Xen is a hypervisor based virtualization. It supports x86, AMD64, IA64, ARM and other CPU types, and Linux, Windows, Solaris and *BSD guest operating systems.

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Xen DomU on DRBD device: barrier errors

I'm testing setting up a Xen DomU with a DRBD storage for easy failover. Most of the time, immediatly after booting the DomU, I get an IO error: [ 3.153370] EXT3-fs (xvda2): using internal journal ...
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My VPS crashed and I have no idea why

I have a VPS with Linode right now. I was alerted by my monitoring service that a site I was hosting had gone down. I used Lish, Linode's method of getting direct out-of-band access to the console ...
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1answer
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EC2 issue using PV-Grub and custom kernel: error 21 selected disk does not exist

Over on EC2 I am trying to setup AMI's for PLD-Linux that use the new features that allow running custom kernels from inside the AMI using PV-Grub. I've setup custom AMI's many times before but can't ...
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343 views

How can I generate filesystem images that are usable on many different virtualization systems?

I have written a script that generates a root filesystem image (based on Debian lenny) suitable for User-Mode Linux. (Essentially this script creates a filesystem image, mounts it with a loop device, ...
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How can I know when a Xen VM has started when starting using CLI

I'm using XenServer as a host for disposable QA machines for our application development. I'd like to write a script that automatically creates a new VM from a template, starts it, logs into it, ...
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Running SQL 2008 on a VM

We are pondering trying to set up a SQL 2008 instance inside a VM for a production environment. All our SQL instances use iSCSI over gigabit ethernet to talk to a NAS, as would this new instance. ...
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418 views

Using more recent kernel for Xen Dom0 in production

Does anyone have experience running Xen dom0 on a more recent kernel than the stock 2.6.18? What host distro are you running? What release of Xen (or hg/git changeset)? What set of patches are you ...
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Can I automate XEN? And to what extent

I am wondering about a certain scenario. User on some machine runs a command. This unpacks XEN and boots up domain 0. Domain 0 boots up 3 other domains that are setup in this way. One is a "client" ...
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Can fragmented MySQL innodb tables cause I/O issues? “task hung for 120 seconds” crashes?

Large innodb databases with load spikes seem to be causing random crashes with "task hung for 120 seconds" in the console. There are no logs being written to the system during these crashes. The ...
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280 views

Hardening Virtual Machine

I have a CentOS based product I'm looking to distribute it as a virtual machine (VMWare, XEN and KVM) and I have been lately assessing the steps needed to protect the VM. The VM's data shouldn't be ...
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257 views

Can i install Xen Hypervisor on a dedicated server that is already in use

I have a dedicated server, currently i sell shared hosting on this server... Now i want to sell VPS also on my server. Is there a way i can sell VPS? Can i use Xen Hypervisor,will it disturb my shared ...
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Intel NIC: VMDc or VMDq?

I need to buy a nic that I want to eventually (~3 months) re-use for a VM server deployment that will need to support heavy network I/O. Server is a Xeon Gulftown/Westmere-EP. Intel has server NICs ...
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cp and cat on Centos 5.5/ext3 is 10x slower for files in certain directories

I was sorting some large files (91GB across 27 files) with GNU sort when I noticed that iostat -dxk 3 showed very slow read speeds, between 5 MB/s and 10 MB/s, with 100% disk utilization. I tried cat ...
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557 views

Please clarify on the relation between Xen, VirtualBox, Sun VM and Oracle VM

Please clarify on the relation between xen, VirtualBox, Sun vm and Oracle vm Which products still exist after Oracle acquired Sun? which of the products that still exists are derived from xen?
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Running KVM/XEN/Hyper-V VMs from a RAM disk, is this possible? Practical?

Currently I'm using ESX (v3 and v4) to test a scripted OS (Windows 2003) and application install DVD. The DVD ISO (8GB) is mounted on a 1Gbps NFS datastore and the VMDK's (20GB) are on an SSD mounted ...
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Stale NFS handle

I have several xen guest OSs that get their root file system from NFS. I changed /etc/network/interfaces on some of them (on the nfs server) and then rebooted them. Now I get lots of 'Stale NFS ...
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548 views

Automatically Port Xen Images to EC2

I have a disk image that is running under Xen right now and I'd like to port it to Amazon's EC2. How can I do this in a way that is as simple as possible? I've got a script that can build the finished ...
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1answer
470 views

Use SSHFS on XenServer 6.1

On Xen Server 6.1, to backup my VMs, I use a script based on the following tools: xe vm-list to build a list of the VMs to backup xe vm-snapshot to take a snapshot of the VMs xe template-param-set ...
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269 views

Can any one clarify this on xen cloud platform/xen server

As per XCP documentation, Xen Cloud Platform host is a 64 bit x86 server-class machine devoted to hosting multiple VMs. on blog.citrix.com they are mentioning about dom0 as It should be noted that ...
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compile kernel 2.6.34 for Ubuntu Lucid for xen dom0 / pvops

I'd like to compile a recent Linux kernel (2.6.34) for my Ubuntu 10.04 Lucid Lynx AMD64 box, mainly because I'd like to use it as a dom0 kernel with the recent xen4. There's plenty documentation on ...
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267 views

Remus on Amazon EC2: If and When?

Slashdot recently brought word that the Remus project (which implements hot-backup Xen instances) has been merged into the core Xen. Since Amazon have leveraged Xen in building out EC2, I naturally ...
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Finding Memory Leak on Linux

I'm going crazy trying to find a memory leak on one of our main boxes. It runs CentOS, kernel 2.6.18, x86-64. The box (actually VM on Xen) has been running great with no problems since it was created ...
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1answer
214 views

Running a Xen Dapper dom0 with a Hardy domU

Is it possible to set up a Hardy domU on an existing Xen dom0 running Dapper? I have found many postings talking about the reverse (Dapper domU on a Hardy dom0), but I have the existing server set up ...
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1answer
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Whole block device named xvda1, xvda2 instead of xvda, xvdb

I am working on a VM that was set up for me in a public cloud. It's running under the Xen hypervisor in paravirtualized mode and has two virtual disks. So I expect the virtual disk block devices to be ...
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556 views

Using ZFS or XFS on a Xen guest running Linux

Background: I'm investigating the viability of using a filesystem other than ext3/4, with the ability to run snapshots for backup and rollback purposes. The servers under consideration are mailbox ...
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1answer
946 views

AppArmor - root: “You do not have enough privilege to read the profile set.”

I'm trying to use AppArmor on a remote hosted Xen server with a custom built kernel. AppArmor appears to be running, but not correctly. For example if I run the following command as root: # ...
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1answer
707 views

Network Bridge in dom0 can not ping domU's

I am using Debian wheezy with XEN 4.1. I have two network bridges xenbr0 and xenbr1. xenbr0 is linked to the real-eth0-nic so the domU's can talk to the outside world, which worked fine. xenbr1 was ...
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1answer
660 views

ruby: invalid opcode

There's a fairly complex application than runs on two VMs (on Xen). Both VMs run CentOS 6.2 with the exact same packages and configuration for every application running (minus networking which is ...
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1answer
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XenServer Converting HVM to Paravirtualised

Recently I have been tasked with the daunting process of converting a setup of HVM enabled VMs (running on Citrix XenServer 5.6.0) into PV (paravirtualised) containers. The constraints of the project ...
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PID ran away with all our MEM and SWAPPED hard - OSSEC RHEL

Forgive me for the length of this question... it is mostly details... only attempt to follow if you also enjoy reading log files... or drinking coffee. I'll state the questions first: 1) how the ...
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271 views

Performance Troubleshooting on a Xen VPS

I have a Xen-based virtual private server, running Ubuntu. It is running Apache, MySQL, and Drupal. Usually, it is nice and fast. However, sometimes it slows down for no apparent reason. How can I ...
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136 views

Xen open source import and export vm

I am using free Xen 4.2.4-30.el6 on centos 6.5 create a vm using virt-install I want to backup and restore virtual machines, but all tutorials talking about citrix and xe command is there any way ...
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1answer
121 views

Smart solution for XenServer firewall?

I've been searching for a smart solution for a XenServer firewall for about a month now. The documentation for the new default networking backend "openvswitch" is not that detailed and I can barely ...
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1answer
812 views

How to get virtualized SR-IOV Infiniband interface UP?

I've spent several days on this now and I've managed to get SR-IOV working with the Mellanox Infiniband card using the latest firmware. The Virtual Functions appear in Dom0 as 06:00.1 Network ...
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1answer
139 views

xend doesn't bring up the vif interfaces

I'm trying working with Xen and I've tryed to build up a virtual machine in domU. I'm using the following configuration for the domU kernel = '/media/home_separata/domU_kernel/boot/vmlinuz-linux' ...
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2answers
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RHEL5.5 yum can't see a package (xen) on repo?

hi i'm trying to install xen via yum on RHEL 5.5. When i browse the repo here: http://ftp.redhat.com/pub/redhat/linux/enterprise/5Server/en/os/SRPMS/ I can see the package i want. specifically ...
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834 views

Xen: Convert image to lvm with minimal downtime

My Goals: Convert all my DomUs from image-based to lvm-based Minimal downtime Minimal performance impact on other DomUs/Dom0 My plan / setup: All my images are in a big lvm-volume, all lvs for ...
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1answer
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Weird nfs performance: 1 thread better than 8, 8 better than 2!

I'm trying to determine the cause of poor nfs performance between two Xen Virtual Machines (client & server) running on the same host. Specifically, the speed at which I can sequentially read a ...
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XenServer for NAS and Virtualization

I'm very new to all this so please go easy on me! I'm wondering whether you can run a NAS and virtualization with XenServer on the one box. Basically, we need virtualization and we've picked ...
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2answers
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Is it possible to a VM inside a VM (e.g., KVM on Vmware)? [duplicate]

Possible Duplicate: Is it possible to setup a virtual machine inside another virtual machine I'd like to do some development on Eucalyptus, an open source project which provides an Amazon ...
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Windows Server 2008 network speed slow, Xen 3.4.3 HVM ISO

I've setup a VM running Windows Server 2008 on a host node running Xen 3.4.3-5 and the following kernel: 2.6.18-308.1.1.el5xen #1 SMP Wed Mar 7 05:38:01 EST 2012 i686 i686 i386 GNU/Linux The network ...
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2answers
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Why do KVM needs Hardware Assisted support to install even Linux based OS

For XEN we dont need Hardware Assisted support for running linux os. But why do we need that for KVM for running even linux based os. Can Kvm be configured to support para virtualization. Edit: ...
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3answers
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clustered file system choice for KVM/XEN in Fibre Channel Environment

Gents, what would you recommend for production use in a FC environment, where live migration is a must? Which clustered file system should we use? OCFS2? Would you still need drbd? Thanks!
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How do I log console output from a XEN VM?

I have a xen hvm vps with a console thats accessible using VNC. I'm wondering if there's any way of logging anything/everything that is sent to console? I'm trying to log the console cause my vps ...
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CentOS or OpenSolaris for Xen dom0?

I would like to play around with Xen with the intention of eventually running a bunch of different services on separate virtual machines (partly just because I can), and have the possibility of trying ...
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2answers
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How to manage Xen virtual machines on shared SAN storage?

We have a small cluster of Xen servers in the office. Each virtual machine system image is on its own block device on our iSCSI SAN. The servers all connect their iSCSI initiator to every VM LUN ...
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Determine which guest is running on XEN: HVM or PV guest

I'm working with a Xen host which is installed XenServer from Citrix by someone. He already installed a lot of CentOS 5.2 guests on the host. I wonder how to check those guests to know they are PV ...
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504 views

demistify virtualization solutions: VDI, client virtualization, server virtualization?

how does VDI, server virtualization, client virtualization; compare - architecture wise? although a lot is written by vendors like Citrix or VMware it is often confusing hidden behind marketing ...
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213 views

DRBD Madness on Virtual Environment (XEN)

Right now I am using DRBD to replicate two directories (/var/www and /var/spool/mail) on two different XEN VPS's and they're 7000 Miles away from each other! on the top of that I am using a ...
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xen - what constitutes a 'system'?

In the release notes for Xen 4.2 this statement appears: Large Systems: Following on from the improvements made in 4.1 Xen now supports even larger systems, with up to 4095 host CPUs and up to ...