Step 1: Create a new Mosaic dataset. Step2: Add the raster info function to the Mosaic datasetStep 3: Import the raster information from one of the original rasters(Make sure the spatial reference is defined for the raster that you are using as the template). Step 4: Add the rasters to the Mosaic dataset. Leave the option to build overviews checked off. Step5: Define service overviews. Make sure you set the compression method to LZW (A lossless compression). Step 6: Build service overviews.