In this guest blog post on the Tintri blog, vExpert Bill Hill explores the trade-offs between single and multi-hypervisor external cloud providers.
As virtualization takes a strong hold in the datacenter, virtual machines (VMs) no longer run in a “virtualized” environment: Rather, the term has changed to “cloud.” If you have a hypervisor in your environment, it is your “internal cloud” or “private cloud.” If you use infrastructure from a hosting company, it is your “external cloud.” Running machines in both internal and external clouds is a “hybrid cloud.”
A new market has popped up to support external and hybrid cloud environments. Suddenly, the same companies (and service providers) that provide hypervisors want to enable enterprise IT to leverage external resources and infrastructure to run the very same internal-cloud VMs in their environments. This market is forking into two distinct groups: single-hypervisor cloud providers and multihypervisor cloud providers.
Single-cloud products, such as VMware vCloud, focus on supporting a single hypervisor. If you run the VMware hypervisor internally, do not bother trying to migrate VMs to Amazon EC2.
Multihypervisor cloud products, such as OpenStack, focus on customer flexibility by providing support for multiple hypervisors. Theoretically, you could move a VMware-based VM and a KVM-based VM to the same hosting provider.
So, the question becomes: In the event you want to utilize an external cloud provider, why would you choose one over the other? There is definitely no right or wrong answer to this question.
First off, why use an external cloud provider (regardless of single vs. multihypervisor support)?
This question is the topic of much debate. Security concerns aside, external cloud products provide some interesting functionality. The following factors can help determine the best choice:
The biggest point to make is that applications really need to be built to scale. They do not need to be cloud-aware, but need some level of WAN functionality or be completely autonomous. If load balancers, reverse proxies, caching, replication, etc. are not available, you may end up doing more harm than good. Cloud is an architectural decision and should not be taken lightly.
Vendor lock-in vs. selection of the most convenient provider
Anytime a vendor has a very compelling product, it is likely you will use it more and more. All of the cool whiz-bang features become ingrained into the infrastructure. Suddenly, you are locked into the vendor’s product. Is that a bad thing? Some would say yes, others would say no. However, one would expect a cloud product provided by or based on a vendor’s product to have deep support for all of the functions you depend on. Plus, the vendor may push out functionality that leverages your investment: More bang for your buck for buying into their product lines.
On the other hand, with a multihypervisor external cloud provider, you are not locked into a single product line. Rather, you get the best of many worlds. For example, if you run ESXi for server virtualization and Hyper-V for desktop virtualization, an OpenStack solution provider may be what you are looking for.
Adaptive vs. homogenous functionality
Products from a vendor are updated, upgraded, add functionality and get overhauls all the time. This is the natural progression of production software. Single-hypervisor external-cloud products can keep up with the development of the underlying hypervisor and adapt to the growing environment. Multihypervisor external cloud products are less likely to stay up-to-date, as they are concerned with maintaining compatibility across all supported hypervisors. One would expect that in the long term, some of the new functionality would be supported, after rigorous testing and implementations.
What is the true value in selecting a multihypervisor cloud provider?
Multicloud providers really have a market in:
The fight for relevance and market domination is strong right now. VMware’s vCloud product is highly compelling for VMware customers. However, the cost to play ball is significant and other non-vCloud options exist that are appealing, especially if you do not need all of the integrations and functionality vCloud provides. OpenStack, CloudStack, and Eucalyptus have up-and-coming alternatives that may give vCloud a run for its money.
Cloud computing is not all sunshine and rainbows. The model has to fit your needs. If you decide cloud computing in your future, think carefully about security implications, cloud provider locations, connectivity, integrations into existing infrastructure, and the right provider. External cloud computing has huge benefits; just make sure you get onboard when you are ready and with a partner that can help you along the way — with single or multiple hypervisor support.
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