Installation guide

Live migration is only possible between hosts with the same CPU type (that is, Intel to Intel

or AMD to AMD only).

For live migration, both hosts must have the same value set for the No eXecution (NX) bit,

either o n or o ff.

For migration to work, cache= no ne must be specified for all block devices opened in write

mode.

Warning

Failing to include the cache= no ne option can result in disk corruption.

St o rage rest rict io n s

There are risks associated with giving guest virtual machines write access to entire disks or

block devices (such as /d ev/sd b). If a guest virtual machine has access to an entire block

device, it can share any volume label or partition table with the host machine. If bugs exist

in the host system's partition recognition code, this can create a security risk. Avoid this risk

by configuring the host machine to ignore devices assigned to a guest virtual machine.

Warning

Failing to adhere to storage restrictions can result in risks to security.

SR- IO V rest rict io n s

SR-IOV is only thoroughly tested with the following devices (other SR-IOV devices may work

but have not been tested at the time of release):

Intel® 82576NS Gigabit Ethernet Controller (i g b driver)

Intel® 82576EB Gigabit Ethernet Controller (i g b driver)

Intel® 82599ES 10 Gigabit Ethernet Controller (i xg be driver)

Intel® 82599EB 10 Gigabit Ethernet Controller (i xg be driver)

Co re dumpin g rest rict io n s

Because core dumping is currently implemented on top of migration, it is not supported

when device assignment is in use.

4.2. Applicat ion rest rict ions

There are aspects of virtualization which make it unsuitable for certain types of applications.

Applications with high I/O throughput requirements should use the para-virtualized drivers for fully-

virtualized guests. Without the para-virtualized drivers certain applications may be unpredictable

under heavy I/O loads.

The following applications should be avoided due to high I/O requirements:

kd u mp server

Red Hat Ent erp rise Linux 6 Virt ualiz at ion Host Configurat ion and G uest Inst allat ion G uide