Migrating iSCSI VMK from vss to vds

[jlaco]

ESXi      5.0.0 469512

vCenter  5.0.0 455964

I am migrating standard switches to distributed switches in my lab and would like to know how to migrate the iSCSI vmk from the vSS to the vDS.  I have read through some articles and some vmware docs but haven't been able to find any useful info.  I have moved my management, vm and vmotion portgroups\vmks fine.  When I attempt to migrate the iSCSI vmk to the vDS portgroup via the Add Host wizard, I receive the following message saying that the vmk is still bound to the iscsi adapter. 

"  This operation cannot be done while the vmkernel network adapter vmk2 is being used by iSCSI adapter.  Remove the VMKernel network adapter

from the iSCSI adapter to successfully complete this operation. "

Do I really need to unbind the kernel from the iSCSI adapter?  Do I need to do this manually somehow?  If this is the case, what are the general steps to getting the iscsi vmk migrated successfully?

One other question....  I have been reading that it is not a good idea to have vCenter virtualized and using vDS and in fact Vmware does not support it.  Even though it is a waste of nics, should vCenter have it's own vss's?

Thanks!

[Virtualinfra]

Refer this document.. were it clearly explains about the iscsi migration from v Standard switch to v distributed switch.

http://www.vmware.com/files/pdf/vsphere-vnetwork-ds-migration-configuration-wp.pdf

[jlaco]

This is one of the documents I read before posting my question.  I get the error after completing one of the steps in this document.  Do you have any other insight regarding the error message and why I am receiving it and possibly some next steps?  Thanks for your reply.

[Anfernee86]

I had the same error/scenario and this is what I did to get it working.

1) I put the host in maintenance mode (optional but wasn't sure of the outcome)

2) went into the iSCSI vmhba in Storage Adapters --> Properties --> Network Configuration tab and removed the two vmk's I created on the vSS in order to configure iSCSI multi-pathing.  Once you remove the vmk's, your host will still see the iSCSI datastores, but you just won't have multipathing enabled (I went from 2 devices - 4 paths to 2 devices - 2 paths). 

3) went to Home --> Inventory --> Networking and had all my dv port groups pre-created. Right clicked on the dvSwitch and clicked Manage Hosts. 

4) Clicked the check box for the one host I am working on (in maintenance mode) and did the migration as documented in the above mentioned pdf. 

5)I went back into the iSCSI vmhba in Storage Adapters and added the two new vmk's (which should have the same vmk number as was on the vSS). 

6)repeat on the other hosts one at a time

Sorry I had to type this out quickly.  Let me know if I wasn't clear on a certain step. 

[jlaco]

Thanks for your reply Anfernee86.  I'll give it a shot when I get some time!

[autoxr]

Just ran through this in my lab/test environment.

I went about the cutover slightly differently from what is already posted and was able to make the change without causing an iSCSI outage.  Also I'm using Jumbo Frames.

Home > Networking

1. Precreate new vDS and configure it for Jumbo Frames.

2. Configure the Uplink Port group with the pNICs you want to use (I chose not to reuse the VSS NICs and had extra NICS available for my new vDS)

3. Configure the iSCSI Port group.

4. Click on the new vDS > Summary > Manage Port groups > Teaming and Failover > configure the new iSCSI port group to use the proper pNIC.  You need a one to one relationship to keep in best practice.  Also in the later steps, you won't see the new iSCSI VMK show up as an option to associate with the iSCSI adapter unless you're one to one.

At the host > Configuration > Networking > vDS

1. Click Mange Virtual Adapters > Create a new VMK for iSCSI.  Have a new iSCSI IP address ready to input. Also note that you'll need to make sure that the new VMK can authenticate to the iSCSI LUNS.

2. Associate the new VMK to the new vDS/Port group you created earlier.  Take note of the new VMK number.

3. After clicking OK, go back in and configure the VMK for Jumbo Frames.

At the host > Configuration > Storage Adapter

1. Click on the properties of the iSCSI adapter and click on Network Configuration.

2. Add/associate the new vmk you created with the iSCSI adapter.

3. You'll notice that the path status is not green.  Click Close and you'll be prompted to rescan.

4.  After the rescan is done, go back into the iSCSI adapter properties and you'll see the new VMK lit up.

5. At this point, you can remove the old VMK.

6. At this point, remove the old iSCSI VSS NIC uplinks and test.

I had RDP sessions open to VMs on the affected iSCSI datastores with the clock opened up and watched the second hand keep ticking while I made the change.  No Down time.

Note: I am using the new vDS I created for vmotion and iSCSI since both benefit from Jumbo Frames.

After make the change I notice that I'll have the following benefits if I need to add another host.

Adding each new host via the VSS way.

1. iSCSI -  Create a VSS for iSCSI, configure it for Jumbo Frames, create VMK and configure it for Jumbo Frames, Associated the new VMK with the iSCSI storage adapter

2.  vMotion - Create a VSS for vmotion, create VMK

Add new hosts via the VDS.

1. iSCSI - Add the host to vCenter, add the pNICs to the uplinks, create new VMKs iSCSI and set for Jumbo Frame, Associate the new VMK with the iSCSI storage adapter.

2. vMotion - Similar to above minus the iSCSI adapter association.

Using the vDS method, I save a few steps creating/configuring new VSSs for each new host.