I see this error in attached engine.log file. 2014-08-25 09:00:26,031 INFO [org.ovirt.engine.core.bll.scheduling.SchedulingManager] (org.ovirt.thread.pool-6-thread-16) [29765492] Candidate host KVM02 (12dfa3ea-13cf-4918-b31 6-0c5643bd96be) was filtered out by VAR__FILTERTYPE__INTERNAL filter Memory (correlation id: 29765492) [-] 2014-08-25 09:00:26,032 ERROR [org.ovirt.engine.core.bll.MigrateVmToServerCommand] (org.ovirt.thread.pool-6-thread-16) [29765492] Command org.ovirt.engine.core.bll.MigrateVmToSer verCommand throw Vdc Bll exception. With error message VdcBLLException: RESOURCE_MANAGER_VDS_NOT_FOUND (Failed with error RESOURCE_MANAGER_VDS_NOT_FOUND and code 5004) Seems like kvm02 doesn't have enough memory to accommodate load of new virtual machine. Check "Max free Memory for scheduling new VMs:" available for the host. (Admin portal > Hosts > select intended host > General) and verify that its grater than "Physical Memory guaranteed" value set for the subjected virtual machine (In Resources Allocation tab inside Edit Virtual Machine window). If it's higher, Reduce it and then try migrating. Regards, Prasad Mukhedkar -------- Original Message -------- Subject: RE: [ovirt-users] Migration failed, No available host found Date: Tue, 26 Aug 2014 09:13:45 +0800 From: PaulCheung <eq2008(a)msn.com&gt; To: Omer Frenkel <ofrenkel(a)redhat.com&gt;, &quot;prasad(a)mukhedkar.com&quot; <prasad(a)mukhedkar.com&gt; Dear Both, Attachment is the engine.log. All 3 server are in the same cluster: Default The machine is a 2way 8 core 96G RAM, each VM has 2G, and I saw the CPU/RAM status, sure have enough resource, the clour is green. I want to solve it as soon as possible, so I update it from 3.4 to 3.4.3 all 3 servers last night, but still not work. But now, I came back this morning, migration was success, I don't know why. Here is the error ID: ID 166 2014-8-25, 18:52 Migration failed, No available host found (VM: ALD-AL1-006, Source: KVM01). kvm02.