Simulator Discussions

DATA ONTAP 8.3 Cluster on Esx Getting Error Disk not found after power on the vm .


DATA ONTAP 8.3 Cluster on Esx Getting Error Disk not found after power on the vm .


Error :


[ Failed to start the virtual machine.
Module DiskEarly power on failed.
Cannot open the disk '/vmfs/volumes/d1c0391d-a50882a4/RHEL_Test/vsim_esx-cm/DataONTAP-sim.vmdk' or one of the snapshot disks it depends on.
The system cannot find the file specified
VMware ESX cannot find the virtual disk "/vmfs/volumes/d1c0391d-a50882a4/RHEL_Test/vsim_esx-cm/DataONTAP-sim.vmdk". Verify the path is valid and try again. ]





To fix the problem permanantely, do this.  Use vmkfstools to basically clone off the VDMK into a format that doesn't require the multiextent module loaded.



To load the vmkernel multiextent module:
  1. Open a console to the ESXi host. For more information, see Using Tech Support Mode in ESXi 4.1 and ESXi 5.x (1017910).
  2. Run this command to load the multiextent module:

    # vmkload_mod multiextent
  3. Check if any of your virtual machine disks are of a hosted type. Hosted disks end with the -s00x.vmdk extension.
  4. Convert virtual disks in hosted format to one of the VMFS formats.

    To convert virtual disks in hosted format to one of the VMFS formats:
    1. Clone source hosted disk to a new disk using one of these commands:

      For a thick vmdk disk:
      • # vmkfstools -i VM-name.vmdk <VM-name-new-disk>.vmdk -d zeroedthick
      • # vmkfstools -i VM-name.vmdk /vmfs/volumes/destination_datastore/vmfolder/<VM-name-new-disk>.vmdk -d zeroedthick
      For a thin vmdkdisk:
      • # vmkfstools -i VM-name.vmdk <VM-name-new-disk>.vmdk -d thin
      • # vmkfstools -i VM-name.vmdk /vmfs/volumes/destination_datastore/vmfolder/<VM-name-new-disk>.vmdk -d thin

    2. Delete the hosted disk after successful cloning using the command:

      # vmkfstools -U VM-name.vmdk
    3. Rename the cloned VMFS type new disk to the original disk name using the command:

      vmkfstools -E VM-name-new-disk.vmdk VM-name.vmdk

  5. Run this command to unload the multiextent module:

    # vmkload_mod -u multiextent


To be specfic, use vmkfstools to clone DataONTAP-sim.vmdk


If you do a lot of work with simulators, its easier to just persistently enable multiextent:


add the following:

localcli system module load -m multiextent


to this file:



right before this line:

exit 0


Credit to William Lam:




I had the same problem today and eventually resolved it by following the recommended solution in this thread.

To quote 

The Fix: all you have to do is ssh into your host and run this command from the cli:  

# vmkload_mod multiextent

Unfortunately after a ESXi host reboot the multiextent module unloads and you have to perform this again to get your Sims to boot. If anyone can find a way to make this persistent with a switch or write a script that makes it load upon host reboot. I'm sure everyone would be very thankful.


I'm running 8.3 RC1 on ESXi 5.5 U2. As soon as I'd done the vmkload_mod multiextent I was back in business.





Yup Excellent i was able to resolve it . thanks   . I didnot try permanent solution but its non prod dev esxi and no plan for reboot now but will try the perm solution later some time. 


Hi, Guys


Another Way to have some Sim running with ESX 5,5 ....


Put the sim files on a disk accesible by the vcenter, and with the Vmware Converter do a convertion to the vSphere cluster with the files in sources  ...

And dollow the documentations of SIM installation




And another way:

Delete the 250gb disk on IDE1:1, and replace it with a new one.  Thin provisioned is ok.


As long as its done before the first boot, the sim will partition it during init and mount it on /sim



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