KVM Architecture
In the KVM architecture the virtual machine is implemented as regular Linux process, schedule by the
standard Linux scheduler. In fact each virtual CPU appears as a regular Linux process. This allows KVM to
benefit from all the features of the Linux kernel.
Device emulation is handle by a modified version of QEMU that provides an emulated BIOS, PCI bus, USB bus and a standard set of devices such as IDE and SCSI disk controllers, network cards, etc.
Multi-domain SSL
Multi domain certificates make it possible to secure up to 100 domains on the same server with a single certificate. You can mix all your different second level domains (i.e. domain.com, domain.net, and otherdomain.com).
A multi domain certificate is best for organizations that have multiple unique domains hosted on a single server. This saves time and money while providing a high level of trust and security. Compare the cost of purchasing many individual certificates to purchasing a single multi-domain certificate (which can consolidate as many as 100 domain names)
The Xen Hypervisor Platform
The Xen Hypervisor Platform is comprised of two components – the Xen hypervisor which is responsible for the core hypervisor activities such as CPU, memory virtualization, power management and scheduling of virtual machines.
The Xen hypervisor loads a special, privileged virtual machine called Domain0 or dom0. This virtual machine has direct access to hardware and provides device drivers and I/O management for virtual machines.
Each virtual machine, known as an unprivileged domain or domU, contains a modified Linux kernel that instead of communicating directly with hardware interfaces with Xen hypervisor.
CPU and memory access are handled directly by the Xen hypervisor but I/O is directed to domain 0. The Linux kernel includes “front end” devices for network and block I/O. Requests for I/O are passed to the “back end” process in domain 0 which manages the I/O.
Releasing IP Addresses in WHM/Cpanel
Apache
By default Apache listens to every interface coming into the machine by listening to 0.0.0.0:80/443. Normally you could edit the httpd.conf file directly in order to change the listen line, however that may cause problems with Cpanel’s automation.
To acheive this log into Webhost Manager and find Service Configuration followed by Apache Configuration. Then click on Reserved IPs Editor.
Here you will need to check the boxes of the IP addresses you do NOT wish for Apache to use. Once you save your selections, a new configuration file will be configured to listen on all the other IPs that were not checked. This will allow other services such as alternate web browsers to listen on those IP addresses without conflicting with Apache.
Webhost Manager
Navigate to IP Functions, followed by Show/Edit Reserved IPs. Here you should check the same IPs that were selected in the Apache Reserve list above.
Once this is done WHM/Cpanel will avoid using those IP address when setting up new accounts and services.
Cygwin
Cygwin is a set of powerful tools to assist developers in migrating applications from UNIX/Linux to the Microsoft Windows platform. Cygwin delivers the open source standard Red Hat GNU gcc compiler and gdb debugger on Windows. In addition, it provides for a standard UNIX/Linux development environment on Windows including APIs and command shells. The Cygwin.dll library, included with Cygwin, delivers the interesting subset of UNIX SVR4, BSD, and POSIX APIs to enable quick ports of UNIX/Linux applications to the Windows platform.
Red Hat Cygwin is supported on Windows 2000, XP, 2003 Server, Vista, 2008 Server, 7, and 2008 Server R2. Cygwin is a 32 bit platform that will operate on both 32 and 64 bit Windows installations.
The Red Hat Cygwin official installation utility : ftp://ftp.ges.redhat.com/private/releng/cygwin-1.8/rhsetup.exe
