On Wed, Apr 18, 2018 at 06:27:10PM +0800, llilulu wrote: It isn't a QEMU bug - it is the kernel telling you that you have hit the max process limit. 80 guests is honestly not a very large value though, so I'm surprised it would hit a max process limit. Unless perhaps you're using RBD storage as that creates an insanely huge number (100+) of threads sometimes. Check /proc/$PID/limits for one of the guests that it successfully running and it will tell you current "Max processes" limit. Then in /etc/libvirt/qemu.conf try setting max_processes to a larger value and restart libvirtd. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|