I can’t help but smile upon reflection of the last couple days at work. I guess I’m still in the midst of it, but I believe the information below will be relevant to others.

For a little background, I’m building Windows Server 2008 / Exchange 2007 clusters hosted on vSphere with NetApp storage. Thus, I have installed SnapDrive 6.1 onto my Windows VMs. Also important to note, is that vSphere installed the LSI SAS SCSI Controller for my 2008 Servers….

Using SnapDrive to create the iSCSI LUNs was very easy, it was great! This was my first time using it and I was delighted to see that it created the disks, formatted them, created cluster resources, etc, etc. However, the quorum had to reside on a Fibre Channel LUN and SnapDrive, seeing that it can recognize that it is installed into a VM, can create LUNs of Fibre storage because it can use the FC “Initiators” on the ESX server. I was told the quorum had to be on Fibre Channel storage in order to be supported by NetApp, VMware, and Microsoft. Granted, I’m not sure the verbage is right but hopefully you get my point.

Anyway, when creating the FC LUNs using SnapDrive, I received the following message when it attempted to create the LUN:

Failed to create disk in virtual machine, Failed to Map virtual disk: There are no available SCSI controllers..

After a bit of troubleshooting, we decided to contact NetApp. We ran through a couple basics, they were going to review the logs, etc. When speaking with support today, I was told the following “bug” update (366239) had just been released.

http://now.netapp.com/NOW/cgi-bin/bol?Type=Detail&Display=366239

366239
Error “There are no available SCSI controllers” is thrown up by SnapDrive running in win2k8 VM.

Bug Severity: 3 – Serious inconvenience
Bug Status: Fixed
SnapDrive running in Win2k8 VM (configured with virtual LSI SAS controller) and being hosted by ESX Server 4.0 throws up an error “Failed to create disk in virtual machine, Failed to Map virtual disk: There are no available SCSI controllers” during LUN create, connect or mount operations.

Configure VM with LSI parallel controller and do not use LSI SAS controller.

Of course my VMs were using LSI SAS controllers! Anyway, I can confirm that this bug is indeed a serious inconvenience as you typically cannot simply change your controllers “on the fly” so to speak. Doing so tends to render Windows unbootable; but you can step through a process to convert your SCSI controller from LSI SAS to LSI Parallel (and vice versa). I used the steps found here: http://blog.tpv.dk/?p=53 though I may post what I did as well for my own memory….

After converting my SCSI controllers to LSI Parallel, SnapDrive was able to map a Fibre Channel RDM to my Exchange virtual servers and I could proceed with my Exchange 2007 cluster build.