatever,
start qmail-send again) without any problems. I don't think that a queue
of just 250 messages is enough to make either qmail or Linux barf. So...
what happened?
Paulo Jan.
DDnet.
