On Wed, Apr 19, 2017 at 01:29:01PM -0600, Jim Fehlig wrote: > libvirtd can spawn threads/tasks when creating new domains for > some hypervisors such as Xen's libxl driver, quickly reaching > the cgroups pids controller default TasksMax setting of 512. When > the limit is reached, attempting to create additional domains > results in an error from the cgroups pids controller, e.g. > > kernel: [71282.213347] cgroup: fork rejected by pids controller in > /system.slice/libvirtd.service > > Depending on domain type and configuration, anywhere from 4-7 > threads/tasks may be created by libxl when starting a domain. > In order to support 4096 domains, similar to commit 27cd763500, > increase the TasksMax setting in libvirtd.service to > 4096 * 8 = 32768 tasks. > > Signed-off-by: Jim Fehlig <jfehlig@xxxxxxxx> > --- > daemon/libvirtd.service.in | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/daemon/libvirtd.service.in b/daemon/libvirtd.service.in > index 899abdf37..fbaf02f3b 100644 > --- a/daemon/libvirtd.service.in > +++ b/daemon/libvirtd.service.in > @@ -29,6 +29,11 @@ Restart=on-failure > # If changing this, also consider virtlogd.service & virtlockd.service > # limits which are also related to number of guests > LimitNOFILE=8192 > +# The cgroups pids controller can limit the number of tasks started by > +# the daemon, which can limit the number of domains for some hypervisors. > +# A conservative default of 8 tasks per guest results in a TasksMax of > +# 32k to support 4096 guests. > +TasksMax=32768 > > [Install] > WantedBy=multi-user.target ACK 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 :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
