Increase readahead to 2048

Change-Id: I95bc439e709181acfd3fb59035e207c3b2eb9cee
Change LOCALVERSION to Vanir

Change-Id: I44fd453a3934d686f4f25ed7bf93bcdf4186548f
Merge "Increase readahead to 2048" into sonic-dev
Merge "Change LOCALVERSION to Vanir" into sonic-dev