I/O Subsystem

Summary of Change

The Dynamically Loadable Kernel Module (DLKM) infrastructure and I/O subsystem have been enhanced. Now DLKM-enabled drivers that control networking and I/O adapters can be dynamically loaded to and unloaded from the HP-UX kernel without rebuilding the kernel or rebooting the system.

The following DLKM infrastructure patches (or superseding patches) will be installed to enable DLKM of drivers: PHKL_36387, PHKL_36332, and PHCO_36371. These patches and other required patches are delivered in the FEATURE11i patch bundle on the September 2007 11i v3 OEUR media. A cold-install or an update to the September 2007 11i v3 OEUR will auto-select and install all required patches.

The HP-UX 11i v3 Application Software media for September 2007 will also include the FEATURE11i patches and I/O driver products that support DLKM of networking and I/O adapters. Selection of one or more I/O driver products will automatically select and install the required patches for the DKLM infrastructure.

To enable dynamic loading and unloading of a particular driver, you must also install the version of the driver that supports DLKM. For the following drivers, the version delivered with the September 2007 11i v3 OEUR supports DLKM:

See the release notes for the individual drivers to confirm which version supports dynamic loading and unloading.

Impact

The DLKM-enabled drivers that control networking and I/O adapters can be dynamically loaded to and unloaded from the HP-UX kernel without rebuilding the kernel or rebooting the system. This reduces system downtime to install driver updates or patches.

	IMPORTANT: If you have a system installed with the initial (February 2007) HP-UX 11i v3 release and you are not going to update to a subsequent OEUR, then you must install Software Distributor patch PHCO_36530, or install the B.11.31.0709 (or later) revision of the Software Distributor product, prior to updating a driver for DLKM enablement. Software Distributor is available at http://docs.hp.com/en/SD An updated or patched Software Distributor is needed for the required reboot on a system that had static drivers, after the installation of an I/O driver with DLKM functionality. A cold-install or an update (using Update-UX) to the September 2007 HP-UX 11i v3 OEUR will install the necessary version of the Software Distributor product for separate and later installations of I/O drivers with the DLKM functionality.

	NOTE: If you use swremove to remove a dynamically-loaded mass storage driver, the Critical Resource Analysis (CRA) may fail, causing SD to reboot the system unnecessarily. To avoid this CRA failure, install patch PHCO_36356 (or a superseding patch) before running swremove. If you remove any dynamically-loaded driver while it is in use, or if you remove a statically-loaded driver at any time, then a reboot will always be required. This is normal behavior under these conditions, and will not be affected by patch PHCO_36356.

Compatibility

There are no known compatibility issues.

Performance

There are no known performance issues.

Documentation

For information on loading and unloading kernel modules, see Chapter 10 of the HP-UX System Administrator's Guide: Configuration Management, available at http://docs.hp.com/en/oshpux11iv3.html.

For specifics on a particular driver, see the driver's release notes or the installation guide for its I/O card.

Obsolescence

Not applicable.