Installation guide

the kernel command line. ktune may not be suitable on some systems and workloads; as such,
you should test it comprehensively before deploying to production.
You can disable any configuration set by ktune and revert to your normall settings by simply
stopping the ktune service using service ktune stop (as root).
SGPIO Support for dmraid
Serial General Purpose Input Output (SGPIO) is an industry standard communication method
used between a main board and a variety of internal and external hard disk drive bay
enclosures. This method can be used to control LED lights on an enclosure through the AHCI
driver interface.
In this release, SGPIO support in dmraid is included as a technology preview. T his will allow
dmraid to work properly with disk enclosures.
GCC 4 .3
The Gnu Compiler Collection version 4.3 (GCC4.3) is now included in this release as a
Technology Preview. This collection of compilers include C, C++, and Fortran 95 compilers
along with support libraries.
Note that in the gcc4 3 packages, the default for the gnu89-inline option has been changed
to -fgnu89-inline, whereas upstream and future updates of Red Hat Enterprise Linux 5 will
default to -fno-gnu89-inline. This is necessary because many headers shipped as part of
Red Hat Enterprise Linux 5 expect GNU in-line semantics instead of ISO C99 semantics. T hese
headers have not been adjusted to request GNU in-line semantics through attributes.
Kernel T racepoint Facility
In this update, a new kernel marker/tracepoint facility has been implemented as a Technology
Preview. This interface adds static probe points into the kernel, for use with tools such as
SystemTap.
Device Failure Monitoring of RAID set s
Device Failure Monitoring, using the tools dmraid and dmevent_tool, is included in Red Hat
Enterprise Linux 5.3 as a Technology Preview. T his provides the ability to watch and report
device failures on component devices of RAID sets.
DFS
Starting with Red Hat Enterprise Linux 5.3, CIFS supports Distributed File System (DFS) as a
Technology Preview.
8. Resolved Issues
8.1. All Architectures
The data for TTY device activity reports was not generating correctly. Consequently, the command
sar -y failed, returning the error:
Red Hat Enterprise Linux 5 5.3 Release Notes
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