Open Stack

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 at 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?