Hadoop – java.io.IOException: error=12, Cannot allocate memory

 Triviality
Feb 072012
 

I hit this problem in my project which is hadoop-based:

Cannot run program "chmod": java.io.IOException: error=12, Cannot allocate memory

Did some research but found nothing useful – everybody mentioned it’s JDK’s problem not using fork()+exec() which caused excessive memory allocated during spawning new process for running shell command. However, it’s weird that I hit this problem on my AWS micro instance only, not on my MacBook, so I moved on to check some more –

It turned out swap is a problem, my micro instance in AWS does not have swap enabled (i.e. zero swap space), after add 1G swap everything’s fine now.

I’m a Java newbie, so my question is, though it got solved, did I do something properly?

  One Response to “Hadoop – java.io.IOException: error=12, Cannot allocate memory”

  1. Hang says:
    2012-02-07 at 16:21

    BTW, write down how to turn on a file based swap space so not to spend time on searching …


    # all with root
    dd if=/dev/zero of=/root/swapfile bs=1M count=1024
    chmod 600 /root/swapfile
    mkswap /root/swapfile
    swapon /root/swapfile
    swapon -s # to make sure it IS on
    echo "/root/myswapfile swap swap defaults 0 0" >> /etc/fstab # to make it enabled after reboot

Sorry, the comment form is closed at this time.