The nova-scheduler during creation of an instance is throwing issue 'Failed to schedule_run_instance: No valid host was found.' This is failing at when it checks that host passes filters or not. Any idea what could be the reason and how to resolve this?
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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.
2012-04-03 12:37:20 WARNING nova.scheduler.manager [req-49ea5605-9e31-4db6-955c-8acd59cf0f82 baaa0b3c108b4626a083007a72d37b01 4eabbf34471d469a91234b769b5b2af3] Setting instance c6ef30e4-ae64-46b8-aab9-700d3e68165a to ERROR state.