Author Archives: Lance Castro

What is Citrix Xen?

            Citrix Xen is a popular hypervisor platform which is designed to help you create and manage virtualized server infrastructure. This hypervisor platform was designed by the Citrix Systems and has been built on the Xen hypervisor. The Citrix Xen provides monitoring services and server virtualization. It can be found in 64-bit hypervisor platform and good thing is that it can be successfully executed on all processors from the x86 series.

What Citrix Xen Can Do

            The platform offers good performance for client operating systems and baremetal virtualization performance for virtualized servers. It works by using the Xen hypervisor for virtualization of every server on which it is installed. That enables each server to host several virtual machines at the same time, providing fast and efficient performance. The Citrix Xen can also be used for combining several Xen-enabled servers into one strong resource pool, by using resource clustering and shared storage architectures. By doing so, Citrix Xen is extending the primary single-server notion of virtualization for enabling smooth virtualization of several servers as one resource pool. Its memory, CPU, storage and networking resources can be controlled dynamically for best performance, increased availability, and optimal use of data center resources.

            Very often skilled IT technicians and managers are using the Citrix Xen server for creating numerous clusters of resource pools. Then they manage those clusters and all their resources from a single spot for control. With Citrix Xen, several servers can become very helpful in protecting key application workloads. They can do that by using industry standard storage architectures. Great thing about Citrix Xen is that there is no downtime maintenance when you move virtual machines when they are running among machines within the cluster. The Citrix Xen cluster is extending the strongest abstraction – storage, virtualization across servers and networking. All of that is done so the users can realize the entire potential of the responsive, dynamic and very efficient data environment for Linux and Windows workloads.

            Through the component for virtual machine monitoring, Citrix Xen can manage the allocation and proper distribution of resources among many different virtual machines. It also administers their optimal performance and usage. Although it does sound a bit complicated, the IT managers know how to properly utilize Citrix Xen. This is an interesting subject that requires deeper insight for those that want to work with it. Get informed about Citrix Xen and put it in good use.

What is Citrix used for?

Citrix offers different services to businesses such as application, networking, virtualization or server. It helps businesses grow and expand on the market. There are three different branches of Citrix – Analytics, Networking and Workspace. In the past they offered remote access to some products of the Xen brand, but that stop when they made rebranding back in 2018. Products like XenApp, Xen Mobile and XenDesktop were renamed, but still provided the same services. The Virtual Desktops of Citrix now allow remote access to desktop, while Virtual Apps offer apps support. The hypervisor is the server virtualization platform that provides access to better desktop and app performance. Endpoint Management is also part of Citrix and that is the solution for mobility management.

What Does Citrix Mean and What Is Used For

            Citrix or Citrix Server is referring to the line of virtualization products – XenApp and Xen Desktop. The IT departments within companies can use these products for hosting centralized applications and desktops. They enable the users to access them from anywhere, regardless of the hardware they are currently using. XenApp and XenDesktop are ideal for cutting costs and increasing security, but without compromising the standardized environment. With Citrix Server, businesses need to upgrade the operating system or an application just once instead of presenting new versions to users. The XenApp virtualizes single applications, while XenDesktop usually virtualizes Windows desktop, but it can also be a Linux or Mac desktop.

            There are many advantages and benefits that come with using Citrix. One of the main advantages is that those organizations that have versatile environments can use the same applications. Users that have Linux, Windows or Mac desktops can have standard environments. Besides that, Citrix also offers quality mobile clients and their virtualized desktops support mobile users. An example of its use is on this site.  Specific industries like the medicine can significantly increase their security if they choose to store sensitive data on the server instead on devices that can be stolen such as laptops.

            These were some things in favor of using Citrix and the mentioned technology will continue to dominate in the upcoming years. Many companies are opting for its solutions because they are very helpful for specific industries. If you want to gain a more thorough knowledge into what Citrix is all about and what it is used for, it is advisable you get in touch with IT experts to give you best explanations about what it can do for you.

Does AWS use Xen Hypervisor?

AWS stands for Amazon Web Services and the question whether AWS uses Xen supervisor intrigues many people. Truth is that AWS is changing its tune because the new hypervisor plan is the way to go in the future. At the moment AWS uses a customized version of the popular Xen hypervisor. It takes advantage of the feature called paravirtualization because the paravirtualized guests are strongly relying on the Xen hypervisor for support of actions that usually require privileged access. The CPU has four different privilege modes – between 0-3 are called rings. Ring 0 is the one with highest privilege which is executed by the host OS. However, instead of executing in Ring 0 like most OS do, the guest OS is running into Ring 1 and the other applications in the lowest Ring 3. This virtualization of the resources points to clear separation between the hypervisor and the guest, which results in added security between the two.

What Goes On At the Moment?

            AWS has added brand new hypervisor, but truth is that customers will likely not notice huge impact when working in their cloud environment. The AWS now has KVM based hypervisor. It uses multi-hypervisor tactics by utilizing both Xen and KVM, depending on the specific requirements. AWS claim that they do not have any issues with Xen, they do continue to invest in it, but are seeking other options as well. All future platforms are expected to be used with best virtualization technology available. AWS plans to launch platforms which are built both on Xen and the KVM platform. The addition of KVM is interesting, but it is not very known whether this has any impact on the customers.

            AWS is juggling between Xen and other hypervisors for different instance types, and they are the only big services provider that still use Xen. The reason why they are using KVM is to cut some costs for development and support. After using Xen over a decade, AWS is challenged to transfer everything to KVM, but they are still not completely abandoning Xen. They are still working on many details that need to be perfected first. The AWS tools for cloud management must go towards new direction and evolve into multi-hypervisor. The new hypervisor will likely fit well with AWS hardware and will provide optimized security features and performance, but the final consumers will likely not notice any big difference.

What is the Xen Project?

Xen Project is open source baremetal hypervisor, integral part of the Linux kernel and available in Linux systems. It is one of the numerous projects that are handled by Linux Foundation.

Components of Xen Project

            Standard Xen-running environment is consisted of few different parts. There is a Domain 0, which is the way in which you call the operating system of the host. However, it is not a typical host OS because other virtual machines are not required to use it in order to gain access to the hardware of the host server. The so-called Domain 0 is only responsible for drivers` access, and if there is a need for some type of coordination then that will be properly handled by this Domain 0. Besides Domain 0, there are other virtual machines that are called Domain U.

            The Xen Project hypervisor can run many different operating systems on a single host or a machine. It is the one and only type 1 hypervisor that can be used as open source. Xen Project is typically used as a base for many different open source and commercial applications like desktop virtualization, server visualization, embedded Infrastructure as a Service, security applications and hardware appliances. A thing worth knowing is that Xen Project powers the biggest clouds you can find in production today.

            The main features of the Xen Project hypervisor are the following:

  • Paravirtualization is one key component through which the optimization is used so the paravirtualized guests run as virtual machines. That enables them to run faster in comparison to running wits some hardware extensions. Besides that, Xen Project hypervisor can run even on hardware that is not supportive of virtualization extensions.
  • Driver Isolation is another main feature. The hypervisor allows the driver of the main device to run inside the virtual machine. In case the driver is compromised or crashes, then the virtual machine that has the driver can be restarted and the driver will reboot without affecting or having any influence on other parts of the system.
  • The hypervisor has small interface and footprint, which is less than one megabyte in size. This is because it uses microkernel design and that leaves tiny memory footprint. That makes it more secure and more robust in comparison to other hypervisors.
  • Finally, operating system agnostic is another top feature. Many installations use Linux as their domain 0, but here many other operating systems can be used, such as OpenSolaris and NetBSD.