Alternative for RDM in Cluster

Dear All,

I have a SQL Server 2008R2 SP1 cluster on Windows 2000R2 ,Now we have an issues with RDM,
Hence we want go with any other alternative solutions for Storage.

Please some one suggest us which is Best solution for Storage to come out RDM for VM's or Physical machines to configure Cluster.

We are ready for Upgrading OS and SQL Servers to Higher version like  SQLServer 2012.

Please suggest us best solution to get ride of RDM and AlwayON  for High availability.



Regards, 

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SNIVAS