You have a System Center 2012 Configuration Manager environment. Your company identifies virtual machines by adding an additional attribute named is Virtual and setting it to TRUE for the computer…

Creating a collection alone does not populate it with the correct data; the discovery method must first be configured to retrieve the isVirtual attribute before it can be used as a membership criterion.

Initiating a discovery data collection cycle on clients resends existing hardware and software inventory data already gathered - it does not extend AD System Discovery to read new custom LDAP attributes.

Active Directory System Group Discovery identifies computers by their group membership in AD, not by custom object attributes like isVirtual on computer objects.

Active Directory System Discovery supports adding custom LDAP attributes - such as isVirtual - to its discovery scope. Once configured, SCCM reads the isVirtual attribute value from each computer object in AD and stores it in the discovery data record (DDR). This attribute can then be used as a query rule to dynamically populate a collection for virtual machines.