Several months ago, I posted a blog on adding a new disk to an existing cluster. Another question we get asked a lot is “How do I replace a disk?”
In this blog, I’ll walkthrough the process of replacing a 1GB disk with a 2GB disk. This process is similar to how you could go about doing a SAN migration where you are replacing all of your shared disks with storage from a new SAN.
The preferred way of getting a larger cluster disk is to use the built in capability of most SANs to dynamically expand a LUN then use an OS utility like DiskPart or Disk Manager to extend the size of the disk. If that’s not feasible or you simply want to replace a LUN with a larger one or as I mentioned, as part of a SAN migration, this process works well.
The first thing we need to do is present your new disk to the cluster. The nuts and bolts of how to do that are outside the scope of this post so just ask your SAN administrator for a new LUN and present it to all nodes of the cluster. Since by default in Server 2008, we leave new LUNs offline, there’s no risk in presenting a new LUN to all nodes at the same time. In the below figure is what Disk Manager would look like after my new disk had been presented.