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phantom024Flag for United States of America

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Add existing VMFS datastore to new ESX host

I am setting up a small ESX datacenter for my company.  The setup consists of a Dell PowerEdge 2950 connected via iSCSI to a Dell PowerVault MD3000i.  The first Dell 2950 ESX host connected to a 1TB LUN on the MD3000i and created a single VMFS volume without any problems. To do this I added the 2950 (named esx01) to a host group on the MD3000i, and granted access for the host group to the LUN.  I then rescanned the iSCSI storage adapter and the LUN was identified right away.  I then added the storage to the host and created a datastore with a VMFS volume named esx-disk01.  I have since added a few VMs onto the host and everything is running well, I even tested path failover from the 2950 to the md3000i and it is working wonderfully.

I am now wanting to add an additional Dell 2950 to the ESX datacenter, and even a third after this, but I am taking this one server at a time.  I have succesfully installed ESX Server 3.5 on the new 2950 (named esx02) and added the new ESX host to my Virtual Center server in the same Datacenter as esx01.  I added esx02 to the host group on the MD3000i so that it would have access to the LUN containing the VMFS volume esx-disk01.  I then go to the Configuration tab of esx02, click on Storage Adapters, and rescan the iSCSI Software Adapter and successfully see the LUN that contains esx-disk01. It is the next step I am having trouble with.  How do I get esx02 to use the datastore containg the VMFS volume esx-disk01? I clicked on Storage under the Configuration tab and went to Add Storage. As I continue through the Add Storage wizard I can select the LUN containg esx-disk01 but it wants to format it and create a new VMFS volume.  I do not want to format the volume, I want to retain the VMs that I created already. Where am I going wrong? I want to be able to connect both hosts to the same 1TB VMFS volume, esx-disk01, that was created by esx01 on the mD3000i.  Any and all help is greatly appreciated.
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agriesser
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Are you perfectly sure that you are seeing the same LUN on both ESX servers?
When you did the rescan, did you also check the box to rescan new VMFS filesystems?

When you click on "Inventory" -> "Datastores" in your Virtual Center GUI and click on the datastore in question you should see the number of hosts connected to this datastore. What number does it show?
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1. I am asuming that it is the same LUN because, there are only 2 LUNs on the MD3000i a 1TB and a 1.4TB with LUN IDs 1 and 2 respectively, the LUN that is being found by esx02 is 1TB in size and has a LUN ID of 1.

2. Yes, I was sure to check the "VMFS filesystems" when I did a rescan.

3. Virtual Center only shows 1 host connected to the datastore.

Do I need to shutdown all the Guest VMs running on esx01 that are stored on esx-disk01 when I do the scan?
No, you do not need to shut down the Guest VMs for that. Not even when using iScsi.

You could try to enable Resignatures on the VMFS volumes, see the end of this posting for information about how to do this.

I guess you already followed Dells Deployment Guide for ESX servers?
http://www.dell.com/downloads/global/solutions/md3000i_esx_deploy_guide.pdf

Oh, and, could I please see the output of `esxcfg-mpath -l` on both ESX hosts?

If that all doesn't help, I think you're affected by this one:
http://kb.vmware.com/kb/6482648

To get it working again, follow these steps:

In the Virtual Infrastructure Client:

    * Select the ESX host
    * Select the Configuration tab
    * click on Advanced Settings
    * Select LVM in the left pane
    * Set LVM.EnableResignature to 1 and click OK
    * Click Storage Adapters
    * Click Rescan in the top right
    * Click OK
    * Click on Storage (SCSI, SAN and NFS)
    * The volume should now appear as snapshot-xxx
    * Right click and select Rename from the context menu
    * click on Advanced Settings
    * Select LVM in the left pane
    * Set LVM.EnableResignature back to 0 and click OK


On the remaining ESX hosts:

    * Select the ESX host
    * Select the Configuration tab
    * Click Storage Adapters
    * Click Rescan in the top right - Click OK
    * Click on Storage (SCSI, SAN and NFS)
    * The volume should now appear


Ok, I may have gotten myself in trouble here. I attempted the above solution and esx02 was able to see the volume as a snapshot volume, however I could not rename it, I recieved an error stating that the given name was in use and to try a different name.  Obviously I was unable to use the datastore when esx02 saw it as a snapshot volume. I figured I would try the process again by removing the snapshot storage volume from esx02. Upon removing the snapshot volume, it also removed the volume esx-disk01 being used by esx01. Now all VMs that were running on esx01 are greyed out and listed as inaccessible. I can still go into Inventory-->Datastores and see esx-disk01 and under the Virtual Machine tabs it lists all the VMs that were present, under the Hosts tabs it show nothing.  No matter what I do now, both hosts can see the 1TB LUN in the Storage Adapters section but neither will attach to it and list it in the Storage section, the only thing available is the local datastores from the internal hard disks of each ESX host. I cannot get either host to reconnect to esx-disk01.  Everything on the MD3000i is fine and all paths are working but it just wont recognize the VMFS volume on esx-disk01.  I have upped the points on this to 250 because I really have got myself in trouble.  Thanks in advance
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agriesser
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Were you able to get access the LUN again?
Thank you for your assistance.  Fortunately there were no production VMs on the setup, They were copies of machines made to test in a non production environment first.

I decided to start the process over since the data could be lost without harm.  I took your advice and created a small testing LUN in addtion to a large LUN for usage.  The small LUN then was formatted and discovered by all esx hosts (I went ahead and put the third in the mix).  Then I reformatted the large LUN but had the same problem that the first esx host attached but the other 2 refused to recognize the presence of the VMFS volume.  After digging through the KB articles at vmware I attempted to disable snapshot luns throught the advanced settings under LVM.  After snapshot LUNs were disabled, all ESX hosts discovered the VMFS volume and everything has been working since.  Thanks for the guidance
Thanks for the help.  Since the data was not production I started over and ran into the same issue but this time I setup a small testing LUN that you suggested.  Your advice was on the right track, I think I just messed something else before i attempted your advice.
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quadrumane

You should ALWAYS call Dell technical support for storage when such an problem arises

We've got this problem on ESX 3.5 update 2.   We had to delete the host group, then recreate it so ESX was seeing the storage.  You should never try to use resignature if you're not sure about what you're doing.  Call Dell or Vmware it this happens.