If you are getting the error message as “Error on zimbra server Could not create the Java virtual machine” in /opt/zimbra/log/zmmailboxd.out log file you can fixed this issue by lowering the heap size as below:
#su zimbra
#zmlocalconfig -e mailboxd_java_heap_memory_percent=10
#zmlocalconfig -e mailboxd_java_heap_memory_percent=10
restarted zimbra server
#zmconrol restart
Now issue should be fixed.