VMware Solutions Discussions

iSCSI LUN and group initiator type for vSphere RDM


     Im trying to use RDM (iSCSI) from our FAS2050 to our new exchange 2010 VM (Windows 2008 R2) for databases (OS is on NFS VMFS).

So, i have to create an initiator group, and throw both of my ESXi in it, in that initiator group i have to choose type, which one should i do, Windows or VMWare? (ESXi is vmware, but RDM will connect to Windows guest,thats why its kind of confusing).

Also, the same question when creating LUN for iSCSI that will be used for this RDM, it also asks me for type (windows, since it is an RDM to windows box, or vmwre, since ESXi does RDM proxy).




The igroup type should be vmware and the lun type the guest os... the windows lun type will map to the vmware igroup.

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This is a very interesting question, because I see the LUN type set to "Windows," "Windows 2008," and "VMware" at different customer sites for RDMs to Windows VMs, and all 3 types seem to work fine.  I tend to see more "VMware" than "Windows," even though the LUNs are being passed thru to Windows VMs.  This is probably since the GUI only shows the VMware Initiator Groups when you select "VMware" as the LUN type.  My question is, does it really matter?  What exactly is done on the NetApp side by choosing a LUN type of "VMware" as opposed to "Windows" as opposed to "Windows 2008"?  Anything special under the hood going on?


I think I sets file system alignment correctly which will have negative input on performance if set to wrong OS, but I may be wrong

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I kind of wondered about that.  Since the vSphere Client automatically aligns VMFS volumes optimally, and Windows 2008 automatically aligns partitions optimally, I'm curious what (if any) difference would occur between selecting "VMware" and "Windows 2008" as the LUN type.  For Windows 2003 and earlier, which don't align themselves automatically, I can see a benefit to selecting "Windows" for those LUNs (unless the administrator already manually aligned them with the MBRALIGN tool).  Assuming all LUNs are already properly aligned (via MBRALIGN or vSphere Client or Windows 2008), I wonder if there is any net effect to this setting?


The igroup type should be vmware and the lun type the guest os... the windows lun type will map to the vmware igroup.

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Ok, this is what I have done: I created a vmware initiator group and throw both esxi hosts in it. Then using system manager I created a LUN, put windows 2008 as a type. But now I can not assign this LUN to the initiator group, the available list for the initiators is empty. What's going on?


System Manager will not allow you to assign an igroup to a different type of lun (VMware igroup to Windows GPT LUN) You will need to map that in Filer View.


Got it, Thanks,

Filer View did it (vmware igroup to windows 2008 lun type).

Wow, NetApp, i hope somebody fixes that in next version of System Manager. (at least an error message would be helpful)


Reviving an old thread...

While this doesn't work in system manager...it does works like a charm in the OnCommand System Manager (I'm using 2.0).  You can assigns LUNS of type X, to igroups tagged  OStype Y by checking the "Show All Initiator Groups" box in the Create LUN wizard.

Or you can do it from the command line with the lun map lun_path initiator_group command. 



with RDM you should use the type of the guest operating system.

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