Change iSCSI Controller of virtual vCenter Server

[ALF4]

I have a possible solution to this but wondering if anyone had a better idea?

I have a vCenter server which is a virtual machine hosted on a VMware 5.0 U3 platform (4 Host HA cluster). The SCSI controller for this server is an 'LSI Logic SAS' and I would like to change this to 'Paravirtual'.

Now the procedure for this is to add a 1MB (VM best practice says 1GB why?) disk on a different iscsi bus using the paravirtual SCSI controller, then shutdown the VM, remove 1MB disk and change the original SCSI controller type to Paravirtual. Simples Right?

Ok, so you add you 1MB disk on a paravirtual SCSI controller and shutdown the VM but wait a minute... its running you vcentre! DOH! now you cant make any changes and your vcentre is down... mmmm. OK log into the host running the vCenter server and make the changes there right? wrong! The host is being controlled by the vcentre server and VMware gives you a lovely error message that "resources for this virtual machine can only be done from <Ip_address of vcentre server you just shut down>.... How infuriating! At least you can power-on you vCenter server I guess :smileyangry:

So your vCenter server is now backup at least and you just spent ten minutes and caused a brief outage to you vCenter server with no result.

The only way I can get arround this is by creating a clone of my vCenter server and during the process use the 'Edit Hardware Settings' Experimental to change the SCSI controller. But really?

Can anyone else help me think around this issue?

All help greatly appreciated

ALF4

[a_p_]

>>> resources for this virtual machine can only be done from <Ip_address of vcentre server you just shut down>....

The steps you mentioned are basically correct. Add another virtual disk with the new controller type to force the guest OS to load the drivers. Then shut down the guest and modify the settings by connecting the vSphere Client directly to the host. With the above mentioned message, I'd assume you enabled "Lock Down Mode" for the host, which - in this case - has to be disabled prior to shutting down the vCenter Server.

André

[a_p_]

... the 1GB virtual disk mentioned as a best practice is most likely due to the fact that a 1GB LUN is the smallest size provisionable on most storage systems.

André

[ALF4]

Many thanks for your replies... couple of things, the procedure for changing the SCSI controller to "paravirtual" works with all other virtual machines just not with the vCenter server as once shutdown the only way to edit the hardware settings is by connecting directly to the host the vCenter server is running on and making the changes there. However, this fails with the error mentioned above. To confirm the host is NOT in lock down mode.

[a_p_]

If lock down is disabled and you still cannot logon to the host directly, there are actually only two reasons I could think of:

1. A firewall blocking traffic
2. An old vSphere Client version (this can happen if you did update/patch the hosts, but not vCenter Server)

André

[King_Robert]

To change a virtual machine's SCSI controller when the guest operating system is already installed:

1. Power down the virtual machine.
2. Right-click the virtual machine and click Edit Settings.
3. Click the SCSI controller.
4. Click Change Type.
5. Select the controller type and click OK.
6. Click OK to finish editing the properties of the virtual machine.
7. Power on the virtual machine.

If the virtual machine fails to boot:

1. Power down the virtual machine
2. Change the first controller back to the original SCSI controller.
3. Add a new hard disk. When choosing the Virtual Device Node, select SCSI (1:0).
   
   Note: When the virtual disk is created, it creates a second virtual SCSI controller.
   
   
4. Select the second virtual SCSI controller.
5. Click Change Type.
6. Select the controller type and click OK.
7. Click OK to finish editing the properties of the virtual machine.
8. Power on the virtual machine.
9. After the operating system boots, log in to the virtual machine. The operating system automatically detects the new SCSI controller and adds the appropriate drivers.
10. Power down the virtual machine.
11. Remove the added virtual disk. The controller is removed automatically.
12. Change the first virtual controller to the desired setting.

13. Power on the virtual machine.

[WindowsCSD]

Hello,

My solution, performed on vCenter 5.5 standalone. vCenter is a VM.

Disk system should not be changed to Paravirtual. (moast probably SCSI 0:0)

VC downtime (maintenance): 30 minutes to 1 hour.

1. Connect ton the ESXs host and shut down the VC VM.

2. Edit VM settings and remove (but not delete from disk) all disks which had to be converted to Paravitual.

3. Add the disks back and configure SCSI as 1:0, 1:1 and so on , for each disk.

4. Change the SCSI controller 1 to Vmware Paravirtual

5. Now click OK for applying the new settings.

6. RDP (connect) to VC VM, and open Disk Management.

7. Bring Online all disks.

8. Reboot the VC VM.

Hope this solution works for you as well.

[JonRoenick]

Caused a bsod on Windows Server 2012 R2 running VC 6.0 update 2

Tried this - Changing the hard disk mode of a virtual machine fails with the error: Access to resource settings o... - but didn't help the situation, bsod again. Might be a 2012 thing?