How to Enable Nested KVM

If you’ve arrived at this blog post I’d have to assume you’re familiar with what KVM is, but for the benefit of those who are unaware or are just interested in reading more, I’ll give a bit of a background… Kernel-based Virtual Machine (KVM) is a kernel module that was originally developed by an Israeli organisation called Qumranet to provide native virtualisation technology for Linux-based platforms; essentially turning the kernel into a Tier-1 hypervisor. It has since been ported to multiple other platforms and architectures other than 32/64-bit x86. It got initially adopted into the upstream Linux kernel as of 2.6.20 (back in 2007). Continue reading

Fixing VMware PVSCSI Kernel-Update Problem [RHEL5]

Recently, I worked on a customer problem which involved using the para-virtualisation drivers that VMware ship as part of their guest tools package for Linux operating systems. The VMware package provides a number of kernel modules, the most significant being their pvscsi (block-storage) and vmxnet3 (network) allowing enhanced performance in a virtual environment- rather than emulating SCSI or an ethernet adaptor such as Intel’s e1000- the choice of what to present to the virtual machine can be configured at any time, but if the drivers/modules aren’t available in the guest operating system, the devices cannot be used. Continue reading