If you try to install Oracle 10g on Oracle Enterprise Linux5, by using runInstaller the following error will appear:
Checking operating system version: must be redhat-3, SuSE-9, redhat-4, UnitedLinux-1.0, asianux-1 or asianux-2
Failed <<<<
You need to start runInstaller with ignoresysprereqs parameter as mentioned in metalink notes given below
./runInstaller -ignoreSysPrereqs
Before starting install of 10gr2 on Oracle Enterprise Linux5, be sure to go through these metalink notes:
For Linux x86 : Metalink Note 419646.1
For Linux x86_64: Metalink Note 421308.1
These two notes have details of all the os prerequisites for installation of 10gr2