Dynamic Memory and Clustering - will memory be withdrawn from running VM's to allow for VM's (from failed host server) to start?

i trying figure out happen if have 2 servers in hyper-v cluster, both of running windows 2008 r2 sp1 , using dynamic memory.  what happens if 1 host fails?  will hyper-v on running host reduce amount of memory it's running vm's allow new vm's (migrated failed host) start?

here example:

host1 (32gb ram): app1 (startup ram: 4gb, max: 15gb, current 15gb), app2 (startup ram: 4gb, max: 15gb, current 15gb)

host2 (32gb ram): app3 (startup ram: 4gb, max: 15gb, current 15gb), app4 (startup ram: 4gb, max: 15gb, current 15gb)

now, if host2 fails, host1 try start app3 , app4.  but won't have enough memory because app1 , app2 using 30gb of 32gb physical ram.  will reduce amount of ram used app1 , app2 can start app3 , app4?  or necessary (or idea) reduce max memory on vm's there enough free physical memory in host startup vm's failed host?

i hope makes sense someone.  the possibility of using dynamic memory on 2 node cluster eliminate need have double amount of ram in each server otherwise need.

thanks!   dbaddorf

yes. remember when there unplanned failover, vms restarted on available node - meaning ram required, os value configured on startup ram. when youre dealing planned failovet, live migration, need calculate current memory usage.

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kristian (virtualization , coffee: http://kristiannese.blogspot.com )

Windows Server  >  Hyper-V