Description of problem:

For VM removal in data center with hosts which are non operational,
failure messages are not informative enough:

1) User get error event: "Failed to remove VM <name>"
Can it be more informative? Why does it fail(no up/spm host on data center), or what should be done to allow it's removal (turn hosts to up). 

2) On engine log (attached), error is not so clear or informative on what the root cause is:

2012-06-27 15:37:21,946 ERROR [org.ovirt.engine.core.bll.RemoveVmCommand] (pool-3-thread-48) [6ad336a] Command org.ovirt.engi
ne.core.bll.RemoveVmCommand throw Vdc Bll exception. With error message VdcBLLException: Cannot allocate IRS server
2012-06-27 15:37:21,951 INFO  [org.ovirt.engine.core.bll.RemoveVmCommand] (pool-3-thread-48) [6ad336a] Command [id=ccc6005d-5
022-48bc-be90-9e910ef29c1c]: Compensating CHANGED_STATUS_ONLY of org.ovirt.engine.core.common.businessentities.VmDynamic; sna
pshot: EntityStatusSnapshot [id=64f0a3ea-2bfa-435a-bd0b-d9e3b39786fb, status=Down].

Version-Release number of selected component (if applicable):

SI7

How reproducible:

always

Steps to Reproduce:
1. Add host with wrong cpu type, in order to have it non-operational 
2. add (iscsi) storage domain
3. add vm (with no disk)
4. try to remove the VM
  
Expected results:

Give user information of actions he should take to be able to remove the VM,
or explain why VM can't be removed.