The ISMF data class attribute “RLS Above the 2-GB Bar”is one of the three required conditions in determining whether the buffers for a VSAM data set will be above or below the 2-GB bar; the default is below the bar. To make the data class eligible for using the RLS buffers above the bar, specify Yes for “RLS Above the 2-GB Bar” on the Data Class Define or Alter panels. Then assign the VSAM data set to the data class.