I successfully blacklisted the "memory balloon" driver in a VM image and found that another driver is choking on the large memory. The guys in #centos think it might be the USB or PS/2 drivers. Since these are kernel drivers they cannot be blacklisted; the only way to not load them is to not call them. On the hypervisor in /etc/libvirt/qemu/<instance-name>.xml I see this: <input type='tablet' bus='usb'> <address type='usb' bus='0' port='1'/> </input> <input type='mouse' bus='ps2'/> <input type='keyboard' bus='ps2'/> I tried removing those lines, but it looks like the XML file is re-created whenever I stop and start the VM. In nova.conf I see "#pointer_model = usbtablet" If I set "pointer_model = <None>" on the HV and then restart nova, I see this in the log: 2020-03-03 11:05:17.233 228915 ERROR nova ConfigFileValueError: Value for option pointer_model is not valid: Valid values are [None, ps2mouse, usbtablet], but found '<None>' If I set "pointer_model = None" then I see this: 2020-03-03 11:06:24.761 229290 ERROR nova ConfigFileValueError: Value for option pointer_model is not valid: Valid values are [None, ps2mouse, usbtablet], but found 'None' What am I missing? # # Generic property to specify the pointer type. # # Input devices allow interaction with a graphical framebuffer. For # example to provide a graphic tablet for absolute cursor movement. # # If set, the 'hw_pointer_model' image property takes precedence over # this configuration option. # # Possible values: # # * None: Uses default behavior provided by drivers (mouse on PS2 for # libvirt x86) # * ps2mouse: Uses relative movement. Mouse connected by PS2 # * usbtablet: Uses absolute movement. Tablet connect by USB # # Related options: # # * usbtablet must be configured with VNC enabled or SPICE enabled and SPICE # agent disabled. When used with libvirt the instance mode should be # configured as HVM. # (string value) # Possible values: # <None> - <No description provided> # ps2mouse - <No description provided> # usbtablet - <No description provided> pointer_model = None -----Original Message----- From: Albert Braden Sent: Wednesday, February 5, 2020 9:34 AM To: openstack-discuss@lists.openstack.org Subject: RE: Virtio memory balloon driver When I start and stop the giant VM I don't see any evidence of OOM errors. I suspect that the #centos guys may be correct when they say that the "Virtio memory balloon" device is not capable of addressing that much memory, and that I must disable it if I want to create VMs with 1.4T RAM. Setting "mem_stats_period_seconds = 0" doesn't seem to disable it. How are others working around this? Is anyone else creating Centos 6 VMs with 1.4T or more RAM?