I have a 2-node Windows 2008 R2 Enterprise SP1 64bit cluster with 9 SQL 2008 R2 SE 64bit FCI's on it. When installing new SQL2012 FCI's it takes 25 minutes or longer to step through each GUI screen.
When checking the installation logs I can see setup verifying and re-verifying all kinds of things (disks, names...) related to the instances already present.
Never experienced this with 2008R2. I know SQL 2008R2 clustered install has a "delay" issue when using mount points (HF available) but this time it's all over the GUI.
Even when starting setup it takes around 20 minutes before the landing page is displayed. This is a piece of the log (when I started setup, nothing more) where it seems to hang for 23 minutes.
(01) 2014-03-24 14:13:19 Slp: Running Action: FinalCalculateSettings
(01) 2014-03-24 14:37:47 Slp: Completed Action: FinalCalculateSettings, returned True