Stop all SQL Server services (Cluster Manager – Take Offline Services SQL only).
Assigning the new storage volumes and Drive Letter’s temporary copies.
Full copy of all existing data, keeping the ACLs of existing volumes to new ones.
Removal of dependencies on the SQL Service of old records.
Removing the Drive Letter’s of old records and assignment of these new discs to Drive Letters (attention has to be guaranteed that all drive Letters are kept for each volume replaced)
We recommend that prevented access by the operating system on both nodes to the old disk (disable the making of the Path, or another method which ensures that the OS does not access the old disk), but keeping the data intact in case you need to RollBack.
Allocation of new volumes in the SQL Cluster Group.
Making even the services of SQL “Offline” Move SQL group for each of the physical nodes in the cluster, must raise all funds, with the exception of SQL Services. With this step we ensure that the new volumes are correctly recognized by the OS of each physical node.
Assign dependencies removed in section 5 to the SQL Service, should be exactly the same as previously existing.
Making again the SQL Failover Group, even with the SQL services “Offline”, among all physical nodes in the cluster.
Making the Bring Online Services and SQL Move Group from all physical nodes in the cluster to ensure that the SQL service is started successfully on all physical nodes in the cluster.
You can follow the following article concerning optimization of the discs to SQL Server 2008: