When I first met a VMware technical rep several years ago, and heard him present and extol the benefits of virtualization (more specifically VMware ESX Server), I never forgot the most important words I ever heard: “Virtualization is NOT an excuse for executing ‘Stupid IT Tricks’.”
Hmmm… I pondered those words for a while. Back then, I was dealing with issues around the procurement of physical server resources, and uniform provisioning of those resources in the environment, while maintaining order and manageability in the infrastructure. Risk management, and more specifically backup and recovery, and disaster recovery controls and measures were paramount, and considered the priority of the day. The features of ESX I saw were compelling.
Virtualization, as presented with all of the features offered in the ESX platform, brought a change in my mindset for many areas, including backup and recovery via snapshots, redundancy and high availability via vMotion and HA, and heterogenous systems manageability (removing vendor lock-in at the hardware level). But, his words stuck with me: No “Stupid IT Tricks” with virtualization.
Fast forward many years. I was there, last week, sitting in a locally promoted presentation on Microsoft’s Hyper-V platform (their new hypervisor) for a Microsoft User Group. The presenter seemed knowledgeable, and at times, extremely enthusiastic about virtualization and its benefits. This is probably why he felt compelled to start at the beginning, and talk about virtualization as a whole, and not just in the context of Microsoft. He did a decent job… in the beginning.
His enthusiasm turned dangerous, when, to a crowd of about 30 individuals (many who seemed nascent to the area of virtualization hands-on) he began shouting about how “snapshots” of Virtual Servers totally replaced backup and recovery as we know it! (Personally, I was stunned.) Literally, he stated “look at this, with snapshots, backup and recovery of files is old school. I can just take a snapshot of a server, running anything…SQL Server, Exchange, and other services, while they are running, and if there is a problem, I can revert back…like this. Whola!” His demo of snapshots and reverting of a plain vanilla install of Windows Server 2003 in a VM worked, of course. It was plain vanilla.
What’s the problem, you might say? He did not mention the need to quiesce those services, like SQL or Exchange, while the snapshot was taken in order to maintain data integrity, and prevent corruption. And for such block type data, having a true data backup via specific agents serves a different function then just a snapshot, which is best served as a disaster recovery solution. How many of those individuals left that presentation thinking “wow, I can get rid of ArcServe and its agents…”, or worse, “no more tape drives or near line storage for backup versions”.
He continued the presentation, and made another grave error in judgement, in my opinion. He said “clustering as you know it, and as you need it, is gone!”. He described, very loosely, the clustering of the Hyper-V servers (similar to an ESX farm), and how you could “quick migrate” a VM from one server to the other. And, he added, if a VM goes down, its “data files are copied to another server in the cluster, and automatically started”. Now, I will admit, I do not know much about Hyper-V, so hopefully, his rough description of this process results in a similar process as that of VMware HA. Nonetheless, he went on to say that “Microsoft Clustering, SQL clusters and Exchange clusters are a thing of the past”. Wow.
Again, clusters at the application services level serve a different purpose than clusters at the utility computing level, as in ESX and Hyper-V. I know I have always err’d on the side of having critical application services clustered, whether via VM, physically or both, because other than VMotion, the amount of time necessary to restart that service proved an unacceptable RTO (recovery time objective) for the business.
He continued on, and again, his enthusiasm was great. He loves virtualization. But, the issue I have, is “does he understand what he should and should not do with it and the features a virtual platform provides?”
Virtualization is a great, and probably the best, strategy for x86 infrastructures of the 21st century. However, the key is this: “Virtualization is NOT an excuse for ‘Stupid IT Tricks’.”
What do you think? Let us know and comment below.
- clikdude
Tags: Hyper-V, Snapshots, Virtualization, VMotion
