Comment 7 for bug 1718212

Hi,

Here is what the virt driver is returning for my cluster. I am using one vSphere cluster (1 compute node) and there are no non-OpenStack instances on this cluster.

2017-09-28 23:04:35.562 3304 DEBUG nova.compute.resource_tracker [req-ae33aa02-bcf8-48dc-8884-9d6ddad56b61 - - - - -] Hypervisor/Node resource view: name=domain-c192.b9564b6d-07ee-4a65-89f2-48244db310b9 free_ram=4549438MB free_disk=74717GB free_vcpus=936 pci_devices=None _report_hypervisor_resource_view /opt/mhos/openstack/nova/lib/python2.7/site-packages/nova/compute/resource_tracker.py:672

If you notice, free_disk is 74717GB.

Next log output:

2017-09-28 22:21:59.466 3304 INFO nova.compute.resource_tracker [req-ae33aa02-bcf8-48dc-8884-9d6ddad56b61 - - - - -] Final resource view: name=domain-c192.b9564b6d-07ee-4a65-89f2-48244db310b9 phys_ram=6241318MB used_ram=2706944MB phys_disk=101720GB used_disk=0GB total_vcpus=936 used_vcpus=1575 pci_stats=[]

Used disk says 0GB and phys_disk says 101720GB.

That's incorrect. The value should be 101720 - 74717.

All of my instances do not have root disks. They are completely ephemeral and our users use volumes to store persistent data. Even then, we should be reporting what the compute node has reported back with.

How this impacts production: There is no check to prevent gross oversubscription of storage.

In theory, I can login, create a 500GB image in Glance, launch 1000 instances on it (which the maths add up to potentially 500000GB, or 500TB) and then run a dd command in all of them simultaneously and destroy my vSphere cluster.