On Wed, Apr 18, 2018 at 06:27:10PM +0800, llilulu wrote:

Hi: My libvirt is 3.4.0 and qemu is 2.9.0, My host has a big memory(128G), I run many guest on my host(80 guests), when I batch stop and start guests, some guest will crash, the qemu log is "qemu: qemu_thread_create: Resource temporarily unavailable". I search qemu code, I find qemu_thread_create just like pthread_create function. I search on internet, someone say that is a bug of qemu.Because my host run many guest ,so I cann't ensure whether qemu bug or my host load heavy cause my guest crash. Can someone tell me what reason cause the promble? and what can I do avoid the promble?

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 :|