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Adding an RDM to a virtual machine fails with the error: File [datastorename] foldername/filename.vmdk is larger than the maximum size supported by datastore (1029697)

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  • Unable to add an RDM to a virtual machine
  • Adding an RDM to a virtual machine fails
  • The ADD RDM wizard fails
  • You see the error:

    File [datastorename] foldername/filename.vmdk is larger than the maximum size supported by datastore

  • In the vmkernel (ESX) or in messages (ESXi) log, you see messages similar to:

    Nov 24 17:24:52 vmkernel: 1:05:16:01.463 cpu16:4508)WARNING: NMP: nmpDeviceAttemptFailover: Retry world failover device "naa.6006016011802600ae12973ac6f7df11" - failed to issue command due to Not found (APD), try again...


  • This situation can occur when a LUN becomes inaccessible due to space constraints on the volume, or the RDM device is full.
  • This situation can occur when an active datastore LUN or existing RDM LUN is in an All Paths Down (APD) condition.


When creating an RDM for a virtual machine, it is necessary for ESX/ESXi to create an RDM pointer file for the virtual machine configuration file (VMX) to reference.
The datastore on which you are placing the pointer file must have a blocksize capable of supporting a filesize that is equivalent to the size of the RDM.  For more information regarding blocksize limitations, see the Configuration Maximums for VMware vSphere guide, or Block size limitations of a VMFS datastore (1003565)
This issue can also occur when the RDM is a supported file size. For example, you may have a problem recreating an RDM pointer file on a datastore with a 1MB block size when the RDM itself is 100GB. An RDM pointer file to the same RDM may have resided in that datastore previously, but the datastore (LUN) had been deleted so that it could be freshly created.
The error occurs when trying to re-create the RDM pointer file because it is not able to access the LUN in question. A rescan restores LUN access and the RDM can then be added.

Ensure that the APD situation is resolved, and retry adding the RDM to the virtual machine.
For more information, see Troubleshooting LUN connectivity issues (1003955).

Additional Information

 For more information on unpresenting a LUN, see Removing a LUN containing a datastore from VMware ESXi/ESX 4.x (1029786).

See Also

Update History

04/14/2011 - Included information about this issue occurring when the RDM is a supported file size. 13/3/2012 - Archiving the article 1031041 in favor of this one.

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