• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
Virtualization.com

Virtualization.com

News and insights from the vibrant world of virtualization and cloud computing

  • News
  • Featured
  • Partnerships
  • People
  • Acquisitions
  • Guest Posts
  • Interviews
  • Videos
  • Funding

remus

Updates on Xen

April 16, 2009 by Kris Buytaert Leave a Comment

When you have been in this industry for a couple of years, you might think that the Virtualization industry has stopped innovating, that there are no new awesome features coming out anymore.

Obviously they aren’t coming at the same pace as 5-10 years ago anymore, we aren’t surprised anymore when people add Virtualization support for yet another CPU or publish yet another new and fresh management framework, with a cloud sauce .. But hidden far in the back corner innovation still happens, be it with much smaller and less intrusive steps than before.

So lets have a look at these small changes

First of all a project I’ve been following for a while now .. XenFS , XenFS builds on the idea that you often want to share filesystems between virtual machines on the same physical machine and that you don’t want to use NFS, Cifs or even the regular network stack to achieve this goal.

According to Mark Williamson who’s working on the project :

The major differences from a traditional network filesystem are in the implementation. XenFS is implemented as a XenLinux “split driver”, with kernel modules implementing the client and server portions. Instead of exchanging protocol messages over a network socket, XenFS exchanges requests and responses using shared memory, similar to the “device channels” used by the block and network split drivers. Beyond that, instead of copying data from the server to the client (and back) XenFS also shares the memory containing the actual file data.

XenFS has been around for a while, but KXen is actually brand new. Argumenting over the advantages and disadvantages of a TypeI vs TypeII hypervisor is now over as Xen “supports” both.

Stephen Spector announced the availability of the first public release of Hosted Xen (KXen)

According to Stephen

Xen is the leading open source Type-1 VMM, providing a fast, robust and secure virtualization platform. KXen leverages the Xen technology, extending the range of environments in which the same core engine can be used to existing desktops, laptops and allowing scenarios like run from usb stick.
Work is underway to support MacOSX as the host, as well as 64-bit versions of Windows. The windows 32-bit host code is designed such that it is easy to port to other host operating systems.

The Remus project which we covered earlier , has also released it’s initial Request for Comment code. Remus allows systems to transparently move to another physical machine in the event of a failure on the primary machine , with only seconds of downtime, while preserving the original host state such as active network connections , memory and disk state.
Being an RFC release means that it is meant to start a discussion on how it might be merged with Xen and Kemari. According to the announcement it is not by any means in shape for application to the Xen tree
But it is a giant step forward towards a better high availability solution using Virtualization.

Filed Under: Guest Posts, News Tagged With: kxen, remus, Xen, xenfs

Kemari v1.0 Released

December 6, 2008 by Kris Buytaert Leave a Comment

Last month,TAMURA Yoshiaki from the Kernel Group , OSS Computing Project at the NTT Cyber Space Labs announced the availability of Kemari on the Xen Devel mailing list.

Kemari is an open-source virtual machine synchronization mechanism for fault tolerance. It’s similar to Remus which we covered earlier.

Kemari tries to achieve a fault tolerance setup that does not
require the use of specific hardware or modification of applications.
Kemari aims to keep VMs transparently running in times of hardware
failures. It transfers the state of the primary VM to the secondary
VM when the primary VM is about to send an event to devices such as
storage and networks.
In short it is trying to real time mirroring of Virtual Machine instances.

The, source (Kemari has been released under the GPL) , documentation and different presentations including a Video running both a Linux and Windows demo are available at the Kemari Website

Kemari is listed on Xen Product Roadmap, and is asking for reviews and comments from the community.

We already mentionned Remus in earlier posts here at Virtualization.com and it seems the the Kemari and Remus project are planning to merge in order to to propose a better solution for Xen 3.4 together.

Filed Under: Guest Posts, Videos Tagged With: HA, kemari, open source, opensource, remus, virtualisation, virtualization, Xen

Remus: High Availability via Asynchronous Virtual Machine Replication

April 16, 2008 by Kris Buytaert 3 Comments

The 5th Usenix Symposium on Networked Systems Design and Implementation (NSDI’08) starts today in San Francisco, CA. The NSDI symposium focuses on the design principles of large-scale networks and distributed systems.

XenMaster Ian Pratt (Senior Lecturer, University of Cambridge Computer Laboratory/XenSource (Citrix)) will be presenting the Keynote.
Apart from this Keynote a very interesting paper about Virtualization and High Availability will be presented by the Department of Computer Science at the University of British Columbia.

In a paper titled Remus: High Availability via Asynchronous Virtual Machine Replication Brendan Cully, Geoffrey Lefebvre, Dutch Meyer, Mike Feeley, Norm Hutchinson and Andrew Warfield describe how with minor modifications to Xen 3.1.2
they achieve fast (frequencies as high as forty times per second) replication of Xen virtual machines.

Their tool Remus allows systems to transparently move to another physical machine in the event of a failure on the primary machine , with only seconds of downtime, while preserving the original host state such as active network connections , memory and disk state.

Today most Virtualization vendors claim they achieve High Availability while actually they only implement an easier way to recover from failure or a method to migrate away from a machine that is showing early problems. Most of the current Virtualization based solutions still require you to restart a new virtual machine, or implement High Availability on application level.
‘
Mind , this is a research paper don’t expect these kind of features to show up at your local IT shop within the next couple of weeks.

Thanks to Usenix opening up their conference proceedings for everybod,y you can get the full paper here.

Filed Under: Guest Posts, News Tagged With: Asynchronous Virtual Machine Replication, Brendan Cully, Dutch Meyer, Geoffrey Lefebvre, high availability, Ian Pratt, Mike Feeley, Norm Hutchinson .Andrew Warfield, nsdi08, remus, usenix, Xen

Primary Sidebar

Tags

acquisition application virtualization Cisco citrix Citrix Systems citrix xenserver cloud computing Dell desktop virtualization EMC financing Funding Hewlett Packard HP Hyper-V IBM industry moves intel interview kvm linux microsoft Microsoft Hyper-V Novell oracle Parallels red hat research server virtualization sun sun microsystems VDI video virtual desktop Virtual Iron virtualisation virtualization vmware VMware ESX VMWorld VMWorld 2008 VMWorld Europe 2008 Xen xenserver xensource

Recent Comments

  • C program on Red Hat Launches Virtual Storage Appliance For Amazon Web Services
  • Hamzaoui on $500 Million For XenSource, Where Did All The Money Go?
  • vijay kumar on NComputing Debuts X350
  • Samar on VMware / SpringSource Acquires GemStone Systems
  • Meo on Cisco, Citrix Join Forces To Deliver Rich Media-Enabled Virtual Desktops

Copyright © 2025 · Genesis Sample on Genesis Framework · WordPress · Log in

  • Newsletter
  • Advertise
  • Contact
  • About