Chapter 1. System requirements

This chapter lists system requirements for successfully running virtualization with Red Hat Enterprise Linux.
The requirements for virtualization vary depending on the type of hypervisor. The Kernel-based Virtual Machine (KVM) and Xen hypervisors are provided with Red Hat Enterprise Linux 5. Both support Full virtualization. The Xen hypervisor also supports Para-virtualization.
For information on installing the virtualization packages, read Chapter 6, Installing the virtualization packages.

Minimum system requirements

  • 6GB free disk space.
  • 2GB of RAM.

Recommended system requirements

  • 6GB plus the required disk space recommended by the guest operating system per guest. For most operating systems more than 6GB of disk space is recommended.
  • One processor core or thread for each virtualized CPU and one for the hypervisor.
  • 2GB of RAM plus additional RAM for guests.

Note

KVM can overcommit physical resources for guests. Overcommiting resources means the total virtualized RAM and processor cores used by the guests can exceed the physical RAM and processor cores on the host. For information on safely overcommitting resources with KVM, see Section 33.4, “Overcommitting Resources”.
Xen para-virtualization requirements

Para-virtualized guests require a Red Hat Enterprise Linux 5 installation tree available over the network using the NFS, FTP or HTTP protocols.

Xen full virtualization requirements

Full virtualization with the Xen Hypervisor requires:

  • an Intel processor with the Intel VT extensions, or
  • an AMD processor with the AMD-V extensions, or
  • an Intel Itanium processor.
See Section 33.6, “Verifying virtualization extensions” to determine if your processor has the virtualization extensions.
KVM requirements

The KVM hypervisor requires:

  • an Intel processor with the Intel VT and the Intel 64 extensions, or
  • an AMD processor with the AMD-V and the AMD64 extensions.
See Section 33.6, “Verifying virtualization extensions” to determine if your processor has the virtualization extensions.
Storage support

The supported guest storage methods are:

  • Files on local storage
  • Physical disk partitions
  • Locally connected physical LUNs
  • LVM partitions
  • iSCSI and Fibre Channel based LUNs

Important

File-based guest images are stored in the /var/lib/libvirt/images/ directory by default. If you choose to use a different directory you must label the new directory according to SELinux policy. See Section 19.2, “SELinux and virtualization” for details.