20.2. Operating System Booting
There are a number of different ways to boot virtual machines each with their own pros and cons. Each one is described in the sub-sections that follow and include: BIOS boot loader, host physical machine boot loader, and direct kernel boot.
20.2.1. BIOS Boot loader
Booting through the BIOS is available for hypervisors supporting full virtualization. In this case the BIOS has a boot order priority (floppy, harddisk, cdrom, network) determining where to obtain/find the boot image. The OS section of the domain XML contains the information as follows:
... <os> <type>hvm</type> <loader>/usr/lib/xen/boot/hvmloader</loader> <boot dev='hd'/> <boot dev='cdrom'/> <bootmenu enable='yes'/> <smbios mode='sysinfo'/> <bios useserial='yes' rebootTimeout='0'/> </os> ...
Figure 20.2. BIOS boot loader domain XML
The components of this section of the domain XML are as follows:
Table 20.2. BIOS boot loader elements
|Specifies the type of operating system to be booted on the guest virtual machine. |
|refers to a piece of firmware that is used to assist the domain creation process. It is only needed for using Xen fully virtualized domains.|
|takes one of the values:|
|determines whether or not to enable an interactive boot menu prompt on guest virtual machine startup. The |
|determines how SMBIOS information is made visible in the guest virtual machine. The |
|This element has attribute |