It looks like Oregon State was the only one of the nine Pac-12 teams to qualify that didn't advance, as they lost in 5 sets to NC State.
http://pac-12.com/article/2017/12/01/ncaa-womens-volleyball-tournament-eight-pac-12-teams-advance
http://pac-12.com/article/2017/12/01/ncaa-womens-volleyball-tournament-eight-pac-12-teams-advance