While the optimization is running, you can run the top command, enter M to sort by memory usage, and see how the RES and SHR columns grow for the SOLR Java process. Also hold and look at Mem: free at the top of the screen. As RES and SHR increase, optimization works. In fact, the only thing that would stop this would be if Mem: free drops to zero.
If this happens to you, repeat the optimization with the LARGER number for maxSegments. For example, if 5 segments end with RAM, try 9. Then start again with 8, then again with 7, then try again 5 and 3 and 1.
source share