I wrote about one way in which HR and IT can operate more closely, but there's another interaction between IT and HR that might not be so benign.
DevOps is ultimately about breaking down silos in IT (indeed, my definition of DevOps is as a cultural structure where teams work together to meet the needs of the business rather than competing against each other to meet the needs of the team).
However, in a business, individuals and teams are actually playing a game in which the rules and criteria for success are set by HR in the shape of the (often annual) review cycle. And all too often promotions, pay rises, even restructuring, are based around individual and team performance in isolation. And who can blame individuals and teams for optimising their behaviour around the performance targets they've been set?
It's similar to Conway's Law, in which the outputs of an organization mirror its organisational structure - here, the outputs of an organisation will mirror the performance targets that have been set. If you want to improve collaboration and remove silos, then make sure that HR are on board and get them to explicitly put those into the annual performance targets.