Hi all, hopefully a useful bit of info.
We recently struggled to install Tableau Server 10.1 on to a XenServer virtual Windows server. Neither an upgrade from 9.3.6 nor a fresh install would work.
What appeared to be a Postgres permissions issue turned out to be a compatibility problem between Tableau 10 and XenServer version 6.5.
The solution was to upgrade XenServer to 6.5 Service Pack 1, though XenServer 7 I believe would also be fine.
Got there with the help of Tableau Tech Support... but be warned!