Installation guide

Release Notes

To avoid this, set no_path_retry [N] in /etc/multipath.conf (where [N] is the

number of times the system should retry a path). When you do, remove the features "1

queue_if_no_path" option from /etc/multipath.conf as well.

If you need to use "1 queue_if_no_path" and experience the issue noted here, use dmsetup

to edit the policy at runtime for a particular LUN (i.e. for which all the paths are unavailable).

To illustrate: run dmsetup message [device] 0 "fail_if_no_path", where [device] is

the multipath device name (e.g. mpath2; do not specify the path) for which you want to change the

policy from "queue_if_no_path" to "fail_if_no_path".

• Enabling multiple installed versions of the same kernel module is not supported. In addition to this, a

bug in the way kernel module versions are parsed can sometimes result in enabling an older version

of the same kernel module.

Red Hat recommends that when you install a newer version of an installed kernel module, you

should delete the older one first.

• Executing kdump on an IBM Bladecenter QS21 or QS22 configured with NFS root will fail. To avoid

this, specify an NFS dump target in /etc/kdump.conf.

• IBM T60 laptops will power off completely when suspended and plugged into a docking station. To

avoid this, boot the system with the argument acpi_sleep=s3_bios.

• The QLogic iSCSI Expansion Card for the IBM Bladecenter provides both ethernet and iSCSI

functions. Some parts on the card are shared by both functions. However, the current qla3xxx and

qla4xxx drivers support ethernet and iSCSI functions individually. Both drivers do not support the

use of ethernet and iSCSI functions simultaneously.

Because of this limitation, successive resets (via consecutive ifdown/ifup commands) may hang

the device. To avoid this, allow a 10-second interval after an ifup before issuing an ifdown. Also,

allow the same 10-second interval after an ifdown before issuing an ifup. This interval allows

ample time to stabilize and re-initialize all functions when an ifup is issued.

• Laptops equipped with the Cisco Aironet MPI-350 wireless may hang trying to get a DHCP address

during any network-based installation using the wired ethernet port.

To work around this, use local media for your installation. Alternatively, you can disable the wireless

card in the laptop BIOS prior to installation (you can re-enable the wireless card after completing the

installation).

• Boot-time logging to /var/log/boot.log is not available in Red Hat Enterprise Linux 5.3.

• The system may not successfully reboot into a kexec/kdump kernel if X is running and using a

driver other than vesa. This problem only exists with ATI Rage XL graphics chipsets.

If X is running on a system equipped with ATI Rage XL, ensure that it is using the vesa driver in

order to successfully reboot into a kexec/kdump kernel.

• When using Red Hat Enterprise Linux 5.2 on a machine with an nVidia CK804 chipset installed, the

following kernel messages may appear:

kernel: assign_interrupt_mode Found MSI capability