My network doesn’t work..
Posted on March 26, 2010
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In revision 55 of the 2.6.9 kernel that RedHat released, a minor change in the way Ethernet cards are numbered was introduced. No big deal you may think, unless of course you upgrade your kernel from an older version, say, 42 to 89. Like I did. Once the system booted up, I found that only the bonded Ethernet device still worked. Eth0 and eth1 were bonded to bond0 and this was not even a public interface. After much investigation (pulling of hair) I found out that my system had renamed eth0 to eth1, eth1 to eth2, eth2 to eth3 and eth3 to eth0. As bond0 had eth0 and eth1, now eth1 and eth2 configured, one of the interfaced was still working and therefore bond0 could work. The other were quite obviously dead.
There is a simple cure out there. Add a flag to the kernel at boot time to stop re-ordering of the Ethernet cards. So at the end of the kernel line in the grub.conf add “pci=nobfsort”. Easy as that.
RHEL Kernel downgrades
Posted on March 25, 2010
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I recently had the misfortune to find a kernel upgrade on a RedHat Enterprise Linux 4 AS did not go as planned and I needed to back out to the old kernel version.
I found out a few things about up2date and rpm that day that hopefully will help you avoid the same pitfalls.
If you upgrade the kernel with a -U flag on rpm, then you will install the new kernel and, importantly remove the old version. This is not a way I would recommend, it makes roll backs a bit difficult. I would recommend downloading the kernel RPMs to your system and running rpm -ivhF kernel-X.rpm. This will install the new kernel and add it to your boot loader. In my case, grub. You can then reboot from the new kernel. Easy. If however the new kernel has an undesired effect, you can re-arrange your grub.conf file to boot from the old kernel, or, at the splash screen on boot up, interrupt the boot process and select the old kernel from the boot menu.
If however, like me, you used the -U flag and the old kernel is gone, you have a problem. I was fortunate to have access to the RedHat Network to download the older kernel revision that previously worked and used rpm -ivh –oldpackage to re-install it. I could then reboot from the old kernel.
Not quite..
Posted on March 12, 2010
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It’s not quite working yet. Cloud not showing up, nor twitter feed. Working….
And so it begins..
Posted on February 22, 2010
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..again.
I’ve cleared out my old blog and moved it to the root of my domain in a hope that I actually use it as much as I use twitter. There will of course be the usual settling down period whereby the little bugs get ironed out and I get back up and running.
I’ve got a few bugs in the Worpdress iphone app to work out too.
Fingers crossed. Here we go again.
Stephen
Hello world!
Posted on February 22, 2010
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Welcome to WordPress. This is your first post. Edit or delete it, then start blogging!