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ESX host shows a purple diagnostic screen and the error: Unable to handle kernel NULL pointer dereference at virtual address 00000004 (2004208)


  • An ESX host crashes and displays a purple diagnostic screen with the following information:
Unable to handle kernel NULL pointer dereference at virtual address 00000004
  • At the time of the host crash, there are virtual machines connected to the host's SATA CD-ROM device and attempting to access it.


This article describes a specific issue. If you experience all of the above symptoms, consult the sections below. If you experience some but not all of these symptoms, your issue is not related to this article. Search for your symptoms, or Open a Support Request.


This crash occurs due to an issue with the ata_piix driver.


This issue occurs when a virtual machine tries to access its host's SATA CD-ROM drive. This results in the host crashing.

This is a known issue in ESX 3.5, and has been observed in ESX 4.0. This issue has not been observed on ESX/ESXi 4.1. You can try upgrading to the most recent version of ESX, available in the VMware Download Center.

If you encounter this issue with ESX 4.0 or 4.1, file a support request with VMware Support and note this KB article ID in the problem description. For more information, see Filing a Support Request in My VMware (2006985) or How to Submit a Support Request.


There are several methods which can prevent this issue from occurring on ESX hosts:

  • Disable the SATA CD-ROM:

    • in the BIOS,
    • by physically disconnecting it,
    • by preventing the "ata_piix" driver from loading.

  • Move the SATA CD-ROM to a motherboard port or an add-on card port that uses a different driver.
  • Disconnect the physical SATA CD-ROM device from any virtual machines on the host
  • Attach a different type of CD-ROM device (such as USB or PATA) to any virtual machines on the host.

Note: The SATA CD-ROM drive can still be accessible by the ESX host itself.


cannot-use-cd-dvd-driveĀ  purple-diagnostic-screen

See Also

Request a Product Feature

To request a new product feature or to provide feedback on a VMware product, please visit the Request a Product Feature page.


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