When KVM Host does not have enough ram, "nova show " does not show a fault message

Steps to reproduce:
1. use a kvm host that is running as a vm on an esx host with 2048 Megs of RAM
2. on the controller do "nova boot --flavor 1 --image <valid-image-id> vm1
3. do the same nova boot command to create a vm2, vm3, vm4,.....
4. at some point, the nova boot command will fail because there won't be enough memory. You will see a message about ram filter in the nova-scheduler:

2012-04-03 12:37:20 DEBUG nova.scheduler.host_manager [req-49ea5605-9e31-4db6-955c-8acd59cf0f82 baaa0b3c108b4626a083007a72d37b01 4eabbf34471d469a91234b769b5b2af3] Host filter function <bound method RamFilter.host_passes of <nova.scheduler.filters.ram_filter.RamFilter object at 0x4217150>> failed for mymachine-host from (pid=4567) passes_filters /home/myuser/openstack/nova/app/nova/scheduler/host_manager.py:160

2012-04-03 12:37:20 WARNING nova.scheduler.manager [req-49ea5605-9e31-4db6-955c-8acd59cf0f82 baaa0b3c108b4626a083007a72d37b01 4eabbf34471d469a91234b769b5b2af3] Failed to schedule_run_instance: No valid host was found.

5. do a "nova show <vm name that failed>" and notice that there is no "fault" line in the output.

The fault line should show why a vm was not created. The nova show command will show a fault line if the fault_instances table has data in it. So the last "nova boot" command failed to create the vm. When that happened the OpenStack code should have added an entry to the fault_instances table with information about why the vm was not created.

To see a fault created correctly, do this:
1. set auto_assign_floating_ip to true in /etc/nova/nova/conf on either the controller or the kvm host (I am not sure which one it the right one)
2. make sure you do NOT have any floating ip pool configured
3. do "nova boot --flavor 1 --image <valid-image-id> <vm-name>"
4. do "nova show <vm-name>"
notice that there is a "fault" line in the output that will include a message about why the vm was not created.

The same thing should happen in all cases where a vm is not created.