Glo Networks Technical Blog (Glo Blog)

In the virtualisation game VMWare are big competitors.  They’ve been selling virtual machine software since 1999 and their products are the ‘go to’ virtualisation tools for many businesses (not us at Glo). But since announcing their most recent price structure changes VMWare have experienced a huge amount of criticism from their customer base.

And we can understand why. The basic gist of the change is a cap on the RAM you can apply to your virtual machines per license. Formally licenses were required on a per processor basis alone, now, if you reach the virtual RAM cap for the number of processor’s you have licensed, you will require extra licenses to cover any additional RAM. This increase caused the change to be dubbed the ‘Memory vTax’.

When VMWare first announced this pricing change the memory allowance per license were rather low, meaning (obviously depending on the configuration of the virtual machines) some VMWare customers were looking at their licensing costs being several times what the old pricing structure would have cost. Reacting to the complaints of their customers VMWare have now raised the cap, which should keep the license costs to a more reasonable level for most customers.

Here at GloNetworks we’ve always tended towards the Microsoft Virtualization software ‘Hyper-V’ over the VMWare options, and right now we’re more confident than ever in our choice. It could be argued that WMWares virtualisation software is more ‘feature-full’ however we feel that Hyper-V’s pricing has always been more appropriate for us and our customers’ requirements. And since Microsoft have appeared to confirm they have no plans to use a similar ‘Memory Tax’ in its next Hyper-V product (Windows Server ‘8’ Hyper-V) we’re sure this will continue to be the case.

Posted by James in Applications, General, Operating Systems, Servers | 1 Comment »

After being unveiled to the public some 9 months ago Apple’s new operating system sees its release today. So congratulations expectant Apple fans: It’s a Lion! Or OSX Lion to be more precise.

As the newest edition of Apples popular OSX family of operating systems Lion has great pedigree. Previous OSX versions (Tiger, Leopard, Snow Leopard etc.) have been very well received. But when you look at the interface changes and new features in Lion another source of inspiration is also apparent; Apples iPhone and iPad operating system iOS.

OSX Lion is available from today, from the Mac App Store, for £20.99. Unlike other OSX releases there is no hard copy available; it’s a download only purchase.

We’ve not yet had a chance to play with Lion but rest assured, once we’ve got our teeth into it we’ll report our thoughts on the new OS here on the blog.

Posted by James in Desktops and Laptops, General, Operating Systems | No Comments »

Google has got a question to ask you: What do you love?

Their newest service takes your answer and pulls results from a plethora of Google services. It then displays all the results it gets from these in boxes (1 box per service) on one results page.

While searching across the numerous services Google provides could be a handy tool, unfortunately, at the moment it feels a bit like a cheap advert for everything Google.

Some of the boxes don’t really display search results, but rather just contain automatically generated image showing an example of how your search term could be used on the specified service (for example when we tried the search term ‘God’ the Google Calendar box shows a diary with an event for today’s date called ‘Date with God’). At the moment the best use for the page is probably just to find Google services that you may not even know exist.

Although the ‘What do you love?’ site is active at both www.wdyl.com and www.google.com/whatdoyoulove/ there’s not yet been an announcement from Google regards the tool. Also there is a box on the results page that states ‘More coming soon!’. Perhaps this means that Google intends to change some things before officially announcing.

Posted by James in Cool Stuff, General | No Comments »

As promised in “Our New Private Cloud Platform“, I’m about to divulge all our secrets. Or at least some of them. In vague deal.

I should warn you that this is a blog post aimed at technical people, who have some knowledge of Hyper-V clusters already, so if you’re looking at this from a “users” point of view you may get very lost, very fast. I’m not going to explain every little detail, because quite frankly we’d be here all day.

I feel I should start off by defining our “Private Cloud”. Cloud is term that thrown about a lot recently by marketing staff, and for that reason technical staff need to use it in front of boards and in front of the decision makers. To us techies it may be frustrating, however it’s the world we live in. If you’re uninitiated it’s a very broad term that covers:

• Infrastructure as a Service (IaaS) – Server and networking hardware, possibly server OS, such as Amazon’s AWS,
• Software as a Service (SaaS) – Software provided by a remote system, such as Google Apps (Mail, Docs, etc.), or Dropbox,
• Platform as a Service (PaaS) – Normally software infrastructure for developers to rapidly build software, such as force.com, Google’s AppEngine, or parts of Azure.

Whilst we also provide SaaS products, in this instance our small “Private Cloud” we see as an IaaS offering. It’s a small, 2 node, Hyper-V cluster that we use to run our own and customer’s systems.

As a rough outline our cluster consists of:

• 1x HP Procurve 2810-24G as our main switch,
• 1x Juniper SRX210 acts as our firewall and gateway device for some portions of our network,
• 1x IBM x3250 M3 acts as our physical Active Directory Domain Controller, and also hosts our Data Protection Manager (DPM) 2010 and System Center Virtual Machine Manager (SCVMM) virtual machine under Hyper-V,
• 2x IBM x3550 M3 act as our Hyper-V nodes,
• 1x IBM DS3512 acts as our shared storage,
• 1x QNap TS-459U+ acts as our short term backup storage,
• Several USB hard drives for off-site backup that are routinely swapped.

We’re aware that there are some issues with this design; single switch, single firewall and only 2 Hyper-V nodes. However the importance here is why we chose some of these things and why we don’t care as much right now (this was a significant investment for our small company);

1. Granted all hardware does die. In the event that a switch does we can get one on-site reasonably quickly if we needed to, however we’re yet to have a HP Procurve die on us since we’ve started business,
2. Single firewall is something that we worry about, but we’ve chosen Juniper as they are easily clustered,
3. Provided that you don’t over subscrbe 2 Hyper-V Nodes should be sufficient, however additional nodes can be introduced to the cluster easily in the future.

So whilst we are aware of the problems, I believe that we’ve engineered the system in such a manner that we’re able to introduce new hardware easily, upgrade the existing hardware, and provide some additional redundancy, including multiple switches with multi-chassis LACP links.

We’ve not built this system to compete with Amazon’s amazing AWS, however we have built it with 3 goals in mind:

1. Extensibility,
2. To use as a small reference design,
3. To virtualise our own systems more redundantly. The fact we’re able to host customer’s systems as well is a nice perk.

I won’t take you through the process of setting up your Hyper-V cluster, but I will cover a few bits and bobs that we feel a techy should be aware of before walking into a project like this, but might forget when looking at the big picture.

Clustered Shared Volume, or CSV, is the magic that makes the shared storage work. It’s a clever file system that allows multiple nodes to share the same storage. We’re yet to deploy a CSV using FC so we’re unsure if this is true for FC as well, however in the instance of both DAS and iSCSI what happens is the following;

1. The master node takes control of the storage,
2. All other nodes are notified of this, and effectively redirect all storage requests for the shared storage to the master node, over the network.

It should be clear from this that your choice of network card and switch are very important.

CSVs are not supported by Microsoft for any other use other than Hyper-V clusters. So don’t go getting any ideas.

Jumbo frames on your networking gear is a must. Generally speaking a Jumbo Frame is any ethernet frame that exceeds 1500 bytes, however they’re commonly also used as a naming convention for frames of 9000-9600 bytes (+/- 14 bytes for the header, depending on your switch(es)/NIC configuration language). If you don’t remember how IP and ethernet interact I suggest you go and refresh your memory very quickly. You should recognise the importance of having Jumbo Frames enabled very quickly; it should provide higher performance in situations where large payloads are being transmitted frequently.

At present we’re using Microsoft’s DPM 2010 to backup. The major gotcha that we didn’t see was that DPM 2010 on a Domain Controller is basically a no-no:

For a DPM server that is installed on a domain controller, only protection of data sources local to the DPM server is supported. You cannot install agents on other computers to configure protection.

SCVMM (System Center Virtual Machine Manager) 2008 R2 needs some polish. We’ve had to dive into the database once already. Don’t be afraid of it.

Other than that the project went exceedlingly smoothly. There are a few features that I wish Hyper-V had, in comparison to VMWare and Xen. And I really do wish that there were more, cheaper, graphics cards out there for RemoteFX.

However, that’s just something to plan for as a future project.

Posted by Karl in Applications, General, Hardware, Operating Systems | 2 Comments »

Microsoft are soon to release their new Windows Thin PC operating system, also known as WinTPC. In fact the product has been in the RTM (‘release to manufacturer’) status since early this month. If you’re not aware of the product, it’s essentially a stripped down (and locked down) version of Windows 7 which requires less resources to install and run.

The product is designed to allow old hardware, which may not have a good enough spec to support newer operating systems, to be used as ‘thin client’ devices. Thin clients are computers which rely on other computers to the traditional computing tasks (processing, data storage etc.), while the thin client usually is responsible for just displaying the user interface.

At Glo Networks we were very interested in WinTPC, some of our customers use thin client devices quite effectively, and being able to repurpose old desktops and laptops for this would be a great way to re-use them (we all know reusing is the most efficient way to recycle!). Also WinTPC is capable of utilising RemoteFX, a new Remote Desktop technology which can be used to make connecting to a virtualised remote machine visually almost exactly like running it on the local machine (including running 3D graphics and full motion video). This could mean that with WinTPC your old hardware could offer a user experience close to that of a new, built for Windows 7, machine!

We have been testing the software, and we were looking forward to being able to offer the product to our customers. However when investigating the licensing of the product we came across an important, and disappointing detail: WinTPC licenses will only be available for use on devices that are already covered by ‘software assurance’ (SA).

While this is great news for those with SA, there are many businesses for whom SA is too costly or simply isn’t necessary. They will not have any opportunity to buy WinTPC retail licenses for their old hardware and, as such, said hardware will be likely either be relegated to the storeroom to gather dust (hardly an efficient use of the money invested!) or be disposed of (not too eco-friendly!).

In conclusion, while we are happy with WinTPC as a product, and it will no doubt be a great be benefit to those with SA, we are certainly disappointed that it won’t be more widely available.

Posted by James in General | No Comments »