On Thu, 2014-03-13 at 16:34 -0400, Larry Linder wrote:
> On one of our development systems the Internet quit working after a power 
> failure and a reboot.   We suspect that that a new kernel was downloaded by 
> Yum and never took effect till a reboot occurred sometime later.
> History:
> We know that the realtech driver for chip set RTL 8111/8168B works with SL 
> 5.4 -> 5.10.  The problem is with SL 6.1 - 6.5.  Same box same hardware.
> 
> A long time ago we installed a special kernel from ELRepo.org to fix the 
> problem with SL 6.4.
> 
> SL 6.4 later was updated to SL 6.5 and still no Ethernet - 
> 
> ifconfig shows that it can receive but not transmit as before.
> 
> Would it be appropriate to reinstall the 
> kernel-lt-3.10.32-1.el6.elrepo.x86_64.rpm     date  28 Feb. 14
> to fix the problem.
> 
> Second question: How do you turn automatic updates OFF.

Normally the kernel is excluded from automatic updates so I would
say that it is unlikely to have been an automatically installed
kernel that has caused this.

The file /etc/sysconfig/yum-autoupdate has an setting for controlling
automatic updates, and it also has the setting for which RPMs are
excluded from being automatically updated. I would check this file and
the yum.log to further investigate. And, as Connie suggested, you
should be able to boot from an older kernel at the grub menu.

-- 
Mark Whidby
Infrastructure Coordinator (Unix)
Physics/Chemistry/EAES/Mathematics Team
IT Services, Faculty of Engineering and Physical Sciences