When a web hosting company offers VPS, there are two types, OpenVZ and KVM.
Sometimes it's not obvious which type of VPS is being offered. The term "Cloud" will sometimes be used when KVM is being used.
OpenVZ
OpenVZ (Open Virtuozzo) is an operating-system-level virtualization technology for Linux. It allows a physical server to run multiple isolated operating system instances, called containers, virtual private servers (VPSs), or virtual environments (VEs).
Pros:
Easier for the web host to support, it requires less knowledge.
Cons:
On extremely large web sites it's not as easy to dedicate additional resources, but extremely large web site would be using a dedicated server, so this is a non-issue.
KVM
Kernel-based Virtual Machine (KVM) is a virtualization module in the Linux kernel that allows the kernel to function as a hypervisor. It was merged into the mainline Linux kernel in version 2.6.20, which was released on February 5, 2007.[1] KVM requires a processor with hardware virtualization extensions, such as Intel VT or AMD-V.[2] KVM has also been ported to other operating systems such as FreeBSD[3] and illumos[4] in the form of loadable kernel modules.
Pros:
On extremely large web sites it's not as easy to dedicate additional resources, but extremely large web site would be using a dedicated server, so this is a non-issue.
Cons:
Many web hosts simply don't have the knowledge to properly support it. The end results is a forum which has many problems.
Sometimes it's not obvious which type of VPS is being offered. The term "Cloud" will sometimes be used when KVM is being used.
OpenVZ
OpenVZ (Open Virtuozzo) is an operating-system-level virtualization technology for Linux. It allows a physical server to run multiple isolated operating system instances, called containers, virtual private servers (VPSs), or virtual environments (VEs).
Pros:
Easier for the web host to support, it requires less knowledge.
Cons:
On extremely large web sites it's not as easy to dedicate additional resources, but extremely large web site would be using a dedicated server, so this is a non-issue.
KVM
Kernel-based Virtual Machine (KVM) is a virtualization module in the Linux kernel that allows the kernel to function as a hypervisor. It was merged into the mainline Linux kernel in version 2.6.20, which was released on February 5, 2007.[1] KVM requires a processor with hardware virtualization extensions, such as Intel VT or AMD-V.[2] KVM has also been ported to other operating systems such as FreeBSD[3] and illumos[4] in the form of loadable kernel modules.
Pros:
On extremely large web sites it's not as easy to dedicate additional resources, but extremely large web site would be using a dedicated server, so this is a non-issue.
Cons:
Many web hosts simply don't have the knowledge to properly support it. The end results is a forum which has many problems.
