Tip of the Day: Dynamic Memory for Linux Guests


Today’s Tip…

In Windows Server 2012 R2, quite a bit of work was put into elevating our support for Linux. One of these areas was in the realm of dynamic memory. For supported Linux distributions, this means that not only can memory be hot added to a virtual machine, but memory can be reallocated to and from the VM as needed by use of a ‘balloon driver’. As more memory is needed from the Linux VM, the balloon driver ‘inflates’ to capture more of the VM’s memory and reallocates it back to the Hyper-V host.

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When more memory is needed by the Linux VM, the balloon is deflated, and memory is returned to the VM.

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Comments (5)

  1. Anonymous says:

    hi,
    any idea when we’ll have a Linux Integration Service for RedHat/CentOS 6.5 and 7?

  2. Anonymous says:

    thanks

  3. Anonymous says:

    Thank you Robert, good tips good picture.

  4. Anonymous says:

    The last I heard, we were trying to negotiate with a number of destros but even if I did know a release date, I wouldn’t be allowed to share it.

    Because the IC (integrated components) is actually shipped with Linux, you might want to check in with whichever you are using.

  5. Gordon Watts says:

    I’ve been using this for a RH machine, and it works very well… except under certain circumstances. Specifically, when I try to compile with gcc a C++ file that depends heavily on boost. The memory profile of the process increases so quickly that I (guess?)
    the balloon can’t deflate fast enough, and the result is I get out-of-memory errors. Re-running the machine with a constant allocation of 3 GB works just fine (when it is dynamic, I think it is just over a GB when the compile starts). So, while the support
    is great for most tasks, be aware there are some circumstances that seem to get this into trouble.