Geographically distributed clusters
As truly high-speed wide-area network (WAN) connections become more reliable and more readily available, an emerging trend is the creation of clusters that span sites. As a rule, this is something that should only be implemented after a substantial amount of consideration and planning. In most cases, creating one cluster in each site is far preferable to trying to coerce a multisite cluster to work. Remember that with Hyper-V Server 2012, you can live migrate across clusters using Shared Nothing Live Migration, so you can achieve downtime-free inter-site portability. If downtime-free is not strictly necessary, consider using Hyper-V Replica instead. This is a subject covered in Chapter 12, Backup and Disaster Recovery.
Things to consider for a geographically distributed cluster are as follows:
Inter-site network latency and reliability are absolutely critical. Average latency should be at or below 100 milliseconds; 60 or below is preferable.
Inter-site connection...
