Server virtualization – Silverton Consulting

Is cloud computing/storage decentralizing IT, again?

Posted on January 26, 2011 by Ray in Cloud services, Server virtualization, Strategic Inflection Points, Strategy, System effectiveness, Systems

IBM Card Sorter by Pargon (cc) (From Flickr)

Since IT began, over the course of years, computing services have run through massive phases of decentralization out to departments followed by consolidation back to the data center. In the early years of computing, from the 50s to the 60s, the only real distributed solution to mainframe or big iron data processing was sophisticated card sorters.

Consolidation-decentralization Wars

But back in the 70s the consolidation-decentralization wars were driven by the availability of mini-computers competing with mainframes for applications and users. During the 80s, the PC emerged to become the dominant decentralizer taking applications away from mainframes and big servers and in the 90s it was small, off-the-shelf linux servers and continuing use of high-powered PCs that took applications out from data center control.

In those days it seemed that most computing decentralization was driven by the ease of developing applications for these upstarts and the relative low-cost of the new platforms.

Server virtualization, the final solution

Since 2000, another force has come to solve the consolidation quandry – server virtualization. With server virtualization such as from VMware, Citrix and others, IT has once again driven massive consolidation outlying departmental computing services to bring them all, once again, under one roof, centralizing IT control. Virtualization provided an optimum answer to the one issue that decentralization could never seem to address – utilization efficiency. With most departmental servers being used at 5-10% utilization, virtualzation offered demonstrable cost savings when consolidated onto data center hardware.

Cloud computing/storage mutiny

But with the insurrection that is cloud computing and cloud storage once again, departments can easily acquire storage and computing resources on demand and utilization is no longer an issue because it’s a “pay only for what you use” solution. And they don’t even need to develop their own applications because SaaS providers can supply most of their application needs using cloud computing and cloud storage resources alone.

Virtualization was a great solution to the poor utilization of systems and storage resources. But with the pooling available with cloud computing and storage, utilization effectiveness occurs outside the bounds of the todays data center. As such, with cloud services utilization effectiveness in $/MIP or $/GB can be approximately equivalent to any highly virtualized data center infrastructure (perhaps even better). Thus, cloud services can provide these very same utilization enhancements at reduced costs out to any departmental user without the need for centralized data center services.

Other decentralization issues that cloud solves

Traditionally, the other problems with departmental computing services were lack of security and the unmanageability distributed service both of which held back some decentralization efforts but these are partially being addressed with cloud infrastructure today. Insecurity continues to plague cloud computing but some cloud storage gateways (see Cirtas Surfaces and other cloud storage gateway posts) are beginning to use encryption and other cryptographic techniques to address these issues. How this is solved for cloud computing is another question (see Securing the cloud – Part B).

Cloud computing and storage can be just as diffuse and difficult to manage as a proliferation of PCs or small departmental linux servers. However, such unmanage-ability is a very different issue, one intrinsic to decentralization and much harder to address. Although it’s fairly easy to get a bill for any cloud services, it’s unclear whether IT will be able to see all of them to manage it. Also, nothing seems able to stop some department from signing up for SalesForce.com or even to use Amazon EC2 to support an application they need. The only remedy, as far as I can see to this problem, is adherence to strict corporate policy and practice. So unmanageability remains an ongoing issue for decentralized computing for some time to come.

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Nonetheless, it seems as if decentralization via the cloud is back, at least until the next wave of consolidation hits. My guess for the next driver of consolidation is to make application development much easier and quicker to accomplish for centralized data center infrastructure – application frameworks anyone?

Comments?

Enterprise data storage defined and why 3PAR?

Posted on August 25, 2010 by Ray in Block Storage, Data growth, File Storage, Storage availability, Storage Features, Storage performance, Storage reliability

Recent press reports about a bidding war for 3PAR bring into focus the expanding need for enterprise class data storage subsystems. What exactly is enterprise storage?

Defining enterprise storage is frought with problems but I will take a shot. Enterprise class data storage has:

Enhanced reliability, high availability and serviceability – meaning it hardly ever fails, it keeps operating (on redundant components) when it does fail, and repairing the storage when the rare failure occurs can be accomplished without disrupting ongoing storage services
Extreme data integrity – goes beyond just RAID storage, meaning that these systems lose data very infrequently, provide the latest data written to a location when read and will tell you when data cannot be accessed.
Automated I/O performance – meaning sophisticated caching algorithms that try to keep ahead of sequential I/O streams, buffer actively read data, and buffer write data in non-volatile cache before destaging to disk or other media.
Multiple types of storage – meaning the system supports SATA, SAS and/or FC disk drives and SSDs or Flash storage
PBs of storage – meaning behind one enterprise class storage (sub-)system one can support over 1PB of storage
Sophisticated functionality – meaning the system supports multiple forms of offsite replication, thin provisioning, storage tiering, point-in-time copies, data cloning, administration GUIs/CLIs, etc.
Compatibility with all enterprise O/Ss – meaning the storage has been tested and is on hardware compatibility lists for every major operating system in use by the enterprise today.

As for storage protocol, it seems best to leave this off the list. I wanted to just add block storage, but enterprises today probably have as much if not more external file storage (CIFS or NFS) as they have block storage (FC or iSCSI). And the proportion in file systems seems to be growing (see IDC report referenced below).

In addition, while I don’t like the non-determinism of iSCSI or file access protocols, this doesn’t seem to stop such storage from putting up pretty impressive performance numbers (see our performance dispatches). Anything that can crack 100K I/O or file operations per second probably deserves to call themselves enterprise storage as long as they meet the other requirements. So, maybe I should add high-performance storage to the list above.

Why the sudden interest in enterprise storage?

Enterprise storage has been around arguably since the 2nd half of last century (for mainframe systems) but lately has become even more interesting as applications deploy to the cloud and server virtualization (from VMware, Microsoft Hyper-V and others) takes over the data center.

Cloud storage and cloud computing services are lowering the entry points for storage and processing, enabling application deployments which were heretofore unaffordable. These new cloud applications consume storage at increasing rates and don’t seem to be slowing down any time soon. Arguably, some cloud storage is not enterprise storage but as service levels go up for these applications, providers must ultimately turn to enterprise storage.

In addition, server virtualization transforms the enterprise data center from a single application per server to easily 5 or more applications per physical server. This trend is raising server utilization, driving more I/O, and requiring higher capacity. Such “multi-application” storage almost always requires high availability, reliability and performance to work well, generating even more demand for enterprise data storage systems.

Despite all the demand, world wide external storage revenues dropped 12% last year according to IDC. Now the economy had a lot to do with this decline but another factor reducing external storage revenue is the ongoing drop in the price of storage on a $/GB basis. To this point, that same IDC report stated that external storage capacity increased 33% last year.

Why Dell & HP wants 3PAR storage?

Margins on enterprise storage are good, some would say very good. While raw disk storage can be had at under $0.50/GB, enterprise class storage is often 10 or more times that price. Now that has to cover redundant hardware, software/firmware engineering and other characteristics, but this still leaves pretty good margins.

In my mind, Dell would see enterprise storage as a natural extension of their current enterprise server business. They already sell and support these customers, including enterprise class storage just adds another product to the mix. Developing enterprise storage from scratch is probably a 4-7 year journey with the right people, buying 3PAR puts them in the market today with a competitive product.

HP is already in the enterprise storage market today, with their XP and EVA storage subsystems. However, having their own 3PAR enterprise class storage may get them better margins than their current XP storage OEMed from HDS. But I think Chuck Hollis’s post on HP’s counter bid for 3PAR may have revealed another side to this discussion – sometime M&A is as much about constraining your competition as it is about adding new capabilities to a company.

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What do you think?

Why virtualize now?

Posted on August 25, 2009 by Ray in Systems

HP servers at School of Electrical Engineering, University of Belgrade — HP servers by lilit

I suppose it’s obvious to most analyst why server virtualization is such a hot topic these days. Most IT shops purchase servers today that are way overpowered and can easily execute multiple applications. Today’s overpowered servers are wasted running single applications and would easily run multiple applications if only an operating system could run them together without interference.

Enter virtualization, with virtualization hypervisors can run multiple applications concurrently and sometimes simultaneously on the same hardware server without compromising application execution integrity. Multiple virtual machine applications execute on a single server under a hypervisor that isolates the applications from one another. Thus, they all execute together on the same hardware without impacting each other.

But why doesn’t the O/S do this?

Most computer purists would say why not just run the multiple applications under the same operating system. But operating systems that run servers nowadays weren’t designed to run multiple applications together and as such, also weren’t designed to isolate them properly.

Virtualization hypervisors have had a clean slate to execute and isolate multiple application. Thus, virtualization is taking over the data center floor. As new servers come in, old servers are retired and the applications that used to run on them are consolidated on fewer and fewer physical servers.

Why now?

Current hardware trends dictate that each new generation of server has more processing power and oftentimes, more processing elements than previous generations. Today’s applications are getting more sophisticated but even with added sophistication, they do not come close to taking advantage of all the processing power now available. Hence, virtualization wins.

What seems to be happening nowadays is that while data centers started out consolidating tier 3 applications through virtualization, now they are starting to consolidate tier 2 applications and tier 1 apps are not far down this path. But, tier 2 and 1 applications require more dedicated services, more processing power, more deterministic execution times and thus, require more sophisticated virtualization hypervisors.

As such, VMware and others are responding by providing more hypervisor sophistication, e.g., more ways to dedicate and split up processing, networking and storage available to the physical server for virtual machine or application dedicated use. Thus preparing themselves for a point in the not to distant future when tier 1 applications run with all the comforts of a dedicated server environment but actually execute with other VMs in a single physical server.

VMware vSphere

We can see the start of this trend with the latest offering from VMware, vSphere. This product now supports more processing hardware, more networking options and stronger storage support. vSphere also can dedicate more processing elements to virtual machines. Such new features make it easier to support tier 2 today and tier 1 applications sometime in future.