Archive for the ‘Uncategorized’ Category

The Importance of Knowing the Internals

November 3, 2010

I know things have been a bit quiet around here of late, most of my spare time is going to my recent editorial duties! But once that is over, things will be taking a slightly different turn around here. I’ll be going back to my roots. Back to the internals. Why? Well the thought kinda kicked off after something Massimo said a few weeks back on Twitter. I completely agree with that on many levels. But on others, I don’t. And the grounds for the “don’ts” are pretty much based in laziness, much in the same way that scripting guru’s are generally the laziest people to be found (yes Lam and Dekens, I’m looking squarely at you :P).


Boot a VM from iSCSI? Yes. We. Can!

October 9, 2010

I was having a chat with someone the other day and we got onto the subject of that most excellent open source project, Etherboot/gPXE. For the uninitiated, gPXE is basically a replacement for the ancient PXE ROM found in pretty much all NICs today, and brings network booting into the 21st century. It gives us the ability to use alternative protocols for the boot media, instead of being restricted to TFTP as the current PXE ROMs generally are. If you want to know more about why this A Good Thing, check out this video.

Anyway, the question was asked if it was possible to boot a VM from iSCSI directly without any involvement from VMFS. Having actually done this quite some time ago, I knew it was possible so I said “yes”, but unfortunately I couldn’t access the memory region that held the answer to the logical next question (how?), and I had to say “I’ll get back to you”.

The only way to do this on physical hardware without using chain loading (ie PXE booting some other program and loading gPXE via it) is to burn the gPXE ROM onto the NIC (I’m conveniently throwing gPXE boot via CD/floppy/USB into the chain loading bucket). Obviously this is not something you would want to entertain with VM’s. But luckily for us, VMware gives us the ability to actually specify a separate file to use for the NIC BIOS! So it’s really quite straightforward, here’s how to do it:

1. Go to the ROM-o-Matic website and create a boot rom with the following options:

2. You should now have a file named gpxe-1.0.1-8086100f.rom.

3. Create a VM with an e1000 NIC.

4. Upload the gPXE ROM file into the same directory as the .vmx file of the VM you just created.

5. Add the following line to the .vmx file:

e1000bios.filename = "gpxe-1.0.1-8086100f.rom"

6. You’re done – you can now take advantage of everything gPXE has to offer.

I tested this out on ESXi 4.1, and it still works like a treat. Why do you need to use an e1000? gPXE doesn’t currently have support for VMXNET3. Since it’s an open source project, perhaps someone from VMware could make that contribution?

Chinwag With Mike!

October 6, 2010

It was long overdue, but a few weeks ago I finally got around to having a chinwag with Mike Laverick. I say long overdue, because he asked me ages ago and I just never got around to it! This is the second video I’ve been in lately, the other was the very last VMworld TV recording in San Francisco (which ironically also had Mike in it, and Justin).

I wanted to have a post ready to go to elaborate more on the whole VMware / dogfood bit, but as you’ve noticed I’ve been pretty busy lately (ie very quiet on the blogging front). And I guess it’s OK for me to say why… I am very proud to say I am the technical editor for the upcoming PowerCLI book from Al, Luc, Glenn, Arnim and Jon! And let me tell you, it ain’t easy when you’re dealing with masters like those guys.

Anyway, I hope you find the chinwag entertaining / interesting, and big thanks to Mr Laverick for asking me on. As I say at the end, if it wasn’t for Mike I might not have gotten far in this field and even this blog might not have gotten far – he was the first one to give me a shout out way back in the day, and my readership grew exponentially for a while after that. So again, Mike, thanks for everything.

Holidays… YAY!

June 25, 2010

Just when you thought it couldn’t get any quieter around here, I go on holidays! I won’t be away for long, unless Great Whites are frequenting the Adriatic these days… in which case I may or may not return in one piece :D. See y’all when I’m back.

Enter the Appliance

June 9, 2010

Today’s announcement of an expanded VMware / Novell partnership was interesting in many ways… the licensing aspect, the support aspect …but none moreso (for me at least) than the virtual appliance aspect. In case you missed that part, VMware will be adopting SUSE Linux Enterprise Server, SLES, as the single platform for their virtual appliances. Whether you agree with the platform choice or not (fortunately the company I work for has been a SLES shop from day one), sometimes it’s more important that there actually is a standard, rather than what the standard is. This is one of those times.

I’ve ranted in the past about the problem with virtual appliances. Everything from the lack of a standard Linux platform even within a single vendor (let alone amongst multiple vendors), to the additional overhead such a model of software distribution would place upon software vendors, to the security needs of the Enterprise around patch response times etc. And today, every single one of those arguments has been nullified in one fell swoop. Hallelujah, someone was listening after all!

If you’re a software vendor looking to adopt the virtual appliance model to distribute your wares then I have some advice for you – if you’re not using SLES for the base of your appliance, start doing so. Now. This partnership will mean doors that were previously closed to virtual appliances will now be opened, but not to any old virtual appliance – it will need to be built on an Enterprise grade distro. And SLES is most certainly that.

You all know I’m not one to drink the Kool-Aid, but it’s things like this that really show the leadership VMware has over the rest. My hat is officially tipped to whoever brokered this deal, it’s exactly what was needed.

Why the Enterprise Isn't Ready for EC2. And Why it Never Should Be.

May 17, 2010

I’ll say from the outset that this post is not an attack against Amazon EC2, nor against IaaS in general. It is merely a consideration of use cases, and end games. Specifically, the Enterprise use case for EC2. I personally use EC2, and for my use case it’s bloody great. For startups, it must be a god send. Same for more mature businesses who are built around 1 or 2 internally developed applications, especially if they are web related. It must be a massive boon for students. But for the Enterprise? No.

Let’s start by looking at some application level requirements to get the most from EC2. First, your application needs to be designed for failure – that means scaling out rather than up, loose coupling of components, and statelessness of the endpoint. Second, you don’t want to run an EBS backed instance (and cop all the IO charges), you want to run the operating system on an S3 backed AMI – again that means statelessness within the OS, and complete automation on this layer from instance creation to destruction. Third, you want management and control over the base image itself to ensure your instances come up pre-patched, secure and ready for action.

The problem is very few Enterprise applications are built this way, operating systems as deployed in the Enterprise certainly are not. Why? Are all Enterprise IT employees stupid? All too often the blame for this is misdirected – it’s not the fault of the application owners, the in-house developers, nor the IT infrastructure people. Ladies and Gentlemen, I introduce you to… the accountants!

New HP CIM Patch Released, Update Manager Still Can't Apply It.

April 28, 2010

A new version (1.3) of the HP ESXi Offline Bundle has been released for ESXi 4.0 Update 1. Now I don’t normally tend to post about patch releases because… well, I just don’t really see the value in posting that a patch was released and leaving it at that. But this is a little different.

Because you _still_ cannot apply this patch via Update Manager.

So once again I’ll ask the question of VMware – what is the point of having an automated patch tool if it can’t actually apply patches like these? Clearly the HP patches are packaged in accordance with VMware requirements, because they can be installed via the vSphere CLI. Yet there is still not an easy way to add patches like this to the VUM repository. Cisco patches seem to be available via a VMware provided online repository, but I’m not asking for that – there needs to be a way to manually add patches to local VUM servers, without pointing the VUM server at a website.

Update Manager does on the other hand continue to offer somewhat useless and redundant guest patching functionality, and even more useless application level remediation for things like BizTalk server. But it still cannot handle patching a host that happens to be running a vCenter VM (yet I can manually VMotion said VM around). And there’s still the unscalable 1:1 relationship between vCenter and Update Manager. I’m not sure what the Update Manager team are working on, but they really should forget about the guests and concentrate on the host patching capabilities, which are far from ideal currently.

The Importance of Showing Others

April 15, 2010

This post is part of a series based on a presentation I did to the London VMware User Group on February 25th, 2010 about the reality of Enterprise scale internal cloud platforms. To find other posts in the series, just look for the tag “Bringing the Cloud Down to Earth”.

We’re finally at the end – this is the last of my observations on the life of an Enterprise Cloud project. And again, it’s not something that we really anticipated at the beginning, and has the potential to create very unwelcome interruptions to development. But on the positive side, it’s massively important – not just to get feedback from the stakeholders that you are on the right track, but to stop yourself from getting so hung up on what you’re _not_ developing that you actually forget about the good stuff you _are_ delivering.

Be Agile

April 14, 2010

This post is part of a series based on a presentation I did to the London VMware User Group on February 25th, 2010 about the reality of Enterprise scale internal cloud platforms. To find other posts in the series, just look for the tag “Bringing the Cloud Down to Earth”.

Agility is another buzzword that goes hand in hand with Cloud, but what I’m referring to here is more aligned with Agile as a philosophy or methodology rather than the conventional interpretation (although of the course the 2 are closely linked). Agile is most often used for software projects, so you may initially think it’s a bit strange to use for something that is as much infrastructure as it is software but trust me, it works exceptionally well.

Think Outside the Infrastructure

April 11, 2010

This post is part of a series based on a presentation I did to the London VMware User Group on February 25th, 2010 about the reality of Enterprise scale internal cloud platforms. To find other posts in the series, just look for the tag “Bringing the Cloud Down to Earth”.

It’s time to get back to the reason for doing all this in the first place – it’s about the business, and the applications.Which is why you need to think outside the infrastructure when it comes to Cloud more than you need to think about the actual infrastructure itself. By that I mean the Cloud is more about logical concepts like service levels / tiers and features rather than HP or Cisco, EMC or NetApp.