Occasional Lustre releases will be designated as LTS (Long Term Stability) releases and have a series of maintenance releases that will include only small fixes and not major new functionality. 2.10.6 is the current LTS release. However, 2.12.x is the next LTS stream. A final 2.10.7 is planned around the time that 2.12.1. See: http://lustre.org/roadmap/.