[summary nopav_in_dasd_param]
The "nopav" DASD parameter in &module_info_file_path; has no effect

[explanation nopav_in_dasd_param]
The &module_info_file_path; configuration file includes the "nopav"
parameter for the DASD device driver. This parameter suppresses parallel
access volume (PAV and HyperPAV) enablement for Linux instances that run in
LPAR mode. The "nopav" parameter has no effect for Linux on z/VM.

The "nopav" parameter can mislead administrators
into expecting that PAV is disabled.

[solution nopav_in_dasd_param]
Use the z/VM CP "QUERY PAV" command to find out which devices are set up
for PAV and HyperPAV. Use the z/VM CP "SET CU" command to disable PAV and
HyperPAV.

Use the configuration tools provided by your distribution to remove the "nopav"
parameter from your Linux on z/VM configuration or complete the following steps
to remove the parameter directly from the configuration files:

1. Open &module_info_file_path; with a text editor.

2. Find the following line:
#&module_information;

3. Remove "nopav" from this line.

4. Search &module_info_file_path; for other occurrences of "nopav" and,
   if applicable, remove these occurrences from all boot configurations
   for Linux on z/VM.

5. Save and close &module_info_file_path;.

If the "nopav" parameter was found in /proc/cmdline, you have to create a new
boot configuration and reboot Linux to remove this parameter. If you are
using "zipl" to create your boot configurations, you might have to first
remove "nopav" from the zipl configuration file, then run "zipl" to create a
new boot configuration, and then reboot Linux with the new boot configuration.

[reference nopav_in_dasd_param]
For more information about the "nopav" parameter, see the kernel or module
parameter section for the DASD device driver in
"Device Drivers, Features, and Commands".
This publication also has a general section about kernel and module parameters
and a section about the "zipl" command.
You can obtain this publication from
#www.ibm.com/developerworks/linux/linux390/documentation_dev.html

For more information about PAV and HyperPAV, see
"How to Improve Performance with PAV". You can obtain this publication from
#www.ibm.com/developerworks/linux/linux390/documentation_dev.html

For more information about the z/VM CP "QUERY PAV" and "SET CU" commands,
see "z/VM CP Commands and Utilities Reference". You can obtain this publication from
#www.ibm.com/vm/library

