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  • 1.  Why Thick disk with eagerzeroed for FT?

    Broadcom Employee
    Posted Jul 30, 2012 06:19 AM

    Why Thick disk with eagerzeroed for FT? what is the logic behind that?



  • 2.  RE: Why Thick disk with eagerzeroed for FT?

    Posted Jul 30, 2012 07:03 AM

    I think the answer to your question is that an eager zeroed thick disk gives the best performance. From the Performance Best Practices for VMware vSphere™ 5.0:

    An eager-zeroed thick disk has all space allocated and zeroed out at the time of

    creation. This increases the time it takes to create the disk, but results in the best performance,

    even on the first write to each block.



  • 3.  RE: Why Thick disk with eagerzeroed for FT?

    Broadcom Employee
    Posted Jul 30, 2012 07:29 AM

    That i Know it gives good performance but is that only due to performance?



  • 4.  RE: Why Thick disk with eagerzeroed for FT?

    Posted Jul 30, 2012 07:43 AM

    For FT to work it needs to enable multi-writer mode on disks which are shared by the primary and secondary VM. Multi- writer mode can only be enabled on eagerzeroed disks...  More info here: http://kb.vmware.com/kb/1034165

    /Rubeck



  • 5.  RE: Why Thick disk with eagerzeroed for FT?

    Broadcom Employee
    Posted Jul 31, 2012 05:25 PM

    But i tested FT in my test environment without using this multi-writer flag. it was working well even without using any such option.



  • 6.  RE: Why Thick disk with eagerzeroed for FT?

    Posted Jul 31, 2012 05:53 PM

    FT enabled multi-writer for you.