when you want to install SFB CMs database skeleton on SQL failover cluster add the parameter UseDefaultSQLpaths . If not the cmdlet may wrigly guess the default location and will fail.
Install-CsDatabase -CentralManagementDatabase -SQLServerFQDN chglsqlvssfb15.IUCN.sys -SQLInstanceName SFB2015 -UseDefaultSQLpaths -Verbose
