H2o not fully accessing memory on a cluster

Question

So this may be odd, but H2O doesn't seem to be accessing the memory available to it in my cluster. It is supposed to be using 24 cores and 512GB total RAM but only sees 26.67 Gb of RAM (but all 24 cores). I am running H2o in R.

h2o.init(nthreads=-1,max_mem_size = "500g")

H2O is not running yet, starting it now...

Note:  In case of errors look at the following log files:
/tmp/Rtmpx9ndSU/h2o_ra2816_started_from_r.out
/tmp/Rtmpx9ndSU/h2o_ra2816_started_from_r.err

openjdk version "1.8.0_121"
OpenJDK Runtime Environment (build 1.8.0_121-b13)
OpenJDK 64-Bit Server VM (build 25.121-b13, mixed mode)

Starting H2O JVM and connecting: . Connection successful!

R is connected to the H2O cluster: 
H2O cluster uptime:         1 seconds 304 milliseconds 
H2O cluster version:        3.10.5.2 
H2O cluster version age:    4 days  
H2O cluster name:           H2O_started_from_R_ra2816_qpf255 
H2O cluster total nodes:    1 
H2O cluster total memory:   26.67 GB 
H2O cluster total cores:    24 
H2O cluster allowed cores:  24 
H2O cluster healthy:        TRUE 
H2O Connection ip:          localhost 
H2O Connection port:        54321 
H2O Connection proxy:       NA 
H2O Internal Security:      FALSE 
R Version:                  R version 3.3.2 (2016-10-31) 

I would appreciate any help or ideas about the issue.

Answer 1

I have solved the issue. By putting the following before initializing H2O:

options(java.parameters = "-Xmx500000m")