User manual REDHAT ENTERPRISE LINUX 5.4 RELEASE NOTES

[. . . ] Red Hat Enterprise Linux 5. 4 Release Notes Release Notes for all architectures. This material may only be distributed subject to the terms and conditions set forth in the Open Publication License, V1. 0 or later (the latest version of the OPL is presently available at http://www. opencontent. org/openpub/). Red Hat and the Red Hat "Shadow Man" logo are registered trademarks of Red Hat, Inc. All other trademarks referenced herein are the property of their respective owners. 1801 Varsity Drive Raleigh, NC 27606-2072 USA Phone: +1 919 754 3700 Phone: 888 733 4281 Fax: +1 919 754 3701 PO Box 13588 Research Triangle Park, NC 27709 USA Abstract This document details the Release Notes for Red Hat Enterprise Linux 5. 4. [. . . ] With this update, CPI data can now be associated with a 41 Red Hat Enterprise Linux instance. (BZ#475820) For more information on CPI refer to the Device Drivers, Features, and Commands document 42 · Fibre Channel Protocol (FCP) performance data can now be measured on Red Hat Enterprise Linux 43 instances on the IBM System z platform. (BZ#475334) Metrics that are collected and reported on include: · Performance relevant data on stack components such as Linux devices, Small Computer System Interface (SCSI) Logical Unit Numbers (LUNs) and Host Bus Adapter (HBA) storage controller information. · Per stack component: current values of relevant measurements as throughput, utilization and other applicable measurements. · Statistical aggregations (minimum, maximum, averages and histogram) of data associated with I/ O requests including size, latency per component and totals. · Support has been added to the kernel to issue EMC Symmetrix Control I/O. This update provides the ability to manage EMC Symmetrix storage arrays with Red Hat Enterprise Linux on the IBM 44 System z platform. (BZ#461288) · A new feature has been implemented in the kernel to perform an Initial Program Load (IPL) on a Red Hat Enterprise Linux virtual machine immediately following a kernel panic and 45 dump. (BZ#474688) · Hardware that supports the configuration topology facility passes the system CPU topology information to the scheduler, allowing it to make load balancing decisions. On machines where I/O interrupts are unevenly distributed, CPUs that are grouped together and get more I/O interrupts than others will tend to have a higher average load, creating performance issues in some cases. With this update, CPU topology support is disabled by default, and the kernel parameter "topology=on" has been added to allow this feature 46 to be enabled. (BZ#475797) · New kernel options can now be added using the IPL command without modifying the content of the CMS parmfile, allowing for temporary overwriting of kernel options that are already provided by the parmfile. The entire boot command line can be replaced with the VM parameter string, bypassing any kernel options from the parmfile. Furthermore, customers can create new Linux Named Saved 47 Systems (NSS) on the CP/CMS command line. (BZ#475530) · The qeth driver has been updated with HiperSockets Layer3 support for IPv6. (BZ#475572) For further details on this feature, refer to the "qeth device driver for OSA-Express (QDIO) and HiperSockets" chapter in IBM's "Device Drivers, Features, and Commands" book located at: http:// www. ibm. com/developerworks/linux/linux390/october2005_documentation. html · Starting with z9 HiperSocket firmware returns the version string in a different format. This change resulted in missing mcl_level information in the qeth status message issued during online setting 48 10 Kernel Updates of the device. The updated qeth driver now correctly reads the new version string format of 49 HiperSockets, allowing for a standardization of output format. (BZ#479881) · In Red Hat Enterprise Linux 5. 4, the s390utils package has been rebased to version 1. 8. 1. For a full list of features that this rebase provides, please refer to the Package Updates section of the 50 51 Technical Notes . (BZ#477189) · In the kernel, a sysfs interface has been implemented to associate actions to shutdown triggers. For more details on this feature, refer to the "Shutdown actions" chapter in IBM's "Device Drivers, Features, and Commands" book located at: http://www. ibm. com/developerworks/linux/linux390/ development_documentation. html 8. General Kernel Feature Support · Asymmetric Logical Unit Access (ALUA) support in device-mapper-multipath has been updated, adding explicit ALUA support for Clariion storage. [. . . ] · A bug that caused kernel panics with the QLogic 2472 card is now fixed. · The stop_firmware command is no longer retried if the first attempt results in a times out. · The sector mask value is no longer based on the fixed optrom size. · A bug that caused frequent path failures during I/O on multipathed devices is now fixed. [. . . ]