I currently have an ESX cluster consisting of 2 hosts that I am trying to add a third to. The third host has SAN storage and VMs currently running on it. The existing cluster also has SAN storage and running VMs. I have had the storage admin present the LUN from the third host to the first two in the cluster. In Storage Adapters the LUN appears on all three hosts but despite multiple refreshes it does not appear to the first two in Storage, an Add Storage operation would wipe out the LUN so that's out. My Disk.MaxLUN setting is sufficiently high on all servers that they shouldn't have issues with the number of LUNs. If anybody could help I'd appreciate it.
I don't think the setting in the Disk.MaxLUN has anything to do with it since when you scan your HBA for new devices you are able to see it right??? So I think what is happening is that the LUNs are presented to the other two servers with a different LUN ID and that is when you try to add it to the other two servers they see it as new unformatted storage. DO NOT FORMAT it or you will lose all of the date that you already have for the third server. What kind of SAN do you have? Are you zonning? Sometimes it is best to present the storage to all of the ESX boxes at the same time or else this is what happens. One thing you can start thinking about is enableling the LVM.Volume Resignaturing and enabeling LVM.DisallowSnapshotLun in the Advanced Settings under LVM. I had a similar issue but it's been a long time and I don't quite remember how I did it so PLEASE READ as much as you can and then make your determination if that is what you want to do. I think that will get you moving in the right direction.
You may have hit it, now I just need to know how to fix it. The first to hosts in the cluster see the LUN as vmhba0:0:0:8 and the third recognises it as vmhba0:0:0:1, how to proceed from here?