Tech

As a strike against the industry leading VMWare, Citrix releases it's Xen Enterprise Virtualization platform to the public for free. Note this does not mean it's been released OpenSource as the Xen hypervisor is, it's just free to download and use on as many installations as you like. The difference is that it's free as in beer, not as in freedom. If Citrix wanted to change the license back to pay only after it hooks a million customers it can.

BOSTON » 2/23/2009 » Citrix Systems, Inc. (Nasdaq: CTXS), the global leader in application delivery infrastructure, today unveiled a groundbreaking new version of Citrix® XenServer™ – the company’s enterprise-class, cloud-proven virtualization platform – that will be offered free of charge to any user for unlimited production deployment.  While basic hypervisors have been free for years, most have had limited practical use in real world environments.  With this new release, XenServer sets an entirely new standard for free virtualization with the addition of powerful new features like centralized multi-node management, multi-server resource sharing and full live motion.  Dramatically lowering the entry price of virtualization also helps address today’s challenging economic climate by making enterprise-class virtualization far more accessible to businesses of all sizes, regardless of budget.

Xen Enterprise is running in 5000 datacenters worldwide. Downloads will be available in March. Here's the official announcement.

Scenario: In the Dom0 (Host) you have a file that you export to the DomU (Guest) and it appears as an entire hard drive and you want to make it larger.

Example- Dom0: /srv/xen/diskimage.img -> DomU: /dev/xvda

If you're using diskimages for your DomU drives you may need to increase their size if any of the DomU partitions become full.

Resize the Xen Diskimage in Dom0

1. Create a backup of the diskimage from Dom0

2. Shutdown the DomU

3. Add extra space to the diskimage using dd. This will add 1GB to the DomU image. Adjust count=  depending on how much you want to add. If you want a sparse file use seek= to define the entire disk size.

dd if=/dev/zero bs=1M count=1024  >> ./diskimage.img

or if you want a sparse file

dd if=/dev/zero bs=1 count=0 seek=1G  >> ./diskimage.img

4. Boot the domU

Your disk should now be larger. You will need to use traditional tools inside the DomU to make the partitions and filesystems larger.

Following are examples for Partitions and LVM.

Expanding DomU Partitions from within DomU

In this example we're using /dev/xvda as the example DomU device name, change this depending on your setup. Note this tutorial only works for resizing the last partition on the diskimage drive.

1. Start the DomU and log in as root

2. Start fdisk /dev/xvda

3. Delete the last partition and recreate it with the start cylinder being identical as before and the ending cylinder being the default (end of disk)

4. Exit fdisk

5. You may have to reboot the DomU before going on.

5. Resize the filesystem on the partition - resize2fs /dev/xvda1

That's really it! You can only hot resize if the Filesystem is getting larger. If you need to shrink it then you'll have to take the Volume offline first. Isn't this easier than dealing with partitions that are too small?

If the partition you want to resize is in the middle of the DomU drive you're in a bit of a pickle. For example if you want to resize / you have problems.

• /boot - /dev/xvda1
• / - /dev/xvda2
• /var - /dev/xvda3

This is the primary reason to using LVM. The solution to this problem isn't very elegant. You basically need to make another disk image and attatch it to the DomU in exactly the same manner as you attached /dev/xvda. The new drive should appear as /dev/xvdb if that's the way we entered it in the DomU config. Once it's done you need to restart DomU, fdisk and format the drive. Once formatted you can mount it and copy all of /var over, change /etc/fstab to map /var to /dev/xvdb1 and reboot the DomU again. Once rebooted you can delete /dev/xvda3 and resize /dev/xvda2.

This process is really no different than if you had a real server but you don't have to install a physical hard drive. I think this shows why LVM is such an improvement over physical partitions.

Scenario: In the Dom0 (Host) you have a file that you export to the DomU (Guest) and it appears as a hard drive partition and you want to make it larger.

Example- Dom0: /srv/xen/diskimage.img -> DomU: /dev/xvda1

Resize the Disk Image in Dom0

1. Shutdown the DomU

2. Create a backup of the Disk Image using the cp command

3. Add extra space to the diskimage using dd. This will add 1GB to the DomU image. Adjust count= depending on how much you want to add. If you want a sparse file use seek= to define the entire disk size.

dd if=/dev/zero bs=1M count=1024 >> ./diskimage.img

or if you want a sparse file

dd if=/dev/zero bs=1 count=0 seek=1G >> diskimage.img

4. Boot the domU

Your view /proc/partitions your disk should now be larger. You will need to use traditional tools inside the DomU to make the partitions/LVs and filesystems larger as outlined below.

Expanding DomU Partitions

In this example we're using /dev/xvda as the drive name inside the DomU. Due to limitations in the way traditional partitions work this tutorial is only useful for resizing the last partition on the DomU drive.

1. Start the DomU and log in as root

2. Run fdisk /dev/xvda

3. Note the last partitions start cylinder, then delete the last partition and recreate it with the start cylinder being the same as before and the end cylinder being the default (end of disk)

4. Save this and exit fdisk

5. Run partprobe to update the kernels partition table. View /proc/partitions to see if the last partition is now larger. If not, reboot.

5. Resize the filesystem on the partition, for example using xvda2: resize2fs /dev/xvda2

Expanding DomU Logical Volumes

If you configured your DomU to use LVM and your Logical Volume is not big enough you can resize it.

In the DomU we get the Logical Volume name by using the lvdisplay command.

[ root@vs /srv/xen ] lvdisplay
--- Logical volume ---
LV Name                /dev/vgsys/lvvirt
VG Name                vgsys
LV UUID                XMWzWW-oZih-A5uH-91Sa-7l1y-8cqf-18KcNB
LV Write Access        read/write
LV Status              available
# open                 1
LV Size                60.00 GB
Current LE             1920
Segments               2
Allocation             inherit
Read ahead sectors     auto
- currently set to     256
Block device           253:2

According to lvdisplay the path to our Logical Volume is /dev/vgsys/lvvirt.

Hot Resizing Logical Volume:

Resizing the Logical Volume is actually very easy, you'll be amazed.

lvresize --size +10G /dev/vgsys/lvvirt

This lvresize command specifies to add 10GB to /dev/vgsys/lvvirt. This will only take a second.

Hot Resizing the filesystem:

resize2fs /dev/mapper/vgsys-lvvirt

That's really it! You can only hot resize if the Filesystem is getting larger. If you need to shrink it then you'll have to take the Volume offline first. Isn't this easier than dealing with partitions that are too small?

I have been a long time user of the Nokia Mobile Internet Devices (MID) and but have always had a few complaints with them. I wish my n800 was smaller, faster, more stable and had better internet range. The OS and applications are getting more stable with time but I can't do anything about the speed factor. The n810 wimax would have taken care of the the size and range issues. That is if Nokia hadn't discontinued it.

According to Nokia the U.S. rollout of Wimax is taking longer than expected. My first thought is to sell it anyway because it's barely more expensive than the n800 but I can also see there point. They sell a device that can access internet anywhere in a city but it only works in 6 cities. Wimax is coming to Seattle in March I believe through Clearwire so I was waiting until then to buy it. If it takes another year to roll out Wimax in all major U.S. cities then Nokia could have another device out by then. Rumor has it that the next Nokia MID will have a 3g cell connection. At that point I hope Nokia finally invests some time into the OS because it's not up to iphone, Palm Pre or Google's Android phone OS. It's not a "Linux isn't good enough" thing because the last two in the list I mentioned are Linux, the first is Unix based. Who would have thought the 50 year old server Operating System would dominate the Smart Phone world?

So I guess I hang out and keep using the n800 until I know more. Or God forbid start looking into a smart phone. I will NOT go down the iphone route because I don't want anyone telling me that I can't install something on a device I bought nor do I think using one application at a time is adequate. I'd like a Palm Pre but after using a 4.13" screen I'm not sure I could browse the web on a 3.1" screen. Maybe in the coming months more Android phones will come out. I'll wait.

This isn't really a howto per se but rather a pointer to RPMs for KVM on CentOS/RHEL.

You can get KVM 80 for x86_64 here.

http://www.lfarkas.org/linux/packages/centos/5/x86_64/

The same site doesn't seem to have i386 RPMs but they do have i386 SRPMS that you could build.

http://www.lfarkas.org/linux/packages/centos/5/SRPMS/

I don't have time to do any sort of tutorial on building KVM SRPMs because I'm not currently using KVM for any projects. In the future I'll get to it but probably not too soon.

Download xen-tools, install rpmstrap and install xen-tools. If there's a newever version of xen-tools available substitute that filename

yum install -y rpmstrap 
wget http://xen-tools.org/software/xen-tools/xen-tools-3.9.tar.gz
tar -xzvpf xen-tools-3.9.tar.gz
cd xen-tools-3.9/
make install

I've not using xen-tools that much but I wanted to put together a tutorial anyway. Let me know how it goes.

Copy and paste the following command blocks depending on your cpu architecture.

For x86_64

wget http://downloads.sourceforge.net/enomalism/enomalism.public 
wget http://downloads.sourceforge.net/enomalism/enomalism001.pubkey.asc
rpm --import enomalism.public
rpm --import enomalism001.pubkey.asc
wget http://downloads.sourceforge.net/enomalism/libvirt-0.4.1-1.CentOS5.x86_64.rpm?modtime=1205833130&big_mirror=0
yum install /libvirt-0.4.1-1.CentOS5.x86_64.rpm
wget http://downloads.sourceforge.net/enomalism/Enomalism2-2.1-py24-noarch.rpm?modtime=1223313658&big_mirror=0
yum install Enomalism2-2.1-py24-noarch.rpm
/etc/init.d/mysqld start
chkconfig mysqld on

For x86_32

wget http://downloads.sourceforge.net/enomalism/enomalism.public 
wget http://downloads.sourceforge.net/enomalism/enomalism001.pubkey.asc
rpm --import enomalism.public
rpm --import enomalism001.pubkey.asc
wget http://downloads.sourceforge.net/enomalism/libvirt-0.4.1-1.CentOS5.i386.rpm?modtime=1205833113&big_mirror=0
yum install libvirt-0.4.1-1.CentOS5.i386.rpm
wget http://downloads.sourceforge.net/enomalism/Enomalism2-2.1-py24-noarch.rpm?modtime=1223313658&big_mirror=0
yum install Enomalism2-2.1-py24-noarch.rpm
/etc/init.d/mysqld start
chkconfig mysqld on

Set a mysql root password if you don't already have one. Substitute your password for .

   mysqladmin password  

Configure Enomalism. Substitute your mysql_root_password, your desired_enomalism_username and desired_enomalism_password.

cd /opt/enomalism2
scripts/init-db.sh mysql_root_password desired_enomalism_username desirec_enomalism_password
  
cp default.cfg config/$HOSTNAME.cfg
uuidgen
#Copy the output from uuidgen to the clipboard

vi config/$HOSTNAME.cfg

• Change sqlobject.dburi="mysql://enomalism2:zx45qw12@localhost/enomalism2" to reflect your proper MySQL username and password.
• Change enomalism2.self="5fe6f05e-7ee0-11dc-ba7c-0011d88b8e81" paste the output of uuidgen here
  
• Change enomalism2.baseurl="http://127.0.0.1:8080/rest/" to the IP/hostname you use to access the Enomalism web interface.
• Change enomalism2.ip_addr="1.2.3.4" to the IP/hostname you use to access the Enomalism web interface, this will be used later for clustering.

Configuring VNC access to your VMs

• /etc/libvirt/qemu.conf (NOTE: If this file is missing or is a directory, you probably did not install the 0.4.1 version of libvirt!)

  # VNC is configured to listen on 127.0.0.1 by default.
  # To make it listen on all public interfaces, uncomment
  # this next option.
  #
  # NB, strong recommendation to enable TLS + x509 certificate
  # verification when allowing public access
  #
  vnc_listen = "0.0.0.0"
  

• /etc/xen/xend-config.sxp

  # The interface for VNC servers to listen on. Defaults
  # to 127.0.0.1  To restore old 'listen everywhere' behaviour
  # set this to 0.0.0.0
  (vnc-listen '0.0.0.0')
  

Running Enomalism

service enomalism2.sh start

• If no errors occur point your browser to: http://server:8080 , where "server" is the IP or the hostname of the enomalism server.
• After the install completes, click on the bottom link and log in using
  • username: admin
  • password: password

I was watching Tekzilla today on Miro (Oooh Veronica Belmont, if she won the elections she'd be Baberiham Lincoln - shwing) and they mentioned the Invisible Shield from Zagg for the ipod. As a brutally active user of the Nokia n800 I need a new screen protector because it's getting hard to see through my old one because of all the scratches. I went to the Zagg site and they do indeed have a screen protector for the n800 and it's priced at $12.95 so I have one on the way. You can check out the Invisible Shield Video to see how tough it is. According to the video you can attach your ipod (with Invisible Shield) to the leading edge of a helicopter blade and it won't get damaged. Perhaps that's not what they said but it's supposed to be tough. As soon as I get mine I'm going to beat up on it and we'll see how tough it is. Also I use a silicon case for the n800 which adds bulk but makes it easier to hold on to. If I could find a way to make it less slippery I'd get rid of that too.

Zagg has way more invisible shields that I would have ever thought. Here's the URL for the Nokia n800 version.

It will take you about 5 minutes to run out of space on the internal 256 MB of flash provided on the Nokia n800 so moving your Operating System to a flash card is a good idea. It's our goal is to install the latest Diablo firmware, install the bootmenu and then move the OS to flash.

Install Diablo firmware

1. Download the flasher for Linux and tablet model from Nokia's Tablet Dev site
2. In the same directory download the latest firmware image
   • for N810
   • for N800
3. Make sure the battery of your tablet is fully charged.
4. Unplug charger and switch off the tablet.
5. Connect the tablet to your computer via USB without turning it on.

Execute as root and replace with the firmware image you downloaded from Nokia:

For the N800 and N810:

./flasher-3.0 -F RX-34_DIABLO_5.2008.43-7_PR_COMBINED_MR0_ARM.bin -f -R

You should now see Suitable USB device not found, waiting, switch on your tablet while holding the Home-button (N800) or swap button (N810), and watch the messages on your console as the FIASCO image is flashed, after which it will reboot automatically—you're done!

Now we need to install a couple of files to get us our boot menu and then to move the OS to flash.

Move Diablo to flash and install boot menu

Before we get too carried away adding buggy software to Diablo (you know you will) we'll move it to flash and we can add the buggy software. This way when it stops working and we need to fix it but don't have time we can just reboot in the stock Diablo firmware.

This tutorial will delete all information on your SD memory card! Install only one SD card into the system, if there are two it won't work.

1. Using the web browser on the Tablet browse to http://penguinbait.com/
2. Click on Install Tools and select Save Target As.. and save it to Documents
3. Open Application Manager, Select Install from File menu and select the Install Tools file
4. After it's done installing the reboot and choose Boot from Flash from the boot menu

There are a lot of problems with the new VirtualBox 2 series. I've found many things don't work as they're supposed, I get lockups for no reason and the new features just don't warrent a full version increase. I've rolled back all my projects at work to VirtualBox 1.6.6 and decided in non-mission critical situations (home use) I'd continue using VirtualBox 2.02 and just deal with the bugs. Well, I'm officially back-pedaling on that now. VBox 2 is buggy as heck and I'm not going to continue using it.

In order to downgrade your VMs from 2.x to 1.6.6 you'll need to edit a few xml files. If you had 1.x installed and upgraded to 2.x then it will have molested your xml files so you'll need to edit them. For each VM there is an xml file in the Machines directory containing the configuration data.

/home/grant/.VirtualBox/Machines/Linux Mint/Linux Mint.xml

 <HardwareVirtExNestedPaging enabled="false"/>

  <GuestProperties>

        <GuestProperty name="/VirtualBox/GuestAdd/Vbgl/Video/SavedMode" value="1280x960x32" timestamp="1224693483507107000" flags=""/>

</GuestProperties>