HP StorageWorks Storage Mirroring Recover User's Guide (T5437-96021, November 2010)

Workload protection Page 339 of 677
NetBIOS
Because NetBIOS is not available on Windows 2008, if you are using Windows 2008 in
a workgroup environment and do not have DNS host records, there may be a delay of up
to five minutes before the failed over source server name is available for client access.
See About the NetBIOS Interface in the MSDN library.