April 2007

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I just got my server upgraded to Centos 5. CentOS 5 is the best operating system I’ve ever used. However, there are some not so fun issues with it. Specifically, if you want to transfer a xen domain from a previous version. Here’s what you need to know.

Redhat and CentOS do not include the xennet and xenblk drivers in initrd. This means that you will never be able to mount the root device. To fix this, make a new initrd with the command: mkinitrd /boot/initrd-xen-img –with=xennet –preload=xenblk . Make sure to add that file in the ramdisk option of the xen config.

The next trick is a doozy. The console device is no longer /dev/tty0 but is now /dev/console. I had to edit the /etc/inittab files on all of my vm’s to spawn a getty on /dev/console. This is the issue if everything looks good, but the machine won’t display a login. To fix this, either mount the xen disk and do the mods from dom0, or add the line extra = “1” in the cfg file to boot into single user mode and edit the file from there. I see alot of talk about /dev/xvc0 as the console, but haven’t had to use it yet.
Nash-hotplug is a little evil. The process was taking up 100% cpu on my jailtime CentOS 4.4 image. To fix this, I added a killall line to rc.sysinit. I was in rc.sysinit already since udev fails to start now. This isn’t a show stopper since all the needed device nodes were already created. If you need to create the device nodes yourself, try:

cd dev ; /dev/MAKEDEV null zero random urandom console tty pty hda xvd loop

The Debian image faired about the same. I had to fix the console as described above. There was another issue though. An error message with 4gb seg fixup in it kept appearing. The fix for that issue was to move or delete the /lib/tlb directory.

This is too hard for the normal person to figure out. If not for google, I would’ve been down for days.

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I’ve been playing more with cisco and Solaris lately.  One thing that I really like is how the configurations are created.  Take Solaris zones for example.  There is a zoncfg app that gives a prompt where settings can be added an removed easily.  The online help makes it easy to figure out even what the most obscure parameters are.  This is especially apparent with Cisco hardware.  A simple “?” gives every single option available.  There is no looking through man pages for really obscure stuff.  It is simply right in front of you.

It would be easy to implement this sort of configuration for other applications.  Let’s make a make believe program called config.  Config would have the following requirements:

All configuration files would have to be written as the same type of file.  For example XML.

Each program that is to work with config would have a definition file.  This file would have all parameters, objects, and help documentation defined.  The parameters would be in a hierarchy.  For example, ip address would be a parameter under network.  Let’s say these file has a .confdef extension and resides under /etc/confdef.  This file is where most of the magic would be.  GUI clients could be easily created to use this file.
conf would be able to modify multiple parameter types.  For example a boolean or a string.  Booleans could be modified through an enable or disable command.  Strings could be set through set and unset commands.

There would be a verify command in config that would make sure nothing was missing and report what was missing.  If mac_address is required, you will be notified.

Revision control would be built in.  One could create and restore backups easily.

Could you imagine if all of Unix took on the task of a SINGLE configuration format?  People who say unix is difficult may have to think a little before they speek.

Here’s how I imagine it.

config xorg
config xorg>configure display
config xorg:display>set resolution ?
possible completions are the screen resolution eg 1024×800
config xorg:display>set resolution=1024×800
config xorg:display>end
must set a default color bits (bpp) value
config xorg:display>set bpp=24
config xorg:display>end
config xorg>configure extensions
config xorg:extensions>enable aiglx
config xorg:extensions>enable dri
config xorg:extensions>configure dri
config xorg:extensions:dri>set mode=0666
config xorg:extensions:dri>end
config xorg:extensions>end
config xorg>save
Version Apr 13 15:20 for xorg configuration saved please type extra comments below
-> Enabled AIGLX and DRI.  Set resolution to 1024×800.
The line above is automatically generated ^D
config xorg>commit
Version Apr 13 15:20 is now active configuration for xorg
Utopia right?

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I’ve been an off and on follower of WWE wrestling. Yes, I know it’s fake. I like to watch the athletic moves that they pull off. My wife bought me tickets for my birthday and we attended the RAW showing on March 26. Here’s a few observations.

They don’t allow cameras into the event. I wanted to take some pictures to remember the event by, but couldn’t. The security guard stated that the event was a production. I thinks it is more of a seen it once seen it a thousand times issue. If they allow pictures to be taken, why come back?

The event really did feel like a production, specifically, a play. The different wrestlers seemed to be part of acts that they played roles in. The audience was simply an audience and didn’t play a role at all in the play.
The wrestlers are big people. The don’t look bigger in real life then they do on television. I came within a couple of feet of the Great Kahli. That guy is big.

The moves the wrestler’s perform are directed towards the camera. I was sitting on the opposite side of the ring. The moves looked much more staged from that angle. Without the camera shake that you get when watching on television, the moves don’t look that painful at all.

I was lucky enough to be on the kiss cam. That’s right, I kissed my wife while on the big screen. I’m looking to see if that part was televised. My climb to fame continues.

It wasn’t a great time, but it was a good birthday present. The audience participation was too low for it to be something I’d be interested in doing again soon.

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