Total Pageviews

Tuesday, August 30, 2011

specvirt + my hypervisor is better than yours

I've seen a number of presentations recently where companies are putting up SPECvirt data and drawing some interesting conclusions.   I am not a SPECvirt expert but it seems to me that they're not comparing / contrasting the data properly.    Here's an example.

Note:  There is absolutely nothing wrong with this image.  The interpretation by some people is what appears to be wrong.  I've heard a number of speakers (who are *not* associated with redhat by the way) implying that the data shows KVM being substantially better than vmware esx.

Note:  the above is just an example of the type of metrics i've seen, this is not the actual chart in question - it was just one I found to be handy  :-)

So what am I saying here?  From what I understand the above chart is simply a chart of specvirt numbers.  It cannot be used as a comparison between esx and kvm as the underlying hardware is different.

If we look at the specvirt results themselves then there are only a couple of comparisons between KVM and ESX on the same hardware.   Look for
Hewlett Packard Company ProLiant DL580 G7

RHEL 6.1 (KVM) 3802@234
VMWARE ESX 4.1 3723@228

These numbers are pretty close and I haven't seen enough data to understand if the difference between the two is in the noise for the benchmark

I think we can safely say that the performance is probably the same, maybe an edge to KVM.   I think we're likely to see bigger differences within platforms when say for example in KVM you use vhost_net drivers, remove non-required h/w from the guests, huge pages, pci pass-through etc etc to optimize the platform performance - that could easily lead to a 10% performance change.

SPECvirt is really good and is a fantastic tool for determining relative performance impacts of tuning actions within a h/w platform.   Please don't abuse the numbers.

If i'm wrong, please tell me and hopefully tell me why  :-)

Sunday, August 28, 2011

Oracle VM 3.0 hits the streets

It seems many of the hypervisor vendors are displaying their wares at the moment.   Oracle VM 3.0 is out now with some greatly appreciated additional functionality.   Of course anyone who has used certain oracle products on oracle vm will be wondering how you manage pinned cpus in this new environment - more to come i'm sure.

New features include:
  • Distributed Resource Scheduling for capacity management, providing real time monitoring enabling rebalancing of a server pool.
  • Distributed Power Management for reduction of powered-on servers.
  • Centralized network configuration and management, using Oracle VM Manager
  • Server and storage discovery.
  • Xen 4.0 hypervisor
  • Updated Dom0 command and control kernel
  • Supporting up to 160 CPUs and 2 TB memory for physical servers
  • Supporting up to 128 vCPUs for Virtual Machines
  • OCFS2 1.8 cluster file system
  • Support for Open Virtualization Format (OVF) Virtual Machine file format.
  • Browser based Oracle VM Manager GUI
  • Job management framework
  • Extensive event logging
  • Performance statistics for CPU,memory, disk and network for physical server and VMs

Saturday, August 27, 2011

RHEV 3.0 - it's in BETA and almost here!

Yes, that's right.  RHEV 3 is almost here.  It's currently in BETA.   Unfortunately, i've not yet been able to try it out directly, but i've done quite a bit of research into the underlying architecture and have been working with some of the upstream components for a little while now.

The press release reads as follows :


Today’s Beta of Red Hat Enterprise Virtualization 3.0 previews several key enhancements, including:
  • Red Hat Enterprise Virtualization Manager is now a Java application running on JBoss Enterprise Application Platform on Red Hat Enterprise Linux
  • An updated KVM hypervisor based on the latest Red Hat Enterprise Linux 6
  • Industry-leading performance and scalability levels, supporting up to 128 logical CPUs and 2TB memory for hosts, and up to 64 vCPUs and 2TB memory for guests
  • A power user portal that allows end users to provision virtual machines, define templates and administer their own environments
  • A RESTful API that allows all aspects of Red Hat Enterprise Virtualization to be managed and configured programmatically
  • New multi-level administrative capabilities, improving product functionality for very large deployments
  • New local storage capabilities
  • An integrated and embedded reporting engine allowing for analysis of historic usage trends and utilization reports
  • SPICE WAN optimization and enhanced performance including dynamic compression and automatic tuning of desktop effects and color depth.  The new version of SPICE also features enhanced support for Linux desktops.


It'll be interesting to see how it stacks up against the market leader - vSphere,  performance-wise the hypervisors are definitely on-par, with KVM actually performing a little better according to the specvirt benchmarks.

The 'secret sauce' in this market is the management tools and it's clear there has been some significant effort in this area with the RHEV-M re-platforming.  Hopefully this energy can be re-directed post conversion to increasing the functionality.

There are still some operational quirks in this release, though the installation now on rhel6 looks quite simple (yum install rhevm).  Unfortunately,  you still need a windows client running internet explorer to use the web gui.  I'm led to believe that this requirement for WPF finally disappears with 3.1 as it is replaced with a GWT functional equivalent.