Users Guide

18–Troubleshooting
NPAR
300 BC0054508-00 M
Problem: iSCSI-Offload boot from SAN fails to boot after installation.
The iSCSI boot from SAN process is divided into two parts: pre switch-root and
post switch root.
During pre switch-root, when the drivers load, the open-iSCSI tool iscsistart
establishes the connection with the target and discovers the remote LUN. Then
iscsistart starts a session using the iBFT information.
The iscsistart utility program is not run to manage connection with target. (Its
primary use is to start sessions used for iSCSI root boot.)
After the post switch-root, as a part of initialize boot process, the open-iscsi tool
iscsid takes over the pre switch-root iSCSI connection. Therefore, iscsid manages
the iscsi connection with target during recovery.
There is gap between when the pre switch-root iscsistart establishes the
connection and when iscsid takes over iSCSI connection. During this time, the OS
boot process no way to recovery the iSCSI connection. In some cases, the bnx2x
NIC interface’s link 'flaps' during this gap, the iSCSI connection is interrupted, and
the iSCSI connection recovery or retries fail.
Solution: Avoid the bnx2x NIC interface’s link flap, load the bnx2x driver with the
module parameter disable_tpa=1. Set this parameter through either a kernel
grub command line or /etc/modprobe.d/bnx2x.conf file configuration.
NPAR
Problem: The following error message appears if the storage configurations are
not consistent for all four ports of the device in NPAR mode:
PXE-M1234: NPAR block contains invalid configuration during boot.
A software defect can cause the system to be unable to BFS boot to an iSCSI or
FCoE target if an iSCSI personality is enabled on the first partition of one port,
whereas an FCoE personality is enabled on the first partition of another port. The
MBA driver performs a check for this configuration and prompts the user when it is
found.
Solution: If using the 7.6.x firmware and driver, to workaround this error,
configure the NPAR block such that if iSCSI or FCoE is enabled on the first
partition, the same must be enabled on all partitions of all four ports of that device.