HCC
Enthusiast
Enthusiast

RDM WWNs not visible on san switch port

Hi,

I have added a RDM disk to one of my VMs. My server has QLE2460 FC HBAs.

When I created the RDM, it associated a path of vmhba:3:0:0 LUN 0 to one of the HBA that is SAN

attached. I know the physical HBAs are working as I can see my storage LUNs. I

went into the settings of the VM and turned on the NPIV and generated WWPNs which I believe

you are suppose to do. I checked our Cisco MDS9500 SAN switch and the only WWNs showing

are the physical HBAs but not the virtual ones I generated.

Can anyone tell me what I am doing wrong or if I am missing a step? I can not zone space to a VM if

I can not see the WWN of the VM.

Thanks

13 Replies
weinstein5
Immortal
Immortal

using an RDM that will be hidden form your Cisco switch - the switch in the configuration you have will only see the physical HBAs - the RDM simply redirects the vmkernel to the raw LUN -

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HCC
Enthusiast
Enthusiast

Thanks for the reply.

Is this an incorrect setup then? how do I assign a LUN to the VM ? Typically we would mask SAN space to a particular host's WWN granting it permission to access the LUN. What should I have done ro how do I associate the space to the VM?

Thanks again.

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weinstein5
Immortal
Immortal

You are heading down the right path - you will attach an RDM to your VM which will allow you to access a raw lun on the SAN - follow the below instructions -

Mapping a SAN LUN For virtual machines running on an ESX Server host, instead of storing virtual machine data in a virtual disk file, you can store the data directly on a SAN LUN. This is useful if you are running applications in your virtual machines that must know the physical characteristics of the storage device. When you map a LUN to a VMFS volume, VirtualCenter creates a file that points to the raw LUN. Encapsulating disk information in a file allows VirtualCenter to lock the LUN so that only one virtual machine can write to it. |Note This file has a .vmdk extension, but the file contains only disk information describing the mapping to the LUN on the ESX Server system. The actual data is stored on the LUN. You cannot deploy a virtual machine from a template and store its data on a LUN; you can only store its data in a virtual disk file.|

To map a SAN LUN

1

From the Select a Disk page, select Mapped SAN LUN.

2

Click Next.

3

Select a LUN for the raw disk.

4

Click Next.

5

Select a datastore onto which to map the LUN.

6

Click Next.

7

Select a compatibility mode, either physical or virtual.

Physical compatibility mode allows the guest operating system to access the hardware directly. Physical compatibility is useful if you are using SAN-aware applications in the virtual machine. However, a LUN configured for physical compatibility cannot be cloned, made into a template, or migrated if the migration involves copying the disk.

Virtual compatibility mode allows the virtual machine to use VMware snapshots and other advanced functionality. Virtual compatibility allows the LUN to behave as if it were a virtual disk, so you can use features like disk modes. When you clone the disk, make a template out of it, or migrate it (if the migration involves copying the disk), the contents of the LUN are copied into a virtual disk (.vmdk) file.

Subsequent screens offer different options, depending on your choice.

8

On the Specify Advanced Options page, you can change the virtual device node and click Next.

9

On the Ready to Complete New Virtual Machine page, review your selections. Click Finish to complete your virtual machine, or optionally perform additional configuration (see ).

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HCC
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Thanks for the instructions.

I have a couple of questions, on the SAN side, do I Mask the LUN to the physical HBAs of the ESX hosts ? Do I need to enable NPIV or generate WWNs ?

Thanks again.

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weinstein5
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YOu would need to mask the lUN on the SAN side to thephysical HBAs but rememebr if you want to vmotion this vm you will to amke sure both the raw LIN and the LUN housing the VMFS and RDM is seen by bth esx hosts - this is true for DRS and HA as well-

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HCC
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So, where does the NPIV Option come in to play or does it ? I enabled the NPIV and generated virtual WWNs. Was that necessary in this case ? The physical box is using 2 single port QLogic HBAs. Should I remove the Virutal WWNs and disable NPIV again or do I need it still ?

Thanks

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nptbb01
Contributor
Contributor

I hope someone answers this, I have the same problem/question

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HCC
Enthusiast
Enthusiast

It looks like I have it working now. I turned off the NPIV option and masked the LUN to the physical HBAs of the physical ESX Server(s). Once this is done then I had to rescan the Storage Adapters in VirtualCenter Server. Now I see a new LUN. Now go to the VM and add the drive and pick the new LUN as the RDM disk. It should show up in your VM now. (you might have to rescan for disk in Windows if you don't see it)

If you created the hard drive on the VM first as I did, you probably ended up with a RDM disk called scsi0:0 of 0MB, if so, delete this drive from your VM as it is obviously has no space to use. Also, if you reboot the VM and it will not let you start it up giving you an error that says in can't find scsi0:0 ... then you have to edit the vm.vmx configruation file and change the setting ffrom scsi0:0 Present = TRUE to scsi0:0 Present = FALSE.

I am using a 2U IBM server in my configurations for both of my ESX Servers. If you are using a BladeCenter or something like that it may differ slightly.

Hope this helps.

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kjb007
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There are multiple ways of adding a raw device to a vm. An RDM in physical or virtual compatibility mode is really zoned to the ESX hba's as you're already aware. That means of adding the disk has nothing to do with NPIV.

When you do generate WWPN for the vm's, then yes, you do your masking of the LUNs to the WWPN of the vm's that you generated. You will have to make sure that your fiber switch supports NPIV. I know brocade requires a certain version to enable NPIV, not sure if the MDS you're using requires the same. Once done, you should be able to see the WWPN of the vm that you just enabled NPIV on. If you don't see the port in a selection menu right away, then enter it manually, if you can. I don't have a lot of experience with MDS, so I can't give you specifics here, but you zone/mask with the WWPN of the vm's just as you do any other server.

-KjB

vExpert/VCP/VCAP vmwise.com / @vmwise -KjB
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HCC
Enthusiast
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Hi, I did not generate WWPN. I did at first but the Cisco could not see the WWPN I generated. When I just masked the LUN to the physcial HBAs, it should up in the storage list as a new LUN. When I added a 2nd drive and chose physical RDM, it gave me a list of drives to choose from so I just chose the new LUN from the list....not WWPN generated and no NPIV enabled.... The VM say the disk so I assumed that is correct.

If this is incorrect, please let me know so this can be fixed before the VM goes into Production.

Thanks

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kjb007
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Yes, when you mask to the physical esx hba's, you are in a way using ESX as the array for the vm's. When you use the WWPN, then there's no middle man and you mask directly to the vm's themselves. So, the difference in this case is who is presenting the disk, with NPIV, the array presents the disk, with the other way, the ESX host presents the disk to the vm. Also, make sure your HBA's support NPIV as well, and that there isn't something additional required to enable it.

Hope that makes sense.

-KjB

vExpert/VCP/VCAP vmwise.com / @vmwise -KjB
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sakthi0708
Contributor
Contributor

Hi,

I am also facing a similar problem. i am not able to see the Virtual WWPN generated by ESX, in Brocade 5000 SAN switch. i have a doubt whether i forgot some steps?

I installed ESX, created VM with Storage as RDM, physical. then generated WWPN from VM Options. vmkernel log message says the creation of WWPN failed. also these WWPN are not visible in SAN Switch.

I tried ESX 3.5, 3.5 U2, 4.0 beta. but the result is same.

All that i want to know is what is the cause for this issue? any help is appreciated. are there any known incompatibility?

or simply what should i change (Hardware) to make this NPIV work.

If you have solutions, please help me vsakthivel_cs@yahoo.com

CONFIGURATION DETAILS:

HBA: QLE2462 / 4 GB/ Max NPIV Ports = 64 / Firmware version 4.00.26 , Driver version 8.01.07

ESX: esx-3.5 Update2, Build 110268

Server: DELL Power Edge 2950 / 8 GB / Intel(R) Xeon(R) CPU E5430 @ 2.66GHz

The SAN switch has NPIV Enabled. here is the configuration details;

Switch information: Brocade 5000

Kernel: 2.6.14.2

Fabric OS: v6.0.0b

Made on: Fri Jan 18 21:32:16 2008

Flash: Wed May 28 00:39:57 2008

BootProm: 4.6.6

--

Thanks in Advance,

Sakthivel.V

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sakthi0708
Contributor
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All that i want to know is what is the cause for this issue? any help is

appreciated. are there any known incompatibility?

No hardware incompatibility

or simply what should i change (Hardware) to make this NPIV work.The problem is with zoning. zoning should include the RDM lun which you mapped to the newly created VPort

The Vmware ESX works in the following concept;

when a VM (NPIV enabled) is created, it should be installed in RDM Lun. this is required because this is the way vmware ESX uses NPIV.

When a VM is powered on before VM POST it scans the physical HBA. if ESX identifies a LUN which is zoned with the Vport (Virtual WWPN generated by ESX {done from VC/VI client after VM creation}) then it actually creates a Vport (Virtual WWPN) and login into FC fabric.

So, you have a RDM Lun mapped to VM, and the LUN is masked to this VM, and the FC soft zoning should include;

ESX host WWPN, Virtual WWPN (Vport), Virtual WWNN

now power on the VM, and the magic happens. the virtual port is displayed in Brocade Switch.

Hope this helps for any one who face the same issue in future.

If you need more help just PM me. Smiley Happy

-Sakthivel.V