KVM Reviews

We are using KVM on-premises with Ubuntu 20.04 for the primary purpose of reducing operating expenses (OpEx) and to make maintenance and security easier for us. Of note, with this kind of virtualization technology, you can very easily create backups and restore data in case of disaster.

The services that we have running on our virtualized KVM environment are currently being used by everyone at the company, numbering in the range of thousands of end-users.

We also make use of Proxmox VE and, less often, VMware.

The most helpful aspect of KVM is the fact that the interface is so minimal. It includes just what you need to set up the VMs and manage them, and it's very simple to do so. You don't need to go with the typical black-screen command-line interface; instead, you just have a small graphical interface with which you can create VMs, edit them, upgrade calculations, and perform other administration tasks. And, because the interface is so lightweight, it has very low memory usage.

KVM, as a native virtualization solution, is a complete and fully adequate system for small businesses that need to reduce costs, and also to make maintenance easier. 

One problem I have is that it's not very scalable when it comes to resizing the VM disk dimensions. For example, if you have initially set a virtual drive to 10 GB and you want to upgrade it to 15 GB, it's not that easy. For this kind of task, you have to get behind the command-line to set it, and this process isn't easy for a newcomer. However, if you have planned your virtualization project well and you know exactly how much RAM and storage space you will need for each different VM, you can simply set it and forget it, because everything you set is permanent.

Another improvement I would like to see is better functionality when it comes to making snapshots automatically while the VM is still running. For example, when a VM is running and you want to back it up, occasionally the VM backup that you obtain is not usable. Thus, I would propose that in the next edition of KVM there should be better "hot" backup features (as opposed to "cold" backups which are performed when the VM is powered down). 

I have been using KVM for about six years.

KVM is extremely stable, to the point where I would give it 5/5 stars for stability.

In terms of expanding the dimensions of your virtual disks, KVM is not easy to scale. Let's say you have a 10 GB disk, and you want to scale it up to 15 GB, the process requires that you enter a basic console and use the command-line interface to set the new size. It's not always an easy process for beginners. On the other hand, it is easy enough to scale other resources such as the CPU and RAM.

However, in general, when it comes to supporting a large number of users, it is scalable enough for us as we have thousands of users in the whole company using the services that are being virtualized with KVM.

Additionally, it's not hard to scale when talking about labor and maintenance. For example, I'm the only one administrating the infrastructure, by setting up and managing the VMs (e.g. adding VMs, editing configurations, etc.), for all these thousands of users in all different positions of the company.

I provide support for the system myself and I have not yet needed additional support, mainly because I only use it for basic operations.

KVM is a perfect alternative to commercial solutions in the market such as VMware, especially when it comes to stability. In my experience, KVM is more stable than VMware.

I performed the initial setup and I did not need to contact support. Instead, I provided the support I needed by myself, in order to become comfortable with the basic operation of KVM. Compared to Proxmox, the setup is very similar, although admittedly Proxmox offers a more user-friendly interface to manage VMs.

In all, the setup took about two hours. If the internet connection is good, I install the operating system, then set up the hypervisor and perform the updates before installing the VMs. Two hours is about enough for this entire procedure. 

There is no cost involved in the use of KVM, as it is open source.

On the whole, I would certainly recommend KVM to new users. Going further, I would give the following advice: although it's true that deep administration can be a bit difficult for newcomers who are not used to Linux, if you just follow the tutorial on KVM deployment and plan your deployment properly, you will be able to set up a stable virtualization system with ease. That's one of the perks of KVM — it's natively very stable once it has been set up correctly.

I would rate KVM an eight out of ten.

I have used KVM in production, testing, and development environments. Additionally, I have configured it in both normal and high-availability environments. 

The platform's most valuable features are stability and ease of management.

They could provide a more comfortable and easier-to-manage interface for the product, whether text-based or graphical. It can be challenging to manage without the support of additional tools.

I have been working with KVM for around three years.

The product is stable. I rate the stability a ten. 

The product is scalable. I rate the scalability a seven out of ten. 

I have resolved any issues I encountered through the KVM documentation and user forums without needing to ask direct questions to the community.

KVM is superior to VirtualBox regarding stability, scalability, and high availability capabilities. While VirtualBox is also a good tool, KVM, especially with Proxmox, offers better deployment options and more flexibility in licensing compared to other virtualization solutions like Hyper-V or VMware.

The setup is complicated. Depending on the environment, it typically takes two days to one week to complete.

I rate the process a three.

Typically, deploying KVM requires only a single individual. However, this person must possess specialized skills in virtualization, Linux, and potentially programming environments such as Bash.

I use KVM for free through Proxmox, which offers a free license alternative. If I needed direct technical assistance, I could purchase a Proxmox subscription at an affordable price. 

I recommend KVM to others and rate it a ten. 

We use KVM for virtualization. 

The tool's most valuable feature is backup. The product makes it easy to manage virtual machines. Other tools require third-party applications like VMware and vSphere. However, KVM doesn't require these applications. 

I have been using the product for six to seven years. 

The data is in high availability. If my servers undergo maintenance, we switch to another virtual machine host. We delete the maintenance activity, restoring it to the original state, ensuring the users have no downtime.

We can add multiple hosts. Currently, we have three physical hosts with 30-40 virtual machines running. If there is a requirement change, we can easily add more rules or expand the cluster without any issues.

We rely on community support since we use the tool's open-source version. Tech support is available for subscription-based versions. 

I have worked with VMware before KVM. You need a subscription and license to work with VMware. VMware has features like vMotion and storage vMotion. KVM has the same features as well. The main difference between the two is in licensing costs. 

KVM is easy to install and manage. After installing the hypervisor, you can manage changes easily from the web console. You can modify policies, adjust settings like high availability, and access other advanced configurations by logging in. You can complete the deployment in one host in 10-15 minutes. 

KVM is an open-source solution. 

I rate the product a nine out of ten. 

We use KVM virtualization on which Red Hat works very actively. We run Windows servers from it and some of our other machines as well. We also use it as a container in the way others may use Docker.

We can use the solution the same way we use Red Hat, even though we don't use Red Hat itself. 

It offers a high-availability environment. We like the way everything is distributed. If one node dies, another resource is automatically enabled.

It offers good virtualization.

The solution, generally, is very familiar to VMware. The difference it is free to use. It has all of the main features you would find on VMware.

It works 24/7 without fail. 

The setup is very simple. 

It is stable.

The solution can scale.

We have found the solution to have good forums for troubleshooting. 

If it would work a little faster, that would be ideal. It's run on a 10GB network, so it is relatively slow.

Some things are pretty basic, and they could be more robust with more detail.

I've been using the solution for ten years or more. 

It is a completely stable solution. While there may be a few bugs, in general, we didn't face any special issues. 

The solution is scalable. You can have as many servers as you want to run as a deployment. I'd rate the scalability nine out of ten. We use CEPH storage that is extremely scalable and can go up to petabytes, although we don't have a use case for that sizing. 

We likely do not have plans to increase usage. Our basic needs are covered.

I've never used technical support. There are forums, however, that are available if people need assistance. Typically, if something comes up, you aren't the first person dealing with it. 

We have used VMware and Microsoft Hyper V, among others, and then changed to KVM. I was not happy with Hyper V at all as we didn't want to use any Microsoft domain, and Hyper V needed us to use it. KVM allows us to avoid Microsoft. 

The initial setup process is pretty simple and straightforward. Even in high availability mode, the setup is simple. 

If you have, for example, three servers and all of them can run the restore machines, and one dies, and everything moves to the others, for that step, you do need some sort of storage.

The deployment takes two or three days, at least if you need to start from scratch.

If you are doing the implementation in combination with setting up separate networks and everything, you need to program the hardware and so on, and that takes a little bit. 

I'd rate the ease of setup an eight out of ten. Sometimes it doesn't work as you expect at the outset. We just need one person to handle the setup as we are a small company.

The solution is free to use and open-source. You may have to pay for support, however. There is an enterprise option that can be accessed as well. 

I am an end-user.

I'm not sure which version number of the solution we're using. 

I'd warn users that if they do not have experience with systems, then it may not be suitable. You need a bit of knowledge. Most companies use system integrators, and it is hard to sell free software. You can sell your services, yet not the solution. It's easier to sell VMware. I wouldn't necessarily recommend it to customers who don't have technical skills.

I'd rate the solution nine out of ten.

The use cases for KVM depend on the customer's needs, and I deliver different customer services. For example, if a customer wants a virtual machine for a certain purpose, I give them a finished solution.

The most valuable feature of KVM is its stability.

The solution’s user interface could be improved and made more user-friendly.

I have been using KVM for five years.

I rate KVM a nine out of ten for stability.

I provide other solutions like VMware virtual desktop and ESXi server.

The solution’s initial setup is straightforward.

We deployed the solution through an in-house team in 10 to 15 minutes.

I use the free version of KVM, and I'm not sure if there is a paid version.

I would recommend KVM to other users.

Overall, I rate KVM a nine out of ten.

The solution is used as an additional solution for small and medium enterprises in many configurations from just a stand-alone server with some VM's to a few nodes'  clustered virtualization service with hundreds of VMs. Currently, In KVM I have one server for ten to fifteen machines and a three-node cluster with all the features and capabilities.

KVM is my second alternative to virtualization, it complements other things I cannot do with my main virtualization service.

Documentation and problem-solving troubleshooting are the most valuable features. Performance (when fine-tuned and with "special" HW) is awesome, equal to or more than other enterprise closed-source solutions.

Performance-wise it's very similar to other hypervisors, and it is the hypervisor core for other virtualization solutions (just like Proxmox).

The networking with wireless devices needs improvement. If I want to mount KVM on a laptop, it is very difficult to work with wireless devices. Which in contrast, is very easy and transparent in other devices.

I have been using KVM for six years. 

The solution is highly stable. I rate the stability a ten out of ten. 

KVM is a very scalable solution. I rate the scalability a nine out of ten. 

The technical support team is good but I use the support from the open source community. I rate the technical support a nine out of ten. 

Positive

I used to use another hypervisor, but licensing just bored me, so I found KVM. It is powerful and open source and it has a very big support community.

The initial setup is difficult and requires some effort. But since the solution is so powerful, it is worth the effort. I've been working with KVM mostly on-premises but I've deployed it also on private and public clouds. I rate the initial setup's easiness a five out of ten. 

I've always worked on KVM by myself and with support of the KVM community.

I previously evaluated VMware, almost all variants, and Oracle VM Enterprise.

KVM is not easy to configure and has some minor issues. I rate the overall solution a nine out of ten. 

Apart from being difficult at its installation and initial setup, the rest is wonderful!

We moved from VMware to KVM and now use KVM for server virtualization.

Since we use a Docker, the virtualization works fine whether it's KVM or VMware. We don't use this feature much, our developers use Docker to create a container.

The solution overall is just okay. We moved since we are sharing the commercial term from publisher to subscription.

I have no comment. I just use it, and it's okay. However, the scalability part should be better.

I started using the solution some years ago.

The stability is just okay. We haven't experienced any major glitches or downtimes.

I'd rate scalability maybe seven or eight out of ten. It could be better.

We use community support and search for help on the internet.

Neutral

We used VMware before switching to KVM.

For us, the initial setup is okay and simple. We can live with it.

It's just a small setup, which helps save the operation cost.

For basic functions, it should be okay. It helps save operational costs.

I'd rate the solution seven out of ten.

The most valuable feature of the solution is that KVM is much more flexible than Oracle VM. Multithreading in KVM is also a very good feature. Oracle VM supports only serial ports, so executions happen one after the other, while KVM supports parallel ports, allowing you to do multiple tasks at the same time, which also makes it a more flexible choice.

Sometimes, my company has some issues with the storage part, which is mostly not the fault of KVM but a problem with the storage. In general, I don't have any downsides or negative points related to the tool.

In KVM, snapshots and cloning are areas where there could be a little more sophistication, like VMware.

I have been using KVM for five years. My company recommends KVM to potential customers.

Stability-wise, I rate the solution an eight out of ten.

It is an easily scalable solution.

My company communicates with Oracle Linux's technical support, and sometimes the support is good, while sometimes it may be a bit less.

My company has experience with Oracle Linux VM and Oracle VM apart from KVM. KVM and Oracle Linux VM are more stable and flexible compared to other products in the market. My company does not recommend products from KVM's competitors since we have an Oracle-centric environment, and most of the time, we get VMs with Oracle licenses only. Oracle VM will not do anything to improve the product since it can be described as an end-of-life product.

I rate the overall product an eight out of ten.