In my experience, perhaps 85% of SAP performance problems are considered to be storage-related. This is not to say that 85% of all SAP problems can be traced back to the storage system—but by the time I am called in, the easy fixes are typically taken care of. So I rarely run into simple profile parameter problems, or issues with other hardware subsystems, or problems with the network, either. Instead, after a quick review of the entire solution stack I usually find myself drilling down into the following:
The model and features of the disk subsystem servicing the systems that exhibit the slow performance
Details as to how the disk subsystem has been configured
Database statistics, to quantify how well the database ...