When Red Hat Enterprise Linux runs in in LPAR, it attempts to acquire information about all devices granted to the LPAR. This could result in an out-of-memory condition on installations with a large number of devices. However, this can be avoided with the use of the cio_ignore kernel parameter. Setting the cio_ignore parameter creates a blacklist and prevents the kernel from creating data structures for the specified devices.

This parameter can be passed at boot time using the interactive boot menu or made more persistent by setting the /etc/zipl.conf file.

For a complete description of the cio_ignore kernel parameter, refer to Chapter 28: Selected kernel parameters of Device Drivers, Features, and Commands. This document can be downloaded here:

http://download.boulder.ibm.com/ibmdl/pub/software/dw/linux390/docu/l26bdd03.pdf