KVM Reviews

KVM runs virtualized guests with its own kernel, which is very important to me.

I mainly use it for customer projects, as KVM allows running virtualized environments for free in a very efficient way. Furthermore, it is an open source solution so modifying the code is possible. One might think that this is never necessary for most projects; however, when a specific customer requested an enhancement of the functionality, I was able to provide that. The customer was very impressed that KVM is such a professional solution although it is free.

Over the years, many customers were happy that they were able to choose between VMware, Xen and another alternative - KVM.

Setting KVM up and running it with dozens of parameters can be annoying. However, there is a control interface called Virsh (and also a GUI called virt-manager) which allows running KVM guests with a simple config file.

I have been using KVM since 2010, so for fives years in total.

So far, no issues.

When running I/O intensive tasks, or having a very high amount of network packages which need to reach the guest(s). However, all issues were under control after tuning the config of the KVM guests.

No issues yet.

There is no customer service, only the community. It is a free product, based on open source software. However, one can use RHEV (the enterprise virtualization product from Red Hat), then you will be able to contact the Red Hat support.

I used Xen in the past and switched because the customers requested a solution which allows running a guest with its own Kernel. This is also possible with Xen, but not a common use case, though.

The initial setup, when done manually, is complex because you need to be an experienced Linux user or admin, especially as the networking part can be challenging.

I always deploy it on my own.

It is free! Use it and if you need enterprise support, make sure to use RHEV, the virtualization product from Red Hat.

No, because in the open source world, there are not many hypervisors which have the same feature set as KVM.

Make sure to gain a lot of knowledge about virtualization and the way KVM works. Then implement it with libvirt and virt-manager because this makes running KVM guests a lot easier.

We are using KVM across our company for virtualization.

In our setup, we do not have any dashboards or orchestration, and it is hard to manage. We have 25 gig network cards, but the software driver we have only supported 10 gigs.

I have used KVM within the last 12 months.

KVM is stable.

We have used Baremetal.

There are different types of implementations and the current implementation we had, we did not spend enough time to optimize it for a highly demanding production environment. We were not running the most sensitive applications in that environment. Where we needed performance we run Baremetal. In the near future, we are going into cloud-native Kubernetes space as well.

We had some problems with the licensing.

We have evaluated Kubernetes.

We have had a lot of problems with the solution but it is not the fault of KVM. It was our fault for not doing a full suite deployment.

I rate KVM a seven out of ten.

The main use case is, of course, to run virtual machines. The specific use case is to run virtual network functions (VNFs) and the performance is very good on KVM.

A big strength with KVM is that it is an open-source component. It gets improvements from Intel, for example, and the other semiconductors. It can be sized-down to a very small package. It can be used in embedded systems as well, so it has a very good performance and it is suitable from embedded IT to big servers and supercomputers.

This solution integrates nicely with other soft-open-software components.

I would like to see a separation, so you could have KVM running in a few cores, and then you could have a real-time operating system running another core, so there is a hybrid environment with real time operating systems and Linux.

The stability is very good. It has not crashed once since we have been using it. 

I think nine out of the ten supercomputers in the world use Linux KVM, so I think that attests to the fact that it is a scalable product. It scales really well.

Technical support is not top-notch.

I think this solution is in need of an easier installation process.

It is cheaper than other competitors like VMware or Hyper-V.

We compared KVM vs VMware and did a proof-of-concept, but we decided that KVM was best suited for our needs when it came to device drivers, etc. We also considered Oracle and RedHat.

KVM is very difficult to manage and run on daily operations. It's also too dependent on other solutions and has no backend customization.

I've been using KVM for five to six years.

KVM's stability is fine, assuming it's running on decent hardware.

KVM is scalable, but it requires a certain amount of technical knowledge to understand how it can scale to other locations.

The initial setup was very easy.

I implemented KVM myself.

KVM is free.

I would give KVM a rating of eight out of ten.

We integrate KVM as part of our product. I'm the CTO of our company. 

The solution is very cost-effective. VMware is exorbitantly priced and compared with other products KVM is much cheaper especially in the public cloud scenario.

Their support for snapshot and revert could be improved. I'd also like to see the product achieve high availability across clusters and to have more support for Apache CloudStack.

I've been using this solution for over a year. 

We haven't had any issues with stability. 

Scalability is fine, no problems at all. 

We have worked with certain support vendors and they're fine. In particular, we work with one of the Red Hat partners and we're quite happy.

The complexity or otherwise of the initial setup depends on the situation but generally it's not too difficult. We offer our customers maintenance support which generally involves update patching.

KVM offers both an open source and licensed version. 

Before deployment, it's worth checking whether the solution fits your use case and how it would be used across various large deployments. Test it before implementing. 

I rate the solution seven out of 10. 

My primary use case for KVM is running multiple VMs and containers on the one node.

I find the density of the product most valuable. It is because of kernel same page merging technology (KSM) that is integrated into Linux kernel. That high density makes KVM one of the important players of the virtualization market.

In the future release of KVM, I would like to have improved support for Windows guests.

The stability of this solution is less than other products in the same category. But, it is OK. 

The scalability of the product is really high because of architecture. Since KVM is part of a Linux kernel, it gets a lot of the benefits of its location. It has a nice strategy of memory virtualization, which is also part of the kernel. Kernel location makes possible schemes of a vhost that boosts device performance.

We currently have 300 users of KVM, with about two people as support staff. We do plan to increase usage in the future. So, we will be scaling up in the future.

The KVM technical support is really bad. It has a number of empty channels for support. We have tried emails, as well. But, if you are not part of the community, they will not answer your request. 

We previously used VMware. 

The initial setup was simple because KVM is used in Linux, so to get it out of the box is a simple task. But, the deployment is not an easy task. It takes a lot of installation suites. You could use a lot of additional products or improvements, like Red Hat virtualization that makes deployment of virtual machines simple. But, out of the box deployment is not that good.

This solution came with the Linux license.

Our primary use for this product is server virtualization.

There is a lot of value with an open source solution because you have some freedom of changing how the system behaves and looks because it's open source. You can modify to your requirements which you cannot really do with VMware.

The management of the whole system, could be improved. VMware is better on the management tools, for example, Red Hat is when it comes to the KVM.

In addition, we would like to have a software lifecycle solution included in this solution. We can handle the software needed for KVM, but also the software that we provide. A lifecycle component would be very beneficial.

It is a verty stable solution.

We have over 1000 users using the solution currently. 

If I were to rate the technical support on a scale of one to five, I would give it a four. We received good support and there is an on-site presence, as well. 

We previously used VMware but switched to KVM because it is an open ecosystem and we see there is a benefit in open source solutions.

It's very straightforward because there are a lot of examples of how to use it. 

It is cheaper than other solutions out there on the market.

We also evaluated Red Hat, SUSE, Canonical(Ubuntu), and other Linux providers.