Q: Are there any volume size limits imposed by Failover Clustering?
A: Failover Clustering typically leverages NTFS (although Windows Server 2012 R2 adds ReFS support). Failover Clustering imposes no limitaions related to the maximum size of a volume it leverages. This means the existing NTFS limits would apply to volumes used by Failover Clusters. A good resource for NTFS and volume limits is at the Microsoft page "Reviewing Storage Limits."