1.What is virtualization?
Ans. Virtualization is an abstraction layer that decouples physical hardware from operating system to deliver greater IT resource utilization and flexibility.
2. What is the Difference between Full Virtualization and Para Virtualization?
Ans. Full virtualization & Para virtualization both comes under the Hardware virtualization. Some of the difference between them are listed below:
Full Virtualization: In full virtualization guest vm’s (Virtual Machines) are not aware that they are in virtualized environment there-fore the guest os issues command to what it thinks as actual hardware but actually are just simulated devices created by the hosts.
Para Virtualization: In para virtualization the guest vm is aware that it is in a virtualized environment. If guest vm requires resources, it issues commands to host operating system instead of directly communicating with simulated hardware.
3.What is Hyper-visor?
Ans. Hypervisor is a software platform (more like a OS) which is directly installed on physical hardware, further which creates and manages virtual machines. The hypervisor is known as Host and the vms created are known as Guest vm’s .
4.What are the difference between Type 1 and Type 2 Hypervisor?
Ans. Type 1: When the Hypervisor is installed on bare metal / Physical hardware it is known as Type 1 Hypervisor. Examples are ESXi, OVM.
Type 2: When the Hypervisor is installed on top of a operating system it is known as Type 2 Hypervisor. Examples are Microsoft Virtual Server, VM Ware Server and workstation.
5. What are different hypervisors available in Linux?
Ans. Xen & KVM are two hypervisors available in Linux.
6. What is the difference between Xen & KVM?
Ans. For Xen hypervisor first we have to install Xen kernel and have to boot the machine with Xen kernel whereas KVM is kernel-based Virtualization, we don’t need any extra kernel for KVM. KVM is a module in Kernel. Xen hypervisor by default doesn’t support full virtualization whereas KVM supports Full virtualization.
7. What is Oracle VM Server?
Ans. A managed virtualization environment (Hypervisor) providing a lightweight, secure, server platform which runs virtual machines, also known as domains. Oracle VM Server is installed on a bare metal computer and contains the Oracle VM Agent to manage communication with Oracle VM Manager. It is available on two platform SPARC & X-86. On x86-based systems, Oracle VM Server is based upon an updated version of the underlying Xen hypervisor technology and includes Oracle VM Agent. It also includes a Linux kernel with support for a broad array of devices and file systems. The Linux kernel is run as dom0 to manage one or more domU virtual machines, each of which could be Linux, Oracle Solaris, or Microsoft Windows™.
8. What is a Farm in Citrix?
Ans. A Farm is a group of Citrix Servers which provides published applications to all users that can be managed as unit, enabling the administrator to configure features and settings for entire farm rather than configuring each server individually. All the server in the farm shares a single data-store. While designing server farms, keep in mind the goal of providing users with fastest possible application access while achieving the degree of centralized administration and network security.
9. What is a Zone in Citrix?
Ans. Zones are subset of Farm. It is a grouping of presentation server that shares common data collector. Zones are very helpful in controlling traffic.
10. What is ZDC (Zone Data Collector)?
Ans. Data collector stores all the dynamic information like session, load & published applications in the servers in their zones and communicates the zone information to other data collectors in other zones in the farm. Data collector is Citrix presentation server whose IMA service takes on the additional role of tracking all of the dynamic information of other presentation servers. This information is stored in memory and called as “Dynamic Store”.