LVM’s snapshot feature enables us to duplicate an LVM backed Xen DomU in seconds rather than minutes. We no longer need to copy the entire file system image like backing up file backed Xen DomU. We just need to make a snapshot of the current Xen DomU in seconds. When there are changes to the…
The Xen hypervisor is a powerful virtualization solution that provides virtualization capabilities for x86, x86-64, and ARM architectures. The source code structure of Xen is organized into several directories, each of which contains a specific set of files. The backend and frontend drivers are an important part of the Xen hypervisor, and they provide a…
This posts list benchmark (using bonnie++) result of I/O performance of Xen LVM and loopback backed VBDs. The configuration of machines Dom0 VCPU: 2 (Intel(R) Xeon(R) CPU E5520 @ 2.27GHz) Memory: 2GB Xen and Linux kernel: Xen 3.4.3 with Xenified 2.6.32.13 kernel DomU VCPU: 2 Memory: 2GB Linux kernel: Fedora (2.6.32.19-163.fc12.x86_64) DomU’s profile: name=”10.0.1.200″ vcps=2…
This is the latest stable and recommended stable Xen Dom0 solution on Fedora 12. No serious bug found till now and we will fix the bugs by ourselves if some appears. It also works on Fedora 14 as well. It should not be hard to use this solution on other versions of Fedora or other…
Here is a list of problem that may occur during installing and configuring Xen Dom0 in Fedora. It is found originally in Fedora systems, but the tips in this post should also be helpful for installing Xen Dom0 on other platforms. BIOS configuration If xen stops at: “I/O virtualization disabled.” We may need to enable…
The Xen solutions including installing and configuring Dom0 and DomU are summarized here. LVM volumes as backing for DomU’s file system is an appealing solution to Xen VBD. LVM volumes can dynamically grow/shrink and snapshot. These features make it simple and fast to duplicate DomU and adding storage to DomU. LVM backed DomU is recommended….
Creating file-backed virtual block device (VBD) for Xen virtual machines and installing Fedora 12 in Xen DomU via internet will be introduced. Note that this tutorial is based on a pretty old OS (Fedora 12). But the method here is still valid while some minor details may need to be changed for latest Xen and…
How to jailbreak Apple iPod touch in Linux will be introduced in this article. We use Spirit to jailbreak iPod touch. Spirit[1] is an untethered jailbreak for iPad, iPhone, and iPod touch on certain firmware versions. Please read [1] for requirement when using Spirit. Currently, the version of iTunes used should be iTune 9 earlier…
tmpfs has blazing speed. Why not set up a high speed NFS server on top of tmpfs? A little trick is required for setting NFS server on top of /dev/shm. If we add a normal entry in /etc/export and them run # exportfs -a exportfs will give us a warning like this: exportfs: Warning: /dev/shm…
Firefox can be much faster on Linux! Let’s speed up Firefox on Linux system. Part 1 and 2 only config firefox, so it can also be used on other platform such as Windows. 1. Pipe-lining network connection Most of us use a broad band width network, then why not pip line the connection from Firefox?…
Please refer to for the latest stable Xen Dom0 solution. In this post, the detailed tutorial for setting up Xen 3.4.1 dom0 on top of Fedora 12 with kernel 2.6.29 will be introduced. Hardware: Dom0 hardware platform: Motherboard: INTEL S5500BC S5500 Quad Core Xeon Server Board CPU: 2 x Intel Quad Core Xeon E5520 2.26G…
Automatic passwrod-less ssh login can make our life easier. To enable this, we have 2 options: using key-based authentication by copying our SSH public keys to the remote machines for automatic password-less login or using password-based authentication. I will introduce the 2 options in the post. Before you start, please note that key-based authentication is…
Sharing the networking is important and setting up a gateway is a good solution to it. Building up the gateway on a Linux box is easy, cost efficient and reliable. With a Linux box, you can share the internet connection or the only cable connected to the network. The Linux box network configuration The Linux…
Previously, we create a configuration file for each DomU virtual machines in our cluster. Most of the content in these configuration files is the same. The differences are only the name, memory size and image file address. There are several disadvantages of this method: We must create and configure a new configuration file when creating…
A script for backing up file-backed Xen DomU is introduced in this post. This script can be changed to similar platform. In our cluster, virtual machines are stored under /lhome/xen/. Virtual machine with id vmid is stored in directory vmvmid. The raw image disk file name can also be derived from vmid. Some more details…
I have done some I/O performance benchmark test of Xen DomU. For easier management, some of our DomU VMs are using file-backed VBDs. Previously, our VMs are using Loopback-mounted file-backed VBDs. But blktap-based support are recommended by Xen community. Before considering changing from loopback based VBD to blktap based VBD, I have done this performance…
Assumption: There are VBD based Xen DomU virtual machines stored under /home/xen/vm-f11-sample/. There are two files under vm-f11-sample: vm0-f11.run (The configuration file) and vmdisk0 (The virtual disk). Now we want to duplicate the virtual machine vm0 stored under vm-f11-sample to vm-10.0.0.213 which is stored under vm-10.0.0.213. And vm-10.0.0.213’s ip will be 10.0.0.213. The steps to…
Please refer to Setting Up Xen Dom0 on Fedora : Xen 3.4.1 with Linux Kernel 2.6.29 on Fedora 12 for the platform of this test (this test runs on Fedora 11, however). I have done some simple performance test on DomU and Dom0 and compare with the performance on physical machines. These test are simple,…
I find a desktop client for publishing to WordPress blogs – lekhonee[1]. I find it interesting and easy to use. This is the first post using it. The interface is simple, but it can provides most of the functions: * Writing post. * Select categories. * Add tags. * Load and Edit the old post….
I usually keep Thunderbird open when my computer is open. But Thunderbird is minimized to the taskbar. It will be more convenient if it is minimized or closed to the system tray as an icon.It will be better if it can display the number of unread messages. Mozilla’s software’s addon system give the method to…