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How to properly unpresent/remove LUN from Vmware.

My environment: EQL PS4000XV. VMware 4.1 on 3  hosts. MEM kit installed and activated on all three hosts. HIT/ASM not activated for vSphere.

I have a LUN (volume) created and access setup based by iqn. I need to delete this volume to recapture some space. Since it's presented in VMware and formated for VMFS, what's the recommended best practice for gracefully removing this LUN (volume) ?

Verify it's not attached to any gues vms.

Delete from a single VM host 

remove IQN access on EQL volume

rescan HBA's on all hosts

confirm LUN/volume is gone

delete volume in EQL 

Looking forward to your feedback.

H.

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15 Replies
Moderator
Moderator

Re: How to properly unpresent/remove LUN from Vmware.

For the most part you are correct. Below is a are the steps I would recommend following.

1. Verify no I/O is going to the volume.

2. Remove datastore from hosts.

3. Unmount volume from hosts.

4. rescan storage adapter inside ESX.

5. Remove IQN access inside array.

6. Set volume offline.

7. Delete volume.

Let me know how it goes.

Kenny K.

Download the Dell Quick Resource Locator app today to access PowerEdge support content on your mobile device! (iOS, Android, Windows)

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8 Krypton

Re: How to properly unpresent/remove LUN from Vmware.

Thanks for the quick reply. Could you explain what you mean by unmount volume? Also, i'm under the impression that once i remove a LUN from one host, the removal will replicate across all hosts since it's technically shared storage. The same idea applies when you create a new volume, you only do it once on a single host, and rescan HBA's on all other hosts to see the newly added LUN.

Also, i would imagine i would need to remove the datastore then REMOVE IQN access on the array BEFORE i rescan storage on all hosts. If the IQN is still part of the array, the rescan would still pick up the volume on the hosts for which IQN access is configured and granted...at least that's my thought and I could be wrong.

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8 Krypton

Re: How to properly unpresent/remove LUN from Vmware.

vSphere 4 doesn't have an unmount option, so ignore that step.

So, from Kenny's post:

1. Verify no I/O is going to the volume.

2. Remove datastore from hosts.

3. rescan storage adapter inside ESX.

4. Remove IQN access inside array.

5. Set volume offline.

6. Delete volume.

Member since 2003

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8 Krypton

Re: How to properly unpresent/remove LUN from Vmware.

Thanks for the clarification Dev. I still don't quite understand why i would rescan storage on ESX BEFORE removing the IQN's on the volume inside EQL. If the IQN's are still active, once i rescan i would imagine ESX attempts to make the iscsi connection to already deleted volume.

But thank you for the quick replies nonetheless and I'll give this a shot.

Best Regards,

H

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8 Krypton

Re: How to properly unpresent/remove LUN from Vmware.

The short steps are:

- verify/double check so you know for sure which volume you're wanting to delete

- offline the volume in the EQL group manager

- rescan the storage adapters in VMware and verify the correct disk disappeared (if the wrong one disappeared you did kill the VMs on it, but at least you can online the disk again to bring it back (instead of having deleted the volume already))

- delete the volume from the EQL group manager

Member since 2003

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8 Krypton

Re: How to properly unpresent/remove LUN from Vmware.

So this is a completely different method that you've have confirmed works just as well ? Thanks!

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Moderator
Moderator

Re: How to properly unpresent/remove LUN from Vmware.

I believe the first part of the last post from Dev Mgr was to removing the vms from the volume so there is no activity and then deleting the datastore from ESX and then you would move to the EQL Group Manager to offline and delete the volume.

Kenny K.

Download the Dell Quick Resource Locator app today to access PowerEdge support content on your mobile device! (iOS, Android, Windows)

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Highlighted

Re: How to properly unpresent/remove LUN from Vmware.

This nice thing about deleting the datastore in ESX is just a cleaner way of doing it.  You're removing the datastore from the SQL database.  As opposed to just yanking it out from underneath the servers.

 The way I use is:

1.)  Move any VMs

2.)  Delete the datastore in the VCS GUI

3.)  Refresh the storage views in the ESX servers.  

        To make sure they have updated info that the datastore is no longer there.

4.)  offline the volume in the EQL GUI.  

5.)  Rescan the storage adapters on the ESX servers.

6.)  Delete the volume in the EQL GUI

If you don't offline it at least first, then the static mappings on each ESX server will constantly attempt to re-login to that volume until the ESX servers are rebooted.

Regards,

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#IWork4Dell
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Re: How to properly unpresent/remove LUN from Vmware.

There it is. Thanks dwilliams. The key difference being Refresh vs Rescan and making sure I offline the volume. Great. Thanks!

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