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Chapter 1. System Requirements
Virtualization is available with the KVM hypervisor for Red Hat Enterprise Linux 7 on the Intel 64 and AMD64 architectures. This chapter lists system requirements for running virtual machines, also referred to as VMs.
For information on installing the virtualization packages, see Chapter 2, Installing the Virtualization Packages.
1.1. Host System Requirements
Minimum host system requirements
- 6 GB free disk space.
- 2 GB RAM.
Recommended system requirements
- One core or thread for each virtualized CPU and one for the host.
- 2 GB of RAM, plus additional RAM for virtual machines.
- 6 GB disk space for the host, plus the required disk space for the virtual machine(s).Most guest operating systems require at least 6 GB of disk space. Additional storage space for each guest depends on their workload.
Swap spaceSwap space in Linux is used when the amount of physical memory (RAM) is full. If the system needs more memory resources and the RAM is full, inactive pages in memory are moved to the swap space. While swap space can help machines with a small amount of RAM, it should not be considered a replacement for more RAM. Swap space is located on hard drives, which have a slower access time than physical memory. The size of your swap partition can be calculated from the physical RAM of the host. The Red Hat Customer Portal contains an article on safely and efficiently determining the size of the swap partition: https://access.redhat.com/site/solutions/15244.
- When using raw image files, the total disk space required is equal to or greater than the sum of the space required by the image files, the 6 GB of space required by the host operating system, and the swap space for the guest.
Equation 1.1. Calculating required space for guest virtual machines using raw imagestotal for raw format = images + hostspace + swapFor qcow images, you must also calculate the expected maximum storage requirements of the guest
(total for qcow format), as qcow and qcow2 images are able to grow as required. To allow for this expansion, first multiply the expected maximum storage requirements of the guest
(expected maximum guest storage)by 1.01, and add to this the space required by the host
(host), and the necessary swap space
Equation 1.2. Calculating required space for guest virtual machines using qcow imagestotal for qcow format = (expected maximum guest storage * 1.01) + host + swap
Guest virtual machine requirements are further outlined in Chapter 7, Overcommitting with KVM.