With GigaTux's HVM offerings (mainly Windows but some BSD in there as well) we very strongly recommend users install paravirtualised network and disk drivers. In Windows, this is offered by the GPL PV installer. However, we didn't really know that there was more of a spectrum between PV and full virtualisation and this article by George Dunlap details how this works in a comprehensive manner. It's fascinating to hear that even what we consider standard paravirtualised Linux instances could be making use of some HVM functionality to negate the need for a PV MMU, and we look forward to this transparent speed boost in the near future!

What if we could run a fully PV guest -- one that had no emulated motherboard, BIOS, or anything like that -- but used the HVM extensions to make the PV MMU unnecessary, as well as to speed up system calls in 64-bit mode?

This is exactly what Mukesh's PVH mode is. It's a fully PV kernel mode, running with paravirtualized disk and network, paravirtualized interrupts and timers, no emulated devices of any kind (and thus no qemu), no BIOS or legacy boot -- but instead of requiring PV MMU, it uses the HVM hardware extensions to virtualize the pagetables, as well as system calls and other privileged operations. We fully expect PVH to have the best characteristics of all the modes -- a simple, fast, secure interface, low memory overhead, while taking full advantage of the hardware.

Sophos have written up a nice, comprehensive overview of IPv6 and why we need to all switch to it from a security perspective. Do take a read and always consider whether your hosting provider supports IPv6 before making any moves. GigaTux supports it natively in the US and Germany and is less than 1ms from the nearest IPv6 tunnel in the UK.

IPv6, has the features and solutions the modern Internet requires that IPv4 can’t provide: greater connection integrity and security as well as the ability to support the vast number of web-capable devices we’ll need for a long time to come. But even as IPv6 brings some security enhancements, its significant changes could also introduce security holes into your environment. So why would anyone want to adopt IPv6 if it could be troublesome?

KVM has, quite rightly, been getting a lot of press since its full functionality was introduced in to the mainline kernel earlier this year. However, some communities have assumed this has sounded the death knell for Xen. This article at the Xen blog offers some insights into the differences and similarities between Xen and KVM, and how they do not set out to achieve the same goals.

KVM is a type-2 hypervisor built into the Linux kernel as a module and will ship with any Linux distribution moving forward as no work is required for the Linux distributions to add KVM. Having a virtualization platform built-in to the Linux kernel will be valuable to many customers looking for virtualization within a Linux based infrastructure; however these customers will lose the flexibility to run a bare-metal hypervisor, configure the hypervisor independent of the host operating system, and provide machine level security as a guest can bring down the operating system on KVM.

Xen, on the other hand is a type-1 hypervisor built independent of any operating system and is a complete separate layer from the operating system and hardware and is seen by the community and customers as an Infrastructure Virtualization Platform to build their solutions upon. In fact, the Xen.org community is not in the business of building a complete solution, but rather a platform for companies and users to leverage for their virtualization and cloud solutions. In fact, the Xen hypervisor is found in many unique solutions today from standard server virtualization to cloud providers to grid computing platforms to networking devices, etc.

We're actively trialling Xen 4.0 and continue to be very impressed with this, especially liking blkback2. We're also looking forward to shared memory pages.

GigaTux will keep on using Xen for now, but are keeping an eye on KVM particularly. We are intending on only considering open source virtualisation solutions, so VMWare is out of the picture for us, but the article above certainly shows that competition is present, and competition is generally a good thing!

What we found is that the large majority of customers (71 per cent) haven’t settled on a single x86 virtualization solution. Although 82 per cent of our survey respondents said that they are using VMware on at least some of their systems, we found that Xen variants from Citrix, Sun/Oracle, and Xen.org were being used by more than half of the customers we surveyed. Another 31 per cent of customers said that they use KVM.

The guys at Turnkey Linux have just released a new set of appliances, along with updates to their existing ones. They've added a whopping 25 new appliances, all of which we will have available shortly at GigaTux for install on our VPS systems.

They've clearly been very hard at work creating these, so hats off to them!

GigaTux will provide a donation for any users choosing Turnkey Linux on their VPS. We haven't decided yet the structure of the donations, but their good work will definitely be rewarded!

I'm proud to announce the 2009.10 release batch featuring:

• 25 new additions to the TurnKey Linux virtual appliance library
• added native virtual appliance packaging (OVF support included)
• Amazon EC2 support, with EBS persistence
• Core improvements: Ajax web shell, upgraded to Ubuntu 8.04.3

The project recently celebrated its one year birthday. Since our last major release in March the project picked up steam with weekly downloads increasing over 500% (we just flew past 60,000 downloads). Not bad for a new server oriented project. With all the goodies in this new release, and all the stuff we're working on for the next release, TurnKey Linux's second year should be even more interesting.

This release is a big one. Previously we tried "releasing early releasing often", but discovered we could get more done by batching certain phases of virtual appliance development and decided to give bigger release increments a try.

Your choice of underlying virtualisation technology really matters.

Headlines from other VPS providers offering hundreds of megabytes of burst memory, along with simply fitting more VMs onto a physical server, do make it difficult to compete on raw figures for the price. However, those looking to buy a VPS really need to look at the technology they will be running on.

I'm happy to have found an excellent article describing the details between Xen (which we use) and Virtuozzo (which many competitors use). Read and be enlightened!

We currently use Xen as our virtualization technology. To put it simply, Virtuozzo (or the open source version OpenVZ) is one level above chrooting or BSD jail. Yes, Virtuozzo has much less overhead per VPS instance and has some performance advantages, but at a cost of isolation and reliability. Virtuozzo uses OS level virtualization, while Xen uses paravirtualization.

When evaluating the different virtualization technologies we had very specific requirements. We wanted virtualization technology that allowed for:

• dedicated server like isolation.
• customizations to the installed operating system (i.e. kernel, iptables, etc.) just like a dedicated server.
• proven deployment.
• cannot oversell services (ensuring a specific level of quality of service).
• complete separation of each operating system installation.

The differences with Virtuozzo and Xen are:

• fixed memory and disk definitions.
• custom kernels.
• firewall configuration.
• isolation.

For our purposes Xen acts, breaths, and looks like a dedicated server.

Oh dear - why do large companies, such as Microsoft, have to wait for the exploit to be demonstrated before doing something about poor code. Things like this are serious and undermine everything about about HTTPS/SSL. Poor effort from the certificate supplier too for allowing the null character.

[A] hacker on Monday published a counterfeit secure sockets layer certificate that exploits a gaping hole in a Microsoft library used by all three [MSIE, Safari, Chrome] of those browsers. Although the certificate is fraudulent, it appears to all three to be a completely legitimate credential vouching for the online payment service. The bug was disclosed more than nine weeks ago, but Microsoft has yet to fix it.

Google Wave: You need to pay attention to this.

So here's the deal with Wave: If you deal in technology, and you get this one wrong, you'll miss the boat. And it's a big boat. If, on the other hand, you get this one right, you have the potential to do some incredible innovation.

In a nutshell, this is the next revolutionary leap in Internet application architecture. Maybe the first truly revolutionary leap since HTTP itself.