RMS_DFMBFSDK is a system parameter that establishes the default RMS multibuffer count for sequential disk operations. This value defines the number of I/O buffers that RMS allocates for sequential disk files. The default value is usually adequate. However, if read-ahead or write-behind operations are used, a larger number improves performance. You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_ DEFAULT. RMS_DFMBFSDK is an AUTOGEN and DYNAMIC parameter.