With Samba using a clustered database, you can now export the same shared storage (this is only on the gfs2 file system - I haven’t seen any testing on ocfs2) on multiple nodes in an active/active samba cluster. The storage on clients that mount this export will be available when active failover occurs from one server node to another.

Opportunistic locking is part of the Windows client file caching mechanism. Samba implements opportunistic locking as a server-side component of the client caching mechanism. Samba/CIFS doesn’t play nice with NFS, so if you’re in a mixed environment where some windows machines access and modify the same files that Linux or Solaris touch through NFS, then disable the oplocks. This is important for things like database files to avoid corruption!