David Holmes wrote: > Hi Jan, > > You can use the environment variable _JAVA_OPTIONS to set -Xmx. > > The other option is to use your own wrapper script for launching the > VM that contains whatever flags you need. > > we would really like to avoid a wrapper script. The env var _JAVA_OPTIONS is a nice workaround, although I'm not thrilled about the fact that I now see
$ java -version Picked up _JAVA_OPTIONS: -Xmx256M java version "1.6.0_20" OpenJDK Runtime Environment (IcedTea6 1.9.10) (rhel-1.23.1.9.10.el5_7-x86_64) OpenJDK 64-Bit Server VM (build 19.0-b09, mixed mode) Is there any way to get rid of that message? thx, JJK / Jan Just Keijser > On 17/11/2011 11:28 PM, Jan Just Keijser wrote: >> hi all, >> >> I would like to report an issue with OpenJDK 1.6 (and Oracle Java 6u29) >> that we have run into on our grid computing farm: >> >> the latest&greatest worker nodes have 12 cores and 48 GB of RAM ; we >> offer a maximum 12 jobs slots on these worker nodes, in order to >> accomodate small and large jobs (users can requests 1 - 12 cores). To >> ensure that the different jobs don't interfere with each other we also >> set a VMEM limit for each job slot. The current VMEM limit is 48 / 12 = >> 4 GB RAM per job slot. Each single core job that starts has a 'ulimit >> -v' of 4,000,000 . >> >> On these boxes OpenJDK 'java' refuses to start: >> >> $ java -version >> Error occurred during initialization of VM >> Could not reserve enough space for object heap >> Could not create the Java virtual machine. >> >> After some debugging I found that this is caused by the default maximum >> heap size which java allocates: it scans /proc/meminfo to extrac the >> amount of RAM installed and divides it by 4 ; an 'strace' shows that >> indeed 'java' tries to do an 'mmap' call for 12 GB of RAM ! >> >> A work around is to always specify '-Xmx2GB' or something similar but >> this does not work for all software that we use , plus , I find it >> annoying that I have to tell this to all my users. >> >> What I would like to see is a system-wide setting for the initial >> maximum heap size, so that >> java -version >> "just works" . Is this possible? >> >> thanks in advance, >> >> JJK / Jan Just Keijser >> >>
