I really did like my Canon G7 but since I broke it I've been trying to figure out what to do. Canon will fix it for $160 but I've not had the time to send it off. They'll replace it for $275 if I send the old one in but again I don't know how long that takes. I have no problem replacing the camera if there is an alternative. I thought Nikons P series camera may be a contender but all the reviews have shown it to be dog slow. Before buying the G7 I seriously looked over the Panasonic DMC-LX1 but reviews showed it have outrageous overpowering noise cancelation to the point that any photo taken above ISO 200 looked like mud. The Panasonic DMC-LX2 came out with the hope that they'd fixed the noise situation but they only slightly improved it. Again any photo taken at ISO 100/200 looked as good as a Sony or Canon but as soon as that ISO reached 400 it was all over. I'm not sure why Panasonic's sensor is so noisy but it's really bad. Let it be known that on paper the Panasonic cameras have been virtually perfect for my needs in my eyes.

The reason I'm dwelling on the LX series once again is because Panasonic just announced the DMC-LX3. As usual the paper specs are just about ideal for what I want to do. The question is can it take photos without messing them up intentionally.

Here's what I like about it compared to the G7:

• Large 1/1.63 sensor for the camera size. This is larger than the G7s 1/1.8
• Shoots in raw - G7 does with chdk hack
• Built in 24 mm wide angle. Even with the huge wide angle adapter my G7 was 28mm
• Fast F2.0-2.8 Leica lens - G7 f2.8-4.8
• Hot shoe for flash
• 720p video at 24 fps
• 2.5 fps continuous drive (8 frames max)
• high burst mode of 6 frames a second, I don't know the limit
• 3.0" LCD with 480,000 pixels - G7 2.5" with 200,000 pixels
• Lighter, 9.3 oz - G7 13 oz
• Smaller, half inch smaller in two dimensions 4.3x2.4x1.1 - G7 4.2x2.8x1.7
• Extra wide angle conversion lens takes it to 18 mm
• All manual functions - aperature and shutter priority
• Has a grip

•  

How to move from a tap:aio file to an LVM Logical Volume.

In Xen we can provide virtualized hard drives several different ways. It's not uncommon to create a large empty file using dd and then specify it as the hard drive like this.

wget http://voxel.dl.sourceforge.net/sourceforge/asteriskathome/trixbox-2.6.1-i386.iso

First we'll need to make a disk image for our VOIP server.

dd if=/dev/zero of=/srv/xen/voipserver.img bs=1024 count=5000000

NOTE! I have not tried this rpm kernel! Until I get to it take it as a howto with no possible gaurantee. I will get to testing it extensively the first week of September as I'm on vacation.

I just did a howto on compiling Xen 3.2.1 for CentOS5 but then I found this kernel and Xen rpms that you can just download and install.

For x86_64

1. wget http://www.halsign.com/files/TurboGate-HTools-1.2-rhel5-x86_64.tar
2. tar -xvpf TurboGate-HTools-1.2-rhel5-x86_64.tar
3. cd TurboGate-HTools-1.2-rhel5-x86_64/
4. rpm -ivh *.rpm
5. reboot and select new kernel at grub prompt

For i386

1. wget http://www.halsign.com/files/TurboGate-HTools-1.2-rhel5-i386.tar
2. tar -xvpf TurboGate-HTools-1.2-rhel5-i386.tar
   
3. cd TurboGate-HTools-1.2-rhel5-i386/
4. rpm -ivh *.rpm
5. reboot and select new kernel at grub prompt

I haven't as of yet used this new kernel and Xen but it might make it a lot easier than compiling Xen 3.2.1 from scratch.

I thought about updating this to include Xen 3.3 but in all reality the gitco repositories work great for i386 and x86_64 so I don't see a reason to compile xen. However, I'm leaving this up in case someone wants to use it as a loose guide to compile xen 3.3.1.

CentOS 5.2/RHEL 5.2 comes with a very highly modified Xen 3.03 which if I'm correct is in fact Xen 3.1 backported. If you want to use the latest Xen 3.2.1 you need to update the hypervisor. This tutorial is for x86_64 because that's what I'm running on grantmcwilliams.com. If you want the 32 bit version modify the appropriate paths and file names.

1. rpm -i http://bits.xensource.com/oss-xen/release/3.2.0/centos-5.1/xen-3.2.0-0xs.centos5.src.rpm 2> /dev/null
2. cd /usr/src/redhat/SOURCES ; wget http://bits.xensource.com/oss-xen/release/3.2.1/xen-3.2.1.tar.gz
3. vi ../SPECS/xen.spec
4. - Change "Version: 3.2.0" to "Version 3.2.1"
5. - Change "Source0: xen-3.2.0.tar.gz" to "Source0: xen-3.2.1.tar.gz"
6. - Uncomment "# /usr/lib/xen/boot/hvmloader"
7. yum -y install transfig texi2html tetex-latex gtk2-devel libaio-devel gnutls-devel
8. cd /usr/src/redhat/SPECS ; rpmbuild -ba ./xen.spec
9. Grab some coffee...

... after the rpms are built do this

1. vi /etc/yum.conf and temporarily set "gpgcheck=0" to "gpgcheck=1" since RPMs aren't signed.
2. cd /usr/src/redhat/RPMS/x86_64 ; yum -y install xen-3.2.1-0xs.x86_64.rpm xen-libs-3.2.1-0xs.x86_64.rpm xen-devel-3.2.1-0xs.x86_64.rpm
3. vi /etc/yum.conf and set gpgcheck back to "gpgcheck=1".
4. edit /boot/grub/grub.conf and switch all references of /boot/xen-3.1.. to /boot/xen-3.2..

Now you can reboot and enjoy your new Xen 3.2.1.

If you're moving from a real server installation to a VirtualBox virtualized configuration you may want to take your real physical disk and just turn it into a virtual disk. There are advantages to creating a new disk and rsyncing your OS into it but this tutorial will show you how to make an exact copy of it. Note the exact copy will be the same size as the real physical disk so make sure you have enough drive space. This is most useful for Operating System images with shared storage for data. I wouldn't advise anyone to make a 1TB copy of their new drive and turn it into a VDI file!

To get the image from the disk use the dd command.

1. dd if=/dev/hda of=./hda.img
2. VBoxManage convertdd hda.img hda.vdi

grant@workstation:~$ dd if=/dev/hda of=./hda.img

grant@workstation:~$ VBoxManage convertdd hda.img hda.vdi
VirtualBox Command Line Management Interface Version 1.6.0
(C) 2005-2008 Sun Microsystems, Inc.
All rights reserved.

Converting VDI: from DD image file="hda.img" to file="hda.vdi"...
Creating fixed image with size 1024966656 bytes (978MB)...

This will make an exact copy of /dev/hda to the raw image file hda.img. Then VBoxManage will convert the raw disk hda.img to hda.vdi for use with VirtualBox.

It seems the recent heat wave has wreaked havoc on my web server so I've been experiencing outages on grantmcwilliams.com. A new server has been built with a billion fans (sounds like the boeing plant) and I'm moving all virtual hosts to it now. I figure I'l have it up in the next couple of days. A virtualized Zimbra server is already up and running and now I'm building the webserver.

Thanks for your patience,

Grant

In setting up a Xen virtualized web server with about 15 GB of static files I questioned the wisdom of using a disk image as apposed to LVM. I read a bunch of forums about which is better and it seems the disk images are easier to manage because you can just copy to make backups etc.. LVM you just can't move it and pop it up whereever you want but you have more flexibility in resizeing and backing them up within the host OS. However what I didn't find on the forums is performance tests. People theororized about the speed difference but it seems nobodies sat down and done some tests. It's my goal that after summer vacation to put together a performance whitepaper comparing all the virtual machine solutions. For now I'll just put up xen disk images against LVM.

So I created a 10 GB empty disk image using dd and I created a 10 GB LVM Logical volume and assigned both of them to the domU.

name = "centtest"
memory = "512"
disk = [ 'tap:aio:/srv/xen/centos5.img,xvda,w', 'tap:aio:/srv/xen/centtest.img,xvdb,w', 'phy:/dev/vgsys/lvtest,xvdc,w' ]
vif = [ 'bridge=xenbr0', ]
bootloader="/usr/bin/pygrub"
vcpus=1
on_reboot = 'restart'
on_crash = 'restart'