Users Guide

System Stops Responding Intermittently While Booting Into Red Hat Enterprise Linux 5 x86

64 Operating System

Description A defect in the Advanced Programmable Interrupt Controller (APIC) initialization code in Red

Hat Enterprise Linux 5 x86_64 may cause the system to stop responding during APIC

initialization.

The kernel may wait for a long time for the High Precision Event Timer (HPET) timer during

APIC initialization. If the NMI watchdog is enabled, the system may stop responding. If NMI

watchdog is not enabled, it may result in long boot-up delays.

Workaround Pass the nohpet parameter to the kernel command line at system boot.

X Window System Does Not Start On Systems With ATI ES1000 Chipset

Description On a Dell PowerEdge system with an ATI ES1000 chipset, the X Window System may fail to

start.

Workaround Add the line Option "DDCMode" "True" in the /etc/X11/xorg.conf file.

Example: The following file segment highlights the changed line:

Section "Device"

Identifier "Videocard0"

Driver "radeon"

Option "DDCMode" "True"

EndSection

System Stops Responding With Direct I/O On Pre-formatted Tape Media

Using Tar Commands

Description I/O operations with tape drives must occur in fixed block mode with a buffer size that is a

multiple of the pre-formatted block size.

If you are performing direct I/O operations with tape drives using commands like tar in fixed

block mode with buffer sizes that are not a multiple of the pre-formatted block size, a call trace

occurs and the system stops responding.

This issue is not specific to any HBA and occurs frequently when you are using the following

media:

• Pre-formatted new media

• Media formatted with different block size using a backup software

• Running tar commands after setting a different block size using mount command (mt)

Workaround This issue is fixed in a release of a dkms driver fix in the st driver, which is available at

dell.com/support.

Network Channel Bonding Packet Loss Under kernel-xen

Description When a network channel bond is configured under kernel-xen and if one of the link fails, a

packet loss occurs on the bonded interface.