nTh among all

I’m trying out F16 as a dom0 from the beginning. No upgrades from F15 this time. So far, it’s generally ok.

The install (from the netinstall ISO) was straightforward. Only issue was that F16 strongly recommends that a BIOS boot partition be present. (Read: Requires it unless you pass a nogpt option to the kernel boot line when installing.) Unlike in the F16 domU, I need grub2 to be working so I can boot, so I added the partition.

However, it’s subject to some strict size limits – between 1-2MB. 1MB is recommended, though I put 2MB and it seems to boot fine. If you try anything larger though, you get this error: (Why it says allowable size between 0MB-2MB is a mystery though. 1MB is the minimum size for all partitions.)

So, other than that install issue, there was nothing of note. Now, in the working system, I did a yum install xen, and yum pulled down xen & the dependencies and installed them. As part of the install, it also regenerated grub.cfg. So don’t press Ctrl+C even though it looks like yum’s frozen. It isn’t.

One annoyance: The generated file is filled with Xen entries. You can either ignore them, and select Xen 4.1.2, or patch GRUB2 as specified here to get rid of the spurious entries. (No idea when the patched version will go into the repos.)

Next is networking. On my desktop, I have a strange Ethernet driver – it shows up as p34p1. No clue why, and it’s given me no end of trouble, particularly where NetworkManager attempts to seize control despite being specified as “NM_CONTROLLED=NO”.

But that’s neither here nor there. On the testbed, getting networking is trivial, just a matter of creating the bridge definition, and modifying the existing network adapter definition.

In /etc/sysconfig/network-scripts/, the existing file is named ifcfg-<network_adaptor>. (The one other than ifcfg-lo.) In my case, it was ifcfg-em1. If you have special requirements, I’d recommend Google (which threw up this as the first result, and it seems pretty good), but if you’re using DHCP (if you don’t know what you’re using, chances are you are using DHCP), you just need to add the following to the new file ifcfg-br0 with your favourite text editor:

DEVICE=br0
TYPE=Bridge
BOOTPROTO=dhcp
ONBOOT=yes
DELAY=0
NM_CONTROLLED=NO

And append BRIDGE=br0 to your respective network adaptor definition file (i.e. ifcfg-em1). (With Vim or echo >> file, it doesn’t matter.)

Reboot, and the system seems to be up and running Xen. (Verify with a xl info)