Migrated an apps to Windows Azure - previous platform was windows server 2008 R2. When I try to configure os it gives me two options with Windows Server 2008 SP2 being default. Are there any known issues of selecting Windows Server 2008 R2? Any performance implications. I was assuming that since R2 was released later and had some enhancements related to virtualization etc it should be better.
Yes, I'd go for Windows Server 2008 R2, which is based on the Windows 7 kernel rather than the Vista kernel used by Windows Server 2008 SP2.
I'd expect that Microsoft make the 2008 SP2 option available for Azure customers that have not yet tested their applications under the newer platform.