VMAX: Which Allocation Formats for Virtual Machines does VMWare VMFS offer and how do those format affect VMAX allocation and Reclaim for Virtually Provisioned Devices?

           

   Article Number:     502930                                   Article Version: 4     Article Type:    How To 
   

 


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VMAX Family,Unisphere for VMAX,Solutions Enabler

 

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Which Allocation Formats for Virtual Machines does VMware VMFS offer and how do those formats affect VMAX allocation and Reclaim for Virtually Provisioned Devices?.   
   
    When monitoring capacity allocations from both VMFS and VMAX Thin Pool/SRP allocations perspective, it is possible to see:   

      VMFS Allocations greater than VMAX Thin Device allocations     
      VMFS Allocations less than VMAX Thin Device allocations   
   
    The reasons for this will depend on which allocation format was selected when creating the Virtual Machine. Allocation format "zeroedthick" is the default allocation type, and the other formats are "thin" and "eagerzeroedthick".   
   
    For full details on these Allocation formats in relation to VMAX allocations, see section "Virtual Disk Allocation Schemes" from Techbook "Using EMC VMAX Storage in VMware vSphere Environments", available from:    
    http://www.emc.com/collateral/hardware/solution-overview/h2529-vmware-esx-svr-w-symmetrix-wp-ldv.pdf