VMware ESX 4 -> Failed to update disk partition information.

After creating a new LUN on a Dell MD3000i, I wanted to add the new iSCSI LUN to my ESXi server. Everything went fine, the LUN was presented and the Add storage wizard has found the new LUN. But when i wanted to complete the wizard, the following error came up:

Now if you go on the Internet a search around you will find several references to this issue. Most if not all of them tell you to:

1. Use fdisk on the /dev/sd[a-z]* device. Create a partition with type 0xfb.
2. Format the VMFS datastore using
vmkfstools -C vmfs3 vmhbaI:T:L:P
In this example, I corresponds to the initiator of the VMware host bus adapter, T corresponds to the target number of the disk, L is the LUN number, and P is the partition number of the newly created partition.

3. Reboot ESX server

This is not always required, It may be just a hickup in your ISCSI registration on the ESX servers. Here is how I fixed mine and it worked with out any reboots or major adjustments.

Steps to take first before following the CLI instructions:

  1. Go create another 5Gb LUN on Power Vault.
  2. Set the access group assigned to new LUN to allow ESX servers
  3. On ESX Host GUI go back to configuration menu and select Storage Adapters menu
  4. Select your ISCSI Software Adapter from Storage Adapter list and select “Rescan” (even if you see your LUN)
  5. Go back to the Storage menu and select add storage, select Disk/LUN and follow through the menus to mount and format the 5gb LUN and it should go through now.
  6. Remove the 5gb LUN from the ESX Storage menu.
  7. Remove the 5gb LUN from Dell Vault.
  8. Go back to your ESX and rescan HBAs and make sure the 5gb LUN is gone and you see your original LUN you want to mount.
  9. Go back to the Storage menu and select add storage, select Disk/LUN and follow through the menus to mount and format the  LUN and it should go through now.

If this does not work then change the access to the LUN on the vault to a new access group. Rescan for LUN on ESX then go reset the LUN back to the original access group you want to use and then rescan again from ESX.  Try to remount LUN and format. This should now connect and no errors should appear. If you still are getting errors then you may have other issues and you can now try the CLI method or call in support.

Good Luck, I hope  this helps a few of you out there from dealing with production systems and not wanting to spend all day VMotioning, reboots and such.


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3 Responses to “Error during the configuration of the host: Failed to update disk partition information”

  1. Joe Diaz says:

    Steps 4 and 5 resolved our issue. The new LUN was showing up as 2TB even after recreating it as 1.8TB. Thus, the refresh option didn’t help until I performed the rescan.

    Thanks much for your help because VMware’s site doesn’t post this.

  2. Vina says:

    At last, sonmoee who comes to the heart of it all

  3. http://www./ says:

    Sounds like you’re cranking it out with those unpredictable characters! Good job, Sydney. I just broke 14K, which I consider a pretty good place for someone in my condition . I don’t leave the couch much, so that’s good for writing (as long as I can stay awake).

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