Memory issue?

[Jim Reid]

>>>>> ">" == Riskable  <YouKnowWho at YouKnowWhat.com> writes:

    >> My server is hosting over 400,000 domains, but only has 64 megs
    >> of RAM.  When we purchased it, it was host to only about
    >> 100,000 domains.  Even with 400,000, named still only uses
    >> about 50% of the RAM (according to ps aux anyway).

This is odd. If you're using BIND8, each zone needs a zoneinfo struct
that occupies ~500 bytes (in round figures). On top of that memory is
needed for the resource records in each zone. So 400,000 zones will
mean your name server needs a minimum of 200Mbytes of RAM just to hold
the housekeeping data structures. This excludes the DNS data.

    >> Could these mysterious syntax errors be due to a lack of
    >> memory?

No. You get "out or memory" or "no VM" errors if your system is out of
memory. As seems likely from what you've said. Though this conflicts
with what you say ps says. You get syntax errors because something
can't be parsed. These errors could be in named.conf or in zone files:
you don't say which. I suppose it's possible that in extreme
circumstances, that if the OS has no available RAM some page/buffer
gets corrupted or zero-filled and that could cause syntax errors. But
there are probably lots of other errors in the logs - kernel warnings,
dying processes - if that happened.