Mike Stone (@), CIO & Principal Architect
I recently read about a feature of NetApp called “FlexClone”, which promises instant virtual-to-physical (v2p) cloning of VMDK files, which reside on a NetApp NFS DataStore for VMware. This idea was intriguing, since one of the questions our customers often ask us is “What do I do when Oracle asks me to reproduce a problem on physical?” My initial response is to point out that Oracle is first obliged to research the issue and make a determination that it’s not something they’ve seen before. Sometimes this involves requesting a duty manager to explain how things work to the misinformed support tech. The next step, obviously, is to involve VMware’s Oracle Support team, which is included in your contract with VMware. They will interface directly with Oracle and attempt to achieve resolution of your issue.
Nevertheless, in the remote chance that I actually have to do it… What are my options for spinning up a physical copy of a database virtual machine when it’s data volumes are VMDKs?
There are a number of products that offer to do that for you, and some of them can do hot clones (PlateSpin, for instance). We’ve discussed them in other articles, but the drawback is that they can take a lot of time – especially for large databases. Since the risk of having to do it is extremely low, it’s also possible to cobble together manual methods that involve cloning the entire datastore or making use of in-guest solutions involving RMAN or even Data Guard. But all of these options can be pretty tedious, and that’s why the NetApp offering really caught my eye. That, in turn, led to a few hours of research on NetApp products and licensing… Why can’t we make these things simple, folks?
Here’s what I found during my research:
The NetApp software for managing snapshots and clones is called SnapManager. It works peachy with their products and plain old files or even entire NFS volumes. It also has plugins (and “components”) that work with other products, making use of NetApp hardware; including Microsoft SQL Server, Oracle and VMware. The plugin for Oracle is called, cleverly, SnapManager for Oracle (SMO) while VMware functionality comes with SnapManager for Virtual Infrastructure (SMVI). The latter includes an agent, called the Virtual Storage Console (VSC) that installs in vSphere Virtual Center and provides NetApp tools with controls inside the virtual space – presumably to coordinate access to VMDK storage (among other things). Finally, FlexClone is an optional component of the NetApp Suite that works with SnapManager to provide the elusive “instantaneous v2p” – touted by a colleague, Vaughn Stewart in his VCE-101 blog post.
Still with me? Anyway, SnapManager can produce consistent hot copies of Oracle databases using the SMO plugin. Likewise, it can do something similar for Microsoft with the appropriate plugin. So the $64K question is – does that also work with FlexClone giving me an a) instantaneous, b) consistent and c) physical clone or snapshot of my database volume(s) that reside on a VMDK? What about just making a snapshot to another virtual file for backups or cloning? The product literature makes it sound feasible. But, maybe not surprisingly, even NetApp can’t answer the question with a straight yes or no.
So, I’m putting it out to the larger audience – has anybody done this? Do I have all the right pieces identified? And, if it is possible, what do I need to buy? Share your thoughts by adding a comment below.