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  • 1.  How do I assign direct disk access to my RAID array?

    Posted Nov 24, 2009 11:51 PM

    I've just installed ESXi 4 and it's working pretty good.

    Right now I'm installing Windows Server 2008 R2 (x64)using the LSI Logic SAS driver (because Paravirtual isn't supported under Windows?).

    Anyways, how do I assign my Dell Perc 6/i's RAID array to my virtual machine? I want it to have direct/physical disk access.

    In vSphere the array shows up as "Parallel SCSI" but I can't figure out a way to assign it to my virtual machine.

    Thanks for any help!



  • 2.  RE: How do I assign direct disk access to my RAID array?

    Posted Nov 24, 2009 11:54 PM

    You have a few options

    1) Use a raw device mapping (RDM) - http://www.vm-help.com/esx40i/SATA_RDMs.php

    2) You could also try a generic SCSI device

    3) If you can dedicate the RAID controller exclusively to the VM then you can try VMDirectPath, but this would require that the host support Intel Directed I/O or AMD IOMMU.




    Dave

    VMware Communities User Moderator

    Now available - vSphere Quick Start Guide

    Do you have a system or PCI card working with VMDirectPath? Submit your specs to the Unofficial VMDirectPath HCL.



  • 3.  RE: How do I assign direct disk access to my RAID array?

    Posted Nov 25, 2009 01:28 AM

    Thanks for the reply!

    However, I'm still having some trouble.

    I can't seem to add a generic SCSI device (or I'm doing it incorrectly). When I try to add a SCSI Device to my VM it's grayed out and says "This device cannot be added to this Virtual Machine because: There are no non-disk SCSI devices available on the host"

    My CPU is an AMD Athlon II X2 250 which I don't think supports AMD IOMMU (I can't find any information on that), so that leaves me with the RDM option (which is probably what I want).

    I've read your link and executed the following command:

    /vmfs/volumes/4b0c1e10-7b240c51-54d2-001517a9bd09/RDMs # vmkfstools -z /vmfs/devices/disks/vml.020000000060022190b8a39a00126c766006927df3504552432036 RDM1P.vmdk -a lsilogic

    The error I'm getting is: Failed to create virtual disk: The destination file system does not support large files (12).

    My datastore is only 500 GB (and my RAID-6 is 4.5 TB), but is set to 1 MB blocksize so I can create VMDKs up to 256 GB, or so it says.

    Can you give me any other help?

    Thank you so much...



  • 4.  RE: How do I assign direct disk access to my RAID array?

    Posted Nov 25, 2009 02:08 AM

    For the generic device give this a try - http://communities.vmware.com/thread/155874.

    ESX(i) has a 2 TB (2TB - 512B) LUN limit so that might be the cause of your error with that. What sort of MB are you using? AMD IOMMU is a chipset feature.




    Dave

    VMware Communities User Moderator

    Now available - vSphere Quick Start Guide

    Do you have a system or PCI card working with VMDirectPath? Submit your specs to the Unofficial VMDirectPath HCL.



  • 5.  RE: How do I assign direct disk access to my RAID array?

    Posted Nov 25, 2009 02:13 AM

    I'm using an ASUS M4A78-E (AMD 790GX chipset).

    My main goal is to setup a file server VM (eg. Win 2k8) that has direct-access to my RAID array. I'd also like to use some RAID array management tools (eg. Dell OpenManage or LSI MegaRAID Storage Manager).



  • 6.  RE: How do I assign direct disk access to my RAID array?

    Posted Nov 25, 2009 03:12 AM

    You cant create an RDM for a disk larger than 2TB, as Dave said - this is the likely cause of your problem.

    Make smaller LUNs, and use the volume management in your guest OS to combine them.






    --Matt

    VCP, vExpert, Unix Geek



  • 7.  RE: How do I assign direct disk access to my RAID array?

    Posted Nov 25, 2009 03:22 AM

    Since a file server is not normally a high utilization type of disk why wouldn't you use 8MB block size and create larger vmdk disks?

    Also, wandered across this as well

    http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1010398

    Paravirtual SCSI adapters are supported on the following guest operating systems:

    Windows Server 2008

    Windows Server 2003



  • 8.  RE: How do I assign direct disk access to my RAID array?

    Posted Nov 25, 2009 10:42 AM

    Thanks so much for the replies everybody, and I apologize for all of my questions.

    I'll research creating multiple LUNs but does that mean I will have to recreate my array? (this isn't going to work for me since I have too much data on it) :smileysad:

    Also, I would have used a larger block size for my datastore but the ESXi 4 installation didn't seem to give me any options for that...