Chapter 2. Understanding the Red Hat Enterprise Virtualization Hypervisor

This chapter provides a brief introduction to the technical aspects of the Red Hat Enterprise Virtualization Hypervisor. This chapter is written to assist technical users with identifying issues and understanding the Red Hat Enterprise Virtualization Hypervisor.
The Red Hat Enterprise Virtualization Hypervisor is derived from the Managed Node component of the oVirt project. While the core technology of oVirt Managed Node is used, the Red Hat Enterprise Virtualization Hypervisor incorporates its own management communications stack. For more information on the oVirt project, visit oVirt.org.

2.1. Red Hat Enterprise Virtualization Hypervisor directories

Red Hat Enterprise Virtualization Hypervisors have a directory layout that varies from Red Hat Enterprise Linux and other Linux Distributions. All Red Hat Enterprise Hypervisors have the following directories:
/config
The /config directory contains all persistent configuration files for the Red Hat Enterprise Virtualization Hypervisor. These files control passwords, storage configuration, security and networking.
The /config directory must be at least 5MB.
/boot
The /boot directory contains the boot loader, the kernel and the initramfs file.
The /boot directory is not mounted by default. The ovirt-config-boot boot command mounts the partition only when needed for an upgrade.
The /boot directory must be exactly 50MB.
/liveos
The /liveos directory contains a compressed Red Hat Enterprise Virtualization Hypervisor live CD image. The Red Hat Enterprise Virtualization Hypervisor boots and runs from the ISO image file in this directory.
The /liveos directory is not normally visible on the running system. This is the folder containing the livecd ISO. During an upgrade /dev/HostVG/Root is temporarily mounted to /liveos
/var/log
Contains all the logs for the Hypervisor.
The log directory must be at least 2048MB. The default size of the log directory is 2048MB.
/var/log/core
Contains core dumps from the Hypervisor which can be used for debugging and support.
/var/vdsm/
The /var/vdsm/ is used by the vdsmd daemon for storing volatile data, including /var/vdsm/ts which stores vdsm truststore.
/rhev/data-center
Contains links to Storage Domains.
/data
This directory contains virtual machine cache data and other miscellaneous files.
The data partition must be at least as large as the RAM on the host system plus an additional 512MB in size. A data partition at least one and a half times as large as the RAM on the host system is recommended.
The default size for the data partition is the remaining available disk space.