Embodiments of the present invention address deficiencies of the art in respect to optimization profile generation and provide a method, system and computer program product for user guided generation of network link optimization profiles. Random writes are collected and written to a write cache extension, such as a portion of the SSD storage tier. As a result, the photomultiplier tube can be very easily attached or detached so that even an unskilled person can mount the photomultiplier tube easily and accurately in a predetermined position by screwing. A first fastener is configured for mounting to the graft and the first section to anchor the graft to the first section.