Hi,
Go through the following articles, it might help.
Installing a Symantec Endpoint Protection (SEP) client to a cluster server
http://www.symantec.com/docs/TECH91154
How to exclude 2008 R2 Cluster Shared Volumes from Symantec Endpoint Protection
http://www.symantec.com/docs/TECH140062
What scan exclusions should be applied to all Windows clustered server nodes
http://www.symantec.com/docs/TECH105581
Symantec Endpoint Protection 12.1 - Virtualization Best Practices
http://www.symantec.com/business/support/index?page=content&id=TECH173650