Server Virtualization Software Forum

Rony_Sklar
IT Central Station
Jul 10 2020
How do these two types of virtualization differ? What are use cases for each?
José RiosTeam my answer, a virtual server works like a traditional server, however you can create the servers you need in minutes, whether in a physical environment, on a local network and in the cloud. In virtual servers, users can have information and work with their physical PC. A virtual desktop is a technology also derived from server virtualization, therefore it can be on virtual servers or in the cloud. Virtual desktops, the user works in a separate session from a virtual server. In this you have saved your own profile and all your programs, files and applications that you need. To access this virtual desktop, you just need to have on hand a device such as: PC, laptop.
Bhupesh AroraServer Virtualization means virtualizing physical servers in your data center, which is usually being done by type 1 hypervisors like vmware vsphere, KVM or Xen based virtualization techniques. It is used majorly to better utilize hardware resources, reduce physical space required, reduce power & cooling costs, most importantly to maintain availability of services even if there is any resource failure.  Desktop Virtualization on the other hand is to virtualize the desktops of end users in the data centers. Actually there are few various ways & use cases. When you virtualize the desktops in a data centers, you call it VDI technology. There are many companies with their employees work on thin client like devices those are virtualized using VDI technology (like Eg. Citrix Xen Desktops). But now people wants to work across various devices (like Desktops, laptops, smart phones, tablets, etc), so VDI has improved multi fold over the years.  Another way to virtualize desktops is via products like Virtualbox, Vagrant or vmware Horizon) where many developers are taking advantage of working on multiple types of environments, OS platforms. So, in a nutshell, when you are thinking about optimizing servers in your dc, you talk about server virtualization. & when you are thinking about optimizing the way employees work on various devices, you talk about VDI technology.
Rozaino Sarbini
Senior Manager at NCS Group
Jun 18 2020
What are the Pros and Cons of OVM vs Esxi?
Rony_Sklar
IT Central Station
May 27 2020
Can you explain what an IOMMU is? How does it improve VM performance?
DEEPEN DHULLAIn virtualization, guest operating systems can use hardware that is not specifically made for virtualization. Higher performance hardware such as graphics cards use DMA to access memory directly; in a virtual environment all memory addresses are re-mapped by the virtual machine software, which causes DMA devices to fail. The IOMMU handles this re-mapping, allowing the native device drivers to be used in a guest operating system. Read more technical : https://en.wikipedia.org/wiki/Input%E2%80%93output_memory_management_unit and alos https://wiki.archlinux.org/index.php/PCI_passthrough_via_OVMF#Setting_up_IOMMU https://www.linux-kvm.org/page/How_to_assign_devices_with_VT-d_in_KVM In plain language it help in using hardware resource in VM , as good as it had direct hardware full access., thus you use original driver and code in VM too and able to get best performance.
Allan TrambouzeDEEPEN DHULLA did explain well IOMMU. IOMMU have to be activated at the bios level. It exist on Intel and AMD platform. it is used a lot inside virtualization platform like VMware vsphere. It provide a direct access to the underlayer hardware for a VM. https://docs.vmware.com/en/VMware-vSphere/6.5/com.vmware.vsphere.networking.doc/GUID-DD13D453-98B9-4D26-85EA-A738293AEE00.html?hWord=N4IghgNiBcIJIHkCySCqIC+Q
Syed Zaffar
Cloud Admin at CtrlS Datacenters
May 05 2020
I work as a cloud admin for a mid-sized tech services company.  We are currently researching server virtualization tools. What are the biggest differences between VMware vSphere, Citrix XenServer, Hyper-V, and Proxmox in terms of features and costs? Are there other solutions you would recommend? Thanks! I appreciate your help. 
Rohit ZanwarWhat kind of workload you are running? There are multiple solutions available. If you are looking for redundancy & scalability, I would recommend to check out Nutanix.
Rathin Vaidya1. VMware is the more popular server virtualization software and has been the pioneer in server virtualization. 2. Citrix Xenserver or Now Citrix Hypervisor is another alternative. However, a major problem that I have faced with Xenserver is that very few Backup software vendors provide full support for XenServer. Due to that, we cannot take full backup of VM (Virtual Machines ) which we can do with VMware. 3. Hyper -V is surely a contender, but from a reliability point of view, you have to find out the reference cases wherein a large number of VMs have been deployed in a production environment. 4. No experience on ProxMox. So if budget is not a constraint – and should not be from the reliability point of view---go for VMware. You may consider Citrix Hypervisor & Acronis Backup software as a combination if that works our to be cheaper. Thanks
Krishna RandadathI would like to know whether your infrastructure is converged or hyperconverged? if it is hyperconverged, I would recommend Nutanix, if it is converged VMware is your best bet. If you are an EMC shop then VXrail is your best bet. So it depends on what you want. And if you are using the Cloud, you can use AWS services for the virtual host if you are hosting it on the cloud.
Richie Murray
Technical Support Engineer with 1-10 employees
Which hypervisor provides the best network performance at 10gb or higher? What do you all think?
Hassan IsmailOn a basic, structural level, virtual networks aren't that different from physical networks. So In virtualization, virtual switches are used to establish a connection between the virtual network and the physical network. Once the vSwitch has bridged the connection between the virtual network and the physical network, the virtual machines residing on the host server can begin transferring data to, and receiving data from, all of the network-capable devices connected to the physical network. That is to say, the virtual machines are no longer limited to communicating solely across the virtual network. What I want to say the network performance depend on many factors rather than hypervisor itself with my long experience in virtualization after working on VMware, OVM, KVM, Hyper-V, and Nutanix AHV, we can get the best performance for all of these hypervisors if we are using the proper NIC card, physical server, and physical switches. From my point of view, Nutanix can provide the best performance due to the data locality which can offer more than 10 Gb for the hosted virtual machines. But again you can gain the best performance from VMware if you have the best design.
Patrick RingelbergI have worked only with VMware Hypervisor and have seen that for most customers a 2 x 10Gbit connection it works fine when using in combination with the distributed virtual switch with network profile on it. (VMware QOS) in the DVS.
Fábio RabeloUsing Intel network cards 520 and 540, I have not tested any 550 yet. Proxmox gets the best performance, but not by much, XEN and VMware get really close, I do not think it can be the "deciding" factor. With Broadcom network cards the result changes a lot. In this case, Proxmox gets WAY better performance compared to XEN and VMware but is a little slower than Intel. I will not provide numbers because my tests are very informal and relaxed, just copy a big file, or open a bunch of queries in an SQL server.