Today Bind has started to go strange on us. We're running Bind 4.9.4PL1
under NetBSD 1.1. When we 'kill -HUP' the named, it fails to reload the
primary zones, saying 'Too many open files'. It also seems to be doing
this sometimes for zone transfers. Does anybody have any idea why it
does this (it surely can't be *really* running out of files, it only
needs about 4 sockets and, err, no files)? Killing the named completely
and restarting it doesn't help, rebooting the machine does.

While we're on the subject of open files, how is the per-process
maximum specified? I think the relevant value is '_SC_OPEN_MAX'
(man sysconf says this is maximum number of open files per
*user id*, this isn't right is it?) This appears to be related to
'ulimit -n' (which apparently any user can set to kern.maxfiles and
hence perform a trivial denial-of-service attack?). Is there a limit
to what _SC_OPEN_MAX or kern.maxfiles can be set to, without kernel
recompilation?

Cheers


Jon
____
\  //    Jon Ribbens    // 10MB virtual-hosted // www.oaktree.co.uk
 \// jon@oaktree.co.uk // web space for 49UKP //