I/O errors occur on iSCSI devices during a system shutdown on RHEL5.5 and its beta version

Issue

• When a system shutdown is invoked and if there is a symbolic link either in /etc/rc0.d/ or /etc/rc6.d/, network device will also be shutdown by the "network" script in /etc/rc.d/init.d/. 

• If iSCSI devices are used, however, the system will still generate I/Os to the devices, and the I/Os will end up with an error because the network is not available anymore.