12.2. Para-virtualization Restrictions and Support
This section outlines support restrictions and requirements for using para-virtualized drivers on Red Hat Enterprise Linux. What we support and the restrictions put upon support can be found in the sections below.
Support for para-virtualized drivers is available for the following operating systems and versions:
-
Red Hat Enterprise Linux 5.1
-
Red Hat Enterprise Linux 4 Update 6
-
Red Hat Enterprise Linux 3 Update 9
You are supported for running a 32 bit guest operating system with para-virtualized drivers on 64 bit Red Hat Enterprise Linux 5 Virtualization.
The table below indicates the kernel variants supported with the para-virtualized drivers. You can use the command shown below to identify the exact kernel revision currently installed on your host. Compare the output against the table to determine if it is supported.
# rpm -q --queryformat '%{NAME}-%{VERSION}-%{RELEASE}.%{ARCH}\n' kernel
The Red Hat Enterprise Linux 5 i686 and x86_64 kernel variants include Symmetric Multiprocessing(SMP), no separate SMP kernel RPM is required.
Take note of processor specific kernel requirements for Red Hat Enterprise Linux 3 Guests in the table below.
|
Kernel Architecture
|
Red Hat Enterprise Linux 3
|
Red Hat Enterprise Linux 4
|
Red Hat Enterprise Linux 5
|
|
athlon
|
Supported(AMD)
|
|
|
|
athlon-SMP
|
Supported(AMD)
|
|
|
|
i32e
|
Supported(Intel)
|
|
|
|
i686
|
Supported(Intel)
|
Supported
|
Supported
|
|
i686-PAE
|
|
|
Supported
|
|
i686-SMP
|
Supported(Intel)
|
Supported
|
|
|
i686-HUGEMEM
|
Supported(Intel)
|
Supported
|
|
|
x86_64
|
Supported(AMD)
|
Supported
|
Supported
|
|
x86_64-SMP
|
Supported(AMD)
|
Supported
|
|
|
x86_64-LARGESMP
|
|
Supported
|
|
|
Itanium (IA64)
|
|
|
Supported
|
Table 12.1. Supported kernel architectures for para-virtualized drivers
Important
The table above is for guest operating systems. AMD and Intel processors are supported for the Red Hat Enterprise Linux 5.1 host.
Finding which kernel you are using
Write the output of the command below down or remember it. This is the value that determines which packages and modules you need to download.
# rpm -q --queryformat '%{NAME}-%{VERSION}-%{RELEASE}.%{ARCH}\n' kernel
Your output should appear similar to this:
kernel-PAE-2.6.18-53.1.4.el5.i686
The name of the kernel is PAE(Physical Address Extension), kernel version is 2.6.18, the release is 53.1.4.el5 and the architecture is i686. The kernel rpm should always be in the format
kernel-name-version-release.arch.rpm
.
Para-virtualized device drivers can be installed after successfully installing a guest operating system. You will need a functioning host and guest before you can install these drivers.
Para-virtualized block devices and GRUB
GRUB
can not presently, access para-virtualized block devices. Therefore, a guest can not be booted from a device that uses the para-virtualized block device drivers. Specifically, the disk that contains the Master Boot Record(MBR), a disk containing a boot loader (GRUB), or a disk that contains the kernel initrd images. That is, any disk which contains the /boot directory or partition can not use the para-virtualized block device drivers.
For Red Hat Enterprise Linux 3 based guest operating systems you must use the processor specific kernel and para-virtualized driver RPMs as seen in the tables below. If you fail to install the matching para-virtualized driver package loading of the xen-pci-platform module will fail.
The table below shows which host kernel is required to run a Red Hat Enterprise Linux 3 guest on if the guest was compiled for an Intel processor.
|
Guest kernel type
|
Required host kernel type
|
|
ia32e (UP and SMP)
|
x86_64
|
|
i686
|
i686
|
|
i686-SMP
|
i686
|
|
i686-HUGEMEM
|
i686
|
Table 12.2. Required host kernel architecture for guests using para-virtualized drivers on Red Hat Enterprise Linux 3 for Intel processors
The table below shows which host kernel is required to run a Red Hat Enterprise Linux 3 guest on if the guest was compiled for an AMD processor.
|
Guest kernel type
|
Required host kernel type
|
|
athlon
|
i686
|
|
athlon-SMP
|
i686
|
|
x86_64
|
x86_64
|
|
x86_64-SMP
|
x86_64
|
Table 12.3. Required host kernel architectures for guests using para-virtualized drivers on Red Hat Enterprise Linux 3 for AMD processors
