Many organizations often face a grave danger: their hardware, that was very modern ten or twenty years ago, faces every problem associated with being a legacy system. If you think of that as three or four issues, you are going to be shocked.
Unplanned downtime, system outages, security vulnerabilities, reduced compatibility with modern platforms, deficient DR – they all attack the infrastructure that was once the picture of advancement.
And that’s not all. Costly maintenance, immense power consumption that affects sustainability, rarity of spare parts and technical replacement personnel, declining customer base, loss of revenue, etc. are also included in the list.
A full migration requires too much money, a lot of time, and several migration specialists working full time. The modernization attempt still turns out to be unsuccessful at times due to various mistakes and complications. Business continuity is ruined as a result.
In such cases, two routes turn out to be the most effective options: emulation and virtualization. Which do you choose? Before looking at a comparison, let us understand what they mean.
What is Emulation?
Emulation is the process of recreating the software environment, that was on the original hardware, on another. The user cannot identify that the hardware has been changed because the operating systems and applications function exactly as before.
This is especially useful if an enterprise uses legacy servers and workstations. The outdated hardware is on the brink of total failure, so they are replaced with modern systems. However, the old software cannot be changed as they handle mission-critical tasks.
Plus, as we said, total software migration takes time, effort, and money and can hamper business continuity. Hence, the software ecosystem is replicated, and the original applications and data are run on the new hardware to maintain operations.
The mechanism is simple: an interpreter or binary translator in the emulator software receives instructions from the guest system. The emulator, in turn, translates the instructions to a form the host would understand. The effect is that the guest machine thinks that it is operating on the original hardware, when it is actually the host.
As we stated, emulation is carried out by an interpreter or binary translator, but the process is different for them. An interpreter transforms one instruction at a time, which makes it more accurate but inefficient.
A binary translator, on the other hand, transforms blocks of instructions at every cycle, which can be fast but complex. A hybrid approach is coming up nowadays, where instructions are initially interpreted. They are translated from the next instance, based on which blocks of instructions are used more.
Emulation in the cloud is also possible. Cloud emulation further allows you to get rid of hardware and completely utilize modern computing. You can use AWS, Azure, Google Cloud, OCI, IBM Cloud, and more for the process.
What is Virtualization?
Virtualization is the method of running several virtual entities in a single physical one. It can be used on servers, storage, networks, etc. and is great for optimizing the use of hardware without sprawl.
Here, a software called the hypervisor is used for the virtualization process. It divides the physical hardware into multiple virtual machines (VM) by abstracting the physical components like the processor, storage, RAM, and network interfaces. These then form the respective virtual versions, assigned to each VM.
These VMs are completely isolated from each other and assume the identities of an independent machine. Each VM can run a different operating system and separate applications.
There are two types of virtualizations: Type 1 or bare-metal and Type 2 or hosted. There is also OS-level virtualization, known as containerization. Containers are lightweight and portable.
Virtualization can be of various types, like server, storage, networks, CPU, data center, desktop, data, and application. We also get cloud virtualization, which can be Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS), or Software-as-a-Service (SaaS).
Virtualization is a great option to host legacy systems on modern hardware and protect them with modern cybersecurity, disaster recovery, sustainability, and more. Management of resources also becomes easier.
A Comparison Between Emulation vs. Virtualization
Comparing emulation and virtualization seems simple on the surface, especially when it comes to legacy systems. One runs software on it meant for different hardware; the other creates a virtual set of machines on a single physical one. However, there is more.
Here is a comparison table for emulation vs. virtualization:
| Basis of Comparison | Emulation | Virtualization |
| Enforcing Tool | Uses an interpreter or binary translator | Uses a hypervisor |
| Instruction Path | Translates instruction from guest to host | Runs instructions directly on physical CPU |
| Compatibility | Runs software from hardware with different architecture than host | Same CPU architecture between host and guest machines |
| Speed | Slower than original | Near-native |
| Overhead | High | Low |
| Number of Guests Created | One | Multiple |
| Best for | Legacy systems (including on cloud), retro games, cross-platforms | Modern OSes, servers, cloud, legacy systems (if wanted) |
| Use | Quick modernization, testing | Scalability, security, disaster recovery |
| Example | QEMU, Stromasys | VMware, Hyper‑V, KVM |
Which Option Should You Choose: Emulation or Virtualization?
It is difficult to make a hard-and-fast rule when it comes to selecting between emulation and virtualization for extending the life of legacy systems. Each has their pros and cons, and neither can be ignored.
The best solution is to go for the hybrid approach that combines both emulation and virtualization. This takes a virtual machine and emulates an aging system within it for seamless operation of legacy workloads.
As a result, you get the optimization of your legacy infrastructure with emulation within the hardware efficiency of virtualization. The disadvantages of both are quashed using this simple technique.
Concluding Remarks
For a company already handling the responsibility of maintaining its operations and serving its customers, a legacy system is the last thing they want to worry about, even if it is on the minds of the IT team.
Yet, if they do not take care of their vintage hardware, chances are a system failure or network outage will make them realize the immediate need for migration. There is a short-cut approach though: Stromasys.
You can use its Charon solutions to emulate SPARC, VAX, AlphaServer, PA-RISC, and PDP-11 hardware for continuation of your operations. You can even utilize legacy-to-cloud migration for multiple benefits.
