Kernel-based Virtual Machine (KVM) vs. Proxmox VE vs. XenServer

KVM is the best solution in the case you need to test and turn up any virtual environment with limited vCPU/RAM resources. The obvious area of its use is a network environment when we want to avoid being tied to one type of hardware/vendor and being able to swap from one instance to another with no downtimes. The use of a vSwitch (that supports VLAN tagging) is a significant bonus for network engineers that some other hypervisors do not provide.

Incentivized

We used Proxmox to implement private cloud services, for clusters
of a small number of servers, from 3 to 11 with and without high
availability. Allways with ZFS file systems, and we used to install the
root pool in SSDs mirrored and use other pools with RAID 10 in groups of
four, for the virtual machines and containers, for the backups and snapshots, we used magnetic disks with RAID 10, in groups of four. Do
not use an even number of servers because does not facilitates the
implementation of High Availability, because the corosync service must
have an odd number of servers to detect a failed server for the quorum
system. We used a variety of servers, from clone PCs with AMD Ryzen with 6 cores and 12 threads with 64 GB of RAM no ECC, to high end servers with 64 cores and 128 threads per cpu and 2 cpus per server, with AMD EPYC Rome or Milan, 2 terabytes of RAM ECC.

Incentivized

It can be really helpful & useful if we are using Citrix Hypervisor with other provisioning tools. Here are some specific scenarios where Citrix Hypervisor (formerly Citrix XenServer) is well-suited: Server Consolidation, Virtual Desktops, Disaster Recovery, Development & Testing Environments. On the other hand, there are some scenarios where Citrix Hypervisor may be less appropriate: Small-scale Deployments, Highly Heterogeneous Environments, and Limited Virtualization Requirements.

Incentivized

• KVM is really good at providing fast and reliable virtualization for Linux guests
• Since KVM is a kernel module, every VM is a Linux process which can be managed by Linux system tools
• KVM integrates very well with the management framework libvirt, which is why KVM can be integrated in automation tools as well

Incentivized

• BackUp System, provides extensive propiertes and verifications. An exclusive server for BackUp Administration (PBS)
• Hardware Customization. You can select several properties to adapt the hardware to your needs
• Easy administration. You will be able to manage the server with easily accessible tools such as the web console and usage statistics.
• Certificates Administration.

• Citrix hypervisor does price very well for small organizations. It is free.
• Since this product is open source it does not have any type of vendor lockdown issues.
• Allows live migration of VM's so you can keep systems up and running when changes are needed to the hardware in the background.
• The GUI management tools are quite easy to learn.
• Has Snapshot capability which is a great way to protect against malware as well as do risk-free upgrades.

Incentivized

• KVM itself doesn't ship with a management interface
• KVM itself is a bit complicated to handle
• KVM needs Qemu to virtualize Windows guests

Incentivized

• The web UI does not work as well on mobile devices. It is useable, but a mobile optimised / responsive UI would be nice to have. There is a mobile app, so that may alleviate this issue, but I have not yet tried it.
• Support in the community forums could be better. There are paid support plans, but new users trying out the software will not have access to this. Answers to questions can sometimes be terse, and I can imagine this may put some people off.
• The wiki is a bit hit and miss with certain topics. I've often seen outdated or missing information, and the whole thing looks like it could do with some polish. I'd love to see it opened up for the community to add to.

Incentivized

• Adding or presenting additional storage to the host can often be a task that is far more involved than competitive products.
• The product can require reboots more frequently than competitors due to the DOM kernel getting "hung up".
• Sometimes when a virtual machine is deleted it still leaves behind orphaned vdisks.
• Recovering from the loss of a host can sometimes cause virtual machines to require lengthy command prompt scripting to fix so they can be powered back on from another host.

Incentivized

Proxmox VE provides the most capable, yet stable virtualization platform in the market today. Licensing options are also competitive and cost-effective for support, and support is extremely fast and knowledgable of getting issues resolved as quickly and soundly as possible.

Incentivized

With the knowledge and usage of solutions from VMware and Microsoft offering more compelling cloud integrated options it makes it more compelling in many environments which I consult. XenServer is a good product and fits the bill in many smaller environments but as clients look to the cloud or a hybrid cloud it can in some cases make it a bit more difficult.

Incentivized

It does the job and stays out of the way. The specifics of usability relies on the implementation, but with things like Icarus and libvirt, things are standardizing nicely.

Incentivized

The interface is easy to use for most of it, but still lacks screens for some configurations. Also, a few of the screens are not as intuitive as they could be. This is specially true with disk and network configuration, where some graphic/visual representations of the configurations would be very useful

Incentivized

XenServer is a good product in its use and probably free if you have the right Citrix licenses already. However, it does require specific knowledge to manage, which makes it harder to manage if you don't have that knowledge in house.

Incentivized

Proxmox VE's ha-cluster functionality is very much improved, though does have a not-very-often occurrence of failure. In a 2-node cluster of Proxmox VE, HA can fail causing an instance that is supposed to migrate between the two nodes stop and fail until manually recovered through the command-line tools provided. Other than this, the HA clustering capability of Proxmox VE has proven to be reliable in 3 or more clustered environments with much less chance of these failures to occur.

Incentivized

It's been a little problematic in the past at larger VDI deployments requiring a bit more care and feeding than other vendors. But the latest releases (6.5.x) have brought about huge improvements in the stability and availability.

Incentivized

Proxmox VE's interfacing is always fast to load, both the Web interface and the command-line tool interfaces. Reporting is practically real time almost all the time, and you can see everything in mere seconds, easily able to identify if something is wrong or it everything is in tip-top shape as always desired

Incentivized

When running like a top XenServer is a fantastic hypervisor. There is relatively low overhead on the Dom0 so workloads get the most of the resources.

Incentivized

They are fast, understanding, very intelligent, know their product very well, fast, responsive, and concise. Need I say more?

Incentivized

The staff I've worked with are very knowledgeable or able to get a very well articulated and capable support team member on the phone or helping them if necessary and they always want to ensure the best experience possible for you on the platform. The ability for the support team to reach out to hardware vendors for assistance is a nice plus too.

Incentivized

Part of a training for certification to become a trainer for Citrix included an in-person training with a Master CCI. The XenServer training at this time was pretty simplified due to the product primarily being installed however you did have to work with it and mildly configure the system.

Incentivized

Haven't given it a real go with any online training however there are some options out there. I have taught a course following Citrix material for XenDesktop which leverages XenServer and it is pre-built so not the best for XenServer specifically for installation but configuration is mildly touched on

Incentivized

It worked, was easy and super fast to deploy, and provided everything we needed in a matter of minutes

Incentivized

Ensure you review the HCL (hardware compatibility list) and reach out to the hardware vendors to ensure they support the platform and in case they have documentation that can be followed for the implementation. Also ensure the prerequisites are completed prior to implementation so that as few unexpected delays occur as you can control.

Incentivized

It is a very reliable solution that can be used for x86 architecture virtualization with low overhead. It is a free and open source software. Easy to use withOpenStack.

Incentivized

Proxmox VE is cheaper than VMware, especially upscaling an HA architecture. Compared with other free or less expensive solutions, Proxmox VE is high compatible with more types of hardware solutions and more VM types. From my point of view, Proxmox VE has no competitor at the same price level, it offers the most complete and production-ready HA solution.

Incentivized

Feature for feature they are neck and neck. I have used Hyper-V 2012 and 2016, VMware ESXi and XenServer evenly. XenServer is a fast install, good documentation, with enterprise features out the box that compare or exceed what VMWare offered with a higher cost of entry.

Incentivized

Proxmox VE provides everything you need to quickly add new storage mediums, network and local, as well as networking interfaces, such as using Linux standard bridges and now Open-vSwitch bridges which can be even more scalable than before. Proxmox VE 4.0 dropped support for OpenVZ in favor of the more well supported and native LXC and made an upgrade path to it very simple.

Incentivized

The servers latest versions have made massive improvements to scalability. But from past experience there have been issues when running workloads for extended periods of time without reboot on the hosts. I would need to run similar workloads on the 6.5 release which has changed much of the bottlenecks or issues so I'd imagine its far more capable now, Perhaps able to stand near the best in the market.

Incentivized

• Fast provisioning of new servers.
• Huge drop of the cost of servers compared to bare metal.
• Easy upgrades of resources, sometimes now even requiring a server restart.

Incentivized

• Due to the open source nature of Proxmox, we have no licensing costs while training our employees
• We've migrated 100% of our clients to Proxmox and have found improved uptime, and flexibility.
• In the 10 years of using Proxmox, we've yet to lose any data or not be notified of backup issues.

Incentivized

• Xenserver is easy to learn. We paid for support only for installation and deployment in the first three years, and now our team has the knowledge to solve most problems.
• Low CAPEX if you have a team that uses open source software day by day.
• But paid support is necessary to solve critical problems. The open source community is not enough. Actually, we have difficulty solving some bugs without paying for support.
• Medium OPEX if you have a team that uses open source software day by day.

Incentivized