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LUN filtering mechanism during RDM creation (1010513)

Details

When you create a virtual machine with an RDM, vCenter Server by default excludes LUNs that are already used for VMFS datastores or RDMs from the list of candidate target LUNs. Only unformatted LUNs are displayed for your selection.

This LUN filtering mechanism helps prevent LUN corruption that might occur if these conditions are not met:
  • The same LUN cannot be used for a VMFS datastore and RDM simultaneously.
  • Two virtual machines cannot have access to the same LUN using two different RDM mapping files.

Solution

If you need virtual machines to access the same raw LUN, they must share the same RDM mapping file. For details on this type of configuration, see:

The config.vpxd.filter.rdmFilter and config.vpxd.filter.vmfsFilter configuration options in the vSphere Client control the LUN filtering mechanism. The options are set to true by default, but can be individually set to false when you need to turn off any of the filters.

However, you should not turn the filters off unless you have other methods to prevent LUN corruption.

Note: If you are upgrading your environment, it is important to check the values after the upgrade as the values can return to their default setting.

To turn off any of the filters:

  1. In the vSphere Client, click Administration > vCenter Server Settings > Advanced Settings.
  2. Depending on your needs, add one or both of these key and value pairs:
    • config.vpxd.filter.rdmFilter; false
    • config.vpxd.filter.vmfsFilter; false

  3. Click Add, then click OK.
If you now create a virtual machine with RDMs, all shared LUNs are displayed as RDM candidates even though they are already being used on a different ESXi/ESX host.

To turn the filters on again, set the values to true.

Note: For related information, see:

Update History

10/01/2010 - Added note:If you are upgrading your environment, it is important to check the values post upgrade as the values can return back to their default setting.

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