Indeed, SAP wants you to run their products primarily on SUSE Linux Enterprise Server, with RHEL being an "also ran" (despite enjoying full support from SAP).

This despite SLES' controversial and never-working-quite-right "vm.pagecache_limit_mb" kernel parameter (which they're finally ditching in SLES15, I hear).

Don't get me wrong, SLES these days is a mature, high-quality distro (I'm working with hundreds of installations running SAP products), but sometimes they do weird things, like bumping kernel version from 2.6 to 3.0 within one service pack (sometimes back in SLES10 or SLES11 days, iirc).