Why does a single SAN volume present differently to different hosts?

Question

Hello,

I have an issue that we've never seen before. I attached a volume on a SAN to 3 virtual hosts that we have. It is the D: drive on all hosts, and shows up with the same volume name and shows the same used and free space.

The weird part is that each host seems to see the volume differently. For example, we created a virtual hard drive for a virtual machine on Host 2. This .vdx file is not seen on Host 1 or Host 3. Trying to migrate the VM fails.

As a test, I created a "Test" folder on D: on Host 3. This folder is not visible from either of the other hosts. That tells me that the issue is at the host OS / SAN level and not anything to do with our virtual environment.

I looked at the drive and folder Security, but nothing jumps out as obvious. What am I missing?

Thanks.

Zachary Hamilton

Answer 1

Hi,

I’m not too familiar with SAN but I found a link Mounting Single San Drive on Multiple Hosts which might help.

As Chopper3 said, each file system assumes that they have full access to their disks. So when attaching a volume on a SAN to 3 virtual hosts, there are 3 volumes. One volume for one host.

If you want to make them present same in different hosts, as Chopper3 suggested, you could try cluster-aware filesystems.

Please note: Information posted in the given link is hosted by a third party. Microsoft does not guarantee the accuracy and effectiveness of information.

Answer 2

What I had to do was follow the directions on this page...

https://learn.microsoft.com/en-us/windows-server/failover-clustering/failover-cluster-csvs

...in the section "Add a disk to CSV on a failover cluster", and then below it in the section "Add a disk in Available Storage to CSV".