I'm sorry if this has been asked before.

We are planning to attach a local SAS disk to a VM, so the VM can access the disk directly. We're using VMware ESXi 4.

I have heard that this can be done with SAN LUNs. But how about local disks?

Our storage controller is HP SmartArray P400.

Update: I tried adding the disk, bur the Raw Device Mapping option is greyed out. Are there any other way?

  • Did you create a partition on the disk? – Massimo Aug 31 '09 at 10:27
  • Not yet. It's a fresh install of ESXi. ESXi automatically format it as VMFS, and label it as datastore2. I've deleted datastore2 from the list of datastores. – Arie K Aug 31 '09 at 12:04

No problem, this can be done easily using 'raw device mapping' or by using VMFS on the disk - plus the P400 has a native driver in v4 too. You're onto a winner :)

  • I tried, but the "Raw Device Mapping" option is greyed out. Are there some hidden options? – Arie K Aug 31 '09 at 9:29

As Chopper said, you can use RDM for direct access to the hardware, however, it may be more beneficial to format the SAS drive as a VMFS, create a vmdk file on it, and map that as an additional virtual disk. This way you'll take advantage of the encapsulation, making it easy to move, clone, snapshot, backup, etc.

I'm sure you have your own reasoning, though, e.g. performance or some other means of testing.


I did a quick search regarding your issue and I hope this could help you.


  • Whilst this may theoretically answer the question, it would be preferable to include the essential parts of the answer here, and provide the link for reference. – Mark Henderson Dec 11 '13 at 2:38

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