ESXi

 View Only
  • 1.  Memory Compression Cache

    Broadcom Employee
    Posted Aug 16, 2012 06:36 AM

    Whatever the memory compression cache is for per vm that is deducted from the memory allocated to the vm or this is other than the memory allocated to per vm?



  • 2.  RE: Memory Compression Cache

    Posted Aug 16, 2012 11:22 AM

    ESXi uses host memory for the compression cache.

    see http://www.vmware.com/files/pdf/mem_mgmt_perf_vsphere5.pdf (page 11) for details.

    André



  • 3.  RE: Memory Compression Cache

    Posted Aug 16, 2012 11:51 AM

    Hi Ranjana that is deducted from the memory allocated to the vm.



  • 4.  RE: Memory Compression Cache

    Broadcom Employee
    Posted Aug 16, 2012 03:22 PM

    That means what u r saying according to that if 2gb RAM is allocated to an vm then 10% that is 200mb is deducted and only near about 1800mb RAM will be available to the VM.

    Now my doubt is:

    is it reserved? or deducted only when memory compression is required?



  • 5.  RE: Memory Compression Cache

    Posted Aug 16, 2012 04:33 PM

    It's not deducted only exist when memory compression is required.



  • 6.  RE: Memory Compression Cache

    Broadcom Employee
    Posted Aug 16, 2012 04:39 PM

    Then how much RAM will be available to the VM normally.



  • 7.  RE: Memory Compression Cache

    Posted Aug 16, 2012 04:52 PM

    Did you see the document I attached in my previous post?

    André



  • 8.  RE: Memory Compression Cache

    Posted Aug 16, 2012 05:05 PM

    Compression is done only of the pages which will be otherwise be swaped, The VM at any time if required can use complete allocated memory.



  • 9.  RE: Memory Compression Cache

    Posted Aug 16, 2012 05:21 PM

    Ranjna Aggarwal wrote:

    Then how much RAM will be available to the VM normally.

    Only pages that would otherwise be swapped out to disk are chosen as candidates for memory compression.