Support Notes for Red Hat Enterprise Linux 5.1 for HP Integrity Servers

29. After installing the operating system, the system just installed may not boot or a previously
installed system may boot instead. To resolve this problem, enter the following commands
in the EFI shell:
Shell> reconnect -r
Shell> map -r
Then reboot. This can be done by exiting the shell (using the exit command) and reselecting
the EFI boot menu entry.
If this does not resolve the problem, try turning off the boot entry caching with the EFI
ioconfig command:
Shell> ioconfig fast_init off
Fast initialization: Disabled
30. To create a system that can boot either RHEL 4.5 or RHEL 5.1, the RHEL 4.5 system must
be installed and configured before installing the RHEL 5.1system.
31. On RHEL 5.1, the CPU frequency scaling subsystem of the kernel (cpufreq) controls
performance states (P-states). The operating system uses P-states to manipulate a CPU's
core frequency, lowering the frequency when the system is not under load thus reducing
the platform's power consumption. The frequency scaling subsystem of RHEL5.1 has locking
issues. The more logical processors a platform contains the more likely the occurrence of
encountering the locking issues. When encountered, the CPU executing the process that was
interacting with the frequency scaling subsystem will hang indefinitely.
HP recommends disabling P-states on RHEL 5.1.
To disable the frequency scaling subsystem of the kernel, follow these steps:
1. Enter the cpuconfig command at the EFI shell's command prompt prior to
installing/booting Linux:
cpuconfig pstates off
2. After entering the cpuconfig command, enter a reset for the disabling of P-states
to take effect.
These steps should be performed prior to installing, and or booting, Linux.
HP expects this issue to be corrected in a future release of RHEL 5.
32. Installation of RHEL 5.1 on HP BL860c and BL870c Blade Servers with multiple HP NC364m
Quad Port 1GbE BL-c Adapters (447883-B21) installed may hang during the IP information
request stage. This hang occurs with the built-in Broadcom 5704 Ethernet ports within the
RHEL 5.1 installer.
The problem is that users are unable to bring up the built-in networking ports on the first
attempt. There are three possible workarounds:
a. Retry configuring the built-in port from the the Configure TCP/IP screen in the RHEL
5.1 installer.
b. Reboot the system and perform the installation with Ethernet autonegotiation disabled.
To do this, use the parameter ethtool="autoneg=off" when booting from the
installation media. This will not affect the final installed system
c. Perform the network install using one of the ports from the HP NC364m Quad Port
1GbE BL-c Adapters.
This problem does not affect the final installed system; it is only a network installation issue.
This problem will be fixed in a future RHEL 5 release.
33. If you have an AD385A 10GbE card in your configuration, ethtool may not always provide
the correct link status. In some situations, ethtool may indicate that the link for this card
is up after it has been taken down. This problem will be fixed in a future release.
Known Issues 11