Issue related to the VCB proxy needing access to LUNs used by ESX servers.

[sbranchfbfs]

To my understanding, a VCB proxy will need to see the LUNs that are used by the ESX servers to work properly. How can this be done if the LUN can only be accessed by a single host or cluster (the two or more ESX servers)? Wouldn't giving the VCB proxy (installed on a Windows Server 2003 machine) access to the LUN create the possibilty of data corruption?

Is there some way to give the VCB proxy read-only access to the LUN so that it cannot corrupt the data?

[jjohnston1127]

All of your questions and concerns are highlighted in the documentation for VCB but I will answer here for you.

One of the steps on the VCB proxy is to disable automounting of hard drives using diskpart. This will allow windows to see the disks, but not initialize them and attempt to write to them - essentially giving you read only access. It does not automatically initialize or assign drive letters to them.

[sbeaver]

Which is one of the most important first steps to take care off before you present the LUNS to VCB

Steve Beaver

VMware Communities User Moderator

*Virtualization is a journey, not a project.*

[bebman]

The VCB host will have to be zoned into the same group as your ESX servers. The key to preventing the data corruption is that you should not initialize the ESX "drives" in Windows on the VCB. The VCB uses code to connect to those "drives" in the same way ESX connects to LUNs.

You don't want to give the VCB read only access because during file level backups, it is creating a snapshot of the VMDK file and working from the snapshot. It has to have the ability to create that snapshot.

[sbranchfbfs]

I'll make sure to review the VCB documentation to educate myself on this process. It seems, though, that VCB should somehow automate this process. Oh well, I guess that is what updates are for. Thanks for your explanation on this.

[bebman]

Please mark the question as answered so points are awarded.

Thanks!

[eliot]

I was taking another look at VCB today after ignoring it since it first come out as I'm just not cool with presenting my vmfs luns to a Windows host. The potential for a mistake is too great IMO.

Furthermore, I wrongly assumed that once you install VCB onto windows, it somehow included some sort of protection to prevent silly mistakes, such as a someone formatting the VMFS datastore as windows - So as a test today, I did just that , expecting it to prevent me - but it didnt . I formatted and dropped a file onto what was a live (test) VMFS partition with a running VM on it.

It would be nice if there was some sort of protection in the framework to prevent this. Ideally I would like the volume not to appear in Disk Manager at-all.