Neither program supports concatenation of unlike input (for example, data sets on DASD and tape). Data sets on different devices similar in type are acceptable (for example, 3350 and 3380). If the input data sets to be concatenated are similar in device type but have differing blocksizes, then the normal concatenation rules still apply (the largest blocksize must be first in the concatenation). Note that the programs will not process SMF data directly from the SMF system data sets. The circumvention for all of these restrictions is the same: copy the appropriate portion of the SMF data so that all inputs are in similar format. IFASMFDP can be used to do this, unless reblocking is required (IFASMFDP always forces its output to the same LRECL and BLKSIZE). To reblock, use IDCAMS or IEBGENER and specify DCB information for the output data set.