One of my latest patches (d8db0f9690) created support for setting
the limit for the maximum of opened files by qemu user. However,
since libvirtd keeps one FD opened per domain (well, for qemu at least)
it will likely hit this limit on huge scenarios.
To install it, disable libvirtd sysv initscript:
chkconfig libvirtd off
service libvirtd stop
and enable libvirtd upstart job:
cp /usr/share/doc/libvirt-*/libvirtd.upstart \
/etc/init/libvirtd.conf
initctl reload-configuration
initctl start libvirtd
Test:
initctl status libvirtd
libvirtd start/running, process 3929
killall -9 libvirtd
initctl status libvirtd
libvirtd start/running, process 4047
I looked into the possibility to use the upstart script from Ubuntu or
at least getting inspiration from it but that's not possible. "expect
daemon" is a nice thing but it only works if the process is defined with
exec stanza instead of script ... no script. Unfortunately, with exec
stanza environment variables can only be set within upstart script
(i.e., configuration in /etc/sysconfig/libvirtd can't work). Hence, we
need to use script stanza, source sysconfig, and execute libvirtd
without --daemon. For similar reasons we can't use limit stanza and need
to handle DAEMON_COREFILE_LIMIT in job's script.
