3.9. Devices

ipmitool component
Not specifying the -N option when setting retransmission intervals of IPMI messages over the LAN or LANplus interface may cause various error messages to be returned. For example:
~]# ipmitool -I lanplus -H $HOST -U root -P $PASS sensor list
Unable to renew SDR reservation
Close Session command failed: Reservation cancelled or invalid

~]# ipmitool -I lanplus -H $HOST -U root -P $PASS delloem powermonitor
Error getting power management information, return code c1
Close Session command failed: Invalid command
ipmitool component
The ipmitool may crash in certain cases. For example, when an incorrect password is used, a segmentation fault occurs:
~]# ipmitool -I lanplus -H $HOST -U root -P wrongpass delloem powermonitor
Error: Unable to establish IPMI v2 / RMCP+ session
Segmentation fault (core dumped)
kernel component,
Unloading the be2net driver with a Virtual Function (VF) attached to a virtual guest results in kernel panic.
kernel component
The Brocade BFA Fibre Channel and FCoE driver does not currently support dynamic recognition of Logical Unit addition or removal using the sg3_utils utilities (for example, the sg_scan command) or similar functionality. Please consult Brocade directly for a Brocade equivalent of this functionality.
kernel component
iSCSI and FCoE boot support on Broadcom devices is not included in Red Hat Enterprise Linux 6.3. These two features, which are provided by the bnx2i and bnx2fc Broadcom drivers, remain a Technology Preview until further notice.
kexec-tools component
Starting with Red Hat Enterprise Linux 6.0 and later, kexec kdump supports dumping core to the Brtfs file system. However, note that because the findfs utility in busybox does not support Btrfs yet, UUID/LABEL resolving is not functional. Avoid using the UUID/LABEL syntax when dumping core to Btrfs file systems.
busybox component
When running kdump in a busybox environment and dumping to a Btrfs file system, you may receive the following error message:
/etc/kdump.conf: Unsupported type btrfs
However, Btrfs is supported as a kdump target. To work around this issue, install the btrfs-progs package, verify that the /sbin/btrfsck file exists, and retry.
trace-cmd component
The trace-cmd service does start on 64-bit PowerPC and IBM System z systems because the sys_enter and sys_exit events do not get enabled on the aforementioned systems.
trace-cmd component
trace-cmd's subcommand, report, does not work on IBM System z systems. This is due to the fact that the CONFIG_FTRACE_SYSCALLS parameter is not set on IBM System z systems.
tuned component
Red Hat Enterprise Linux 6.1 and later enter processor power-saving states more aggressively. This may result in a small performance penalty on certain workloads. This functionality may be disabled at boot time by passing the intel_idle.max_cstate=0 parameter, or at run time by using the cpu_dma_latency pm_qos interface.
libfprint component
Red Hat Enterprise Linux 6 only has support for the first revision of the UPEK Touchstrip fingerprint reader (USB ID 147e:2016). Attempting to use a second revision device may cause the fingerprint reader daemon to crash. The following command returns the version of the device being used in an individual machine:
~]$ lsusb -v -d 147e:2016 | grep bcdDevice
kernel component
The Emulex Fibre Channel/Fibre Channel-over-Ethernet (FCoE) driver in Red Hat Enterprise Linux 6 does not support DH-CHAP authentication. DH-CHAP authentication provides secure access between hosts and mass storage in Fibre-Channel and FCoE SANs in compliance with the FC-SP specification. Note, however that the Emulex driver (lpfc) does support DH-CHAP authentication on Red Hat Enterprise Linux 5, from version 5.4. Future Red Hat Enterprise Linux 6 releases may include DH-CHAP authentication.
kernel component
The recommended minimum HBA firmware revision for use with the mpt2sas driver is "Phase 5 firmware" (that is, with version number in the form 05.xx.xx.xx). Note that following this recommendation is especially important on complex SAS configurations involving multiple SAS expanders.