Apache HBase "Could not reserve enough space for heap offset array"

1. Run "./bin/hbase shell",
   

   $ ./bin/hbase shell
   Error: Could not create the Java Virtual Machine.
   Error: A fatal exception has occurred. Program will exit.
   Error occurred during initialization of VM
   Could not reserve enough space for heap offset array
   

2. "Could not reserve enough space for heap"?
3. Edit "./conf/hbase-env.sh",
   

   $ vi conf/hbase-env.sh
   export _JAVA_OPTIONS='-Xmx256m -Xms64m'
   
   # Extra Java CLASSPATH elements.  Optional.
   # export HBASE_CLASSPATH=
   
   # The maximum amount of heap to use, in MB. Default is 1000.
   export HBASE_HEAPSIZE=128