Could not reserve enough space for 2097152KB object heap

To rewsolve the above issue just go to the config file of the elastic search and change the JVM options to the memory value that suits your hardware. 

Go to : jvm.options

Change the below params:

-Xms200m --- for the 200 MB

-Xmx500m -------for 500 MB 

you change the values as per your PC configurations, the "m" suggest MB and and "g " as in GM.