virt June 2011

virt@lists.centos.org

26 participants
12 discussions

Drupal/MySQL performance in Xen and OpenVZ
by Einar S. Idsø 08 Jun '11

08 Jun '11

Hi, We are considering a transition from OpenVZ to Xen for our web server infrastructure. The primary task performed by the virtual servers is to run a number of Drupal sites with a MySQL backend. The webserver and MySQL servers are on separate virtual hosts. We also have a number of smaller hosts running on the same hardware (a couple of dev-servers, a logging-and-monitoring server, a secondary webserver ++). >From what I have understood, there is very little performance degradation in OpenVZ, also for IO operations, due to the use of isolated containers instead of actual virtualisation. I have also seen tests indicating detrimental IO performance of Xen IO [1]. Despite this, I have found several posters [2] suggesting the use of Xen over OpenVZ when it comes to running Drupal sites. One of the main arguments against OpenVZ is unpredictable and variable performance because VPS-hosts tend to overbook their host capacitiy. This is not an issue for us since we host our own VPSs on our own hardware so we are in complete control. So: Is there any reason Xen may be able to outperform OpenVZ for the webserver-setup I have described, or should I just continue to use OpenVZ? Cheers, Einar Sources: [1] http://www.ilsistemista.net/index.php/virtualization/1-virtual-machines-per… [2] http://2bits.com/articles/hosting-virtualization-openvz-vs-xen-which-is-bes…

2 3

Confused by "qemu-img convert"
by MargoAndTodd 07 Jun '11

07 Jun '11

> Hi All, > > Okay. Now I am confused. > > I have a bunch of virtual machines running under Virtual Box 3.2.12. > I want to run them under KVM and drop Virtual Box from these > systems. > > Supposedly "qemu-img convert" now supports direct conversion > from vdi to whatever KVM uses. So I fired up the man page and > got really confused. Then I fired up Google and got worse > confused. > > Might I impose on some kind individual to write down a sample > run string that would show me how to do this? > > Many thanks, > -T > Is it as easy as? qemu-img convert -f vdi oldImage.vdi -O qcow2 newImage.qcow Do I need a ton of disk space to go to a full hard drive then back to a small virtual hard drive? Do I need the Virtual Box XML file for anything or just the VDI? Many thanks, -T

2 3

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

virt June 2011