Category Archives: Architecture

Infrastructure as a Service (IaaS) …what does it mean?

Most schools in Australia are now moving beyond asking “what is cloud computing?” and on to “how can we implement cloud computing?”. Now that cloud is a popular solution, the major decisions to make become what kind of service to use and when.

Cloud Services come in many different shapes and forms, such as Software as a Service, Platform as a Service, Disaster Recovery as a Service, Backup as a Service, Database as a Service etc. One of the most common on offer is Infrastructure as a Service (IaaS).

What is IaaS?

Infrastructure as a Service (IaaS) is a model where the IaaS provider hosts infrastructure components on behalf of the school. There are many different possibilities including virtual servers, firewalls, load balancers, and network connections. I wanted to go through a few of the major advantages that come from IaaS as well as some disadvantages.


In my opinion the single greatest strength of IaaS is its scalability. Schools have been known to need rapid response from ICT and historically ICT has not been able to respond as quickly as the school needs. With IaaS, resources can be made instantly available for sudden spikes or drops in demand, effectively eliminating any downtime needed to add to or adjust their infrastructure.


One of the biggest drivers for schools to adopt cloud computing in general and with Infrastructure as a Service specifically, is the way it can cut costs. Since cloud computing is done over the internet, schools don’t have to spend the time, manpower or money on investing in hardware and infrastructure of their own. All of this is handled by the IaaS provider. That means schools don’t have to worry about all of the problems that come with maintaining, powering or cooling their own equipment.

One of the other ways that costs are lowered is by the reduced need for highly skilled IT personnel; the focus moves from IT infrastructure to learning and educational outcomes and working with teachers and staff to provide a better service. With more time on their hands, don’t be surprised to see IT come up with some creative ways to contribute to the schools projects and day to day.

Another big advantage IaaS brings to the table is its pay-as-you-go model. This pay for what you consume model has gained a lot of attention and interest, this has helped reduce ICT wastage or over provisioning.


As with any technology, there are a number of disadvantages with IaaS. One concern is that of security. It’s the same concern that surrounds all of cloud services, and it is that the schools data stored in the cloud can be more stolen or lost. In essence it should be noted that data is frequently more at risk or equally at risk on school premises. This remains one of the main reasons that some schools avoid cloud computing.

Another disadvantage comes from vendor outages, where IaaS vendors suffer networks and service crashes, leaving customers unable to access their systems. Vendors can only address this problem by promising quick recovery time and by giving assurances around data recoverability and security.

Choosing an IaaS Vendor

The choice of IaaS service provider is important as schools are not only seeking, high quality, reliable service and support but also a partner that understands the school and the business of education.
It is wise to select a partner who understands education, teaching, learning and also understands IT services. Having a close intimate relationship and understanding of education is paramount in selecting the school’s cloud service provider.


To close off and summarise, the movement we have seen in the education sector towards IaaS is due to schools feeling that the benefits gained from IaaS make a school more flexible and efficient. IaaS can in a lot of cases cut costs and enable ICT to deliver more services more quickly while leaving room for innovation and a tighter focus on the educational outcomes that the school is driving towards.

EMC VNX2 SAN Storage

Recently EMC released their upgraded storage platform the VNX2 or Next Generation VNX. There are actually quite a few changes to the hardware and capabilities of this platform that are really impressive and worth a look. Also a lot of marking spiel and numbers that will need to be proven in our real world environments to be believed.

Let’s start where it began to get a good understanding of where it’s going and to have something to measure the improvements against.

The EMC VNX Series SAN has been a pretty damn reliable and solid platform that my customers have been very happy with over the last several years, EMC has some impressive numbers around how many they’ve sold.

  • More than 3,600 PBs shipped
  • Over 500 customers purchasing more than a PB of storage
  • Over 71,000 Units shipped
  • SSD’s have gotten traction in the enterprise with over 200,000 SSD’s shipped, this boils down to over 60% of the VNX Series shipping with at least some Flash

All very impressive and substantial numbers and figures. I have been involved in the architecture and design as well as deployment of about 30 VNX Series SAN’s from the VNXe 3300 to the higher end of the scale. In all cases I’ve found that building an understanding of the customers’ requirements and then ensuring that they are met by the solution recommended is key. Storage isn’t just about TB’s and Drives anymore and Virtualisation changed so many aspects of how the Data center is designed and operated that in essences the storage array can be thought about as the foundation of the data center. Without that foundation meeting requirements then everything that sits on top of it will be impacted, from the Hyper-Visors, operating systems, applications, business services, etc. once these are impacted blame gets thrown around to the network, wireless, internet and other IT services.

Today’s Storage Area Network Arrays have to support a large number of physical hosts, an even larger number of Virtual machines and possibly thousands of applications, with workloads and demands that can fluctuate and change significantly with no warning. It will be interesting to see how EMC’s Next Generation VNX series adapts to and handles this workload.

EMC like a lot of vendors have adopted Flash as the key to the future of storage design. This works to ensure that the focus is on optimizing for both performance and cost. EMC is leveraging their investment in the FAST suite of technologies from the original VNX and this is a great place to start as it’s proven that a very small amount of flash can serve a very high percentage of the overall IOPS and typical workloads. Hybrid arrays are a great balance.

As with all things new and shiny and ‘Next Generation’ almost everything is faster.  Faster CPUs with more cores.  More RAM.  Better I/O. It all works together to get things get done quicker, the new VNX’s scale up to over 1 Million IOPS.  Up to 3PB.  Can do 200,000 IOPS in a 3U package. All in all pretty damn impressive!

I’ll detail the biggest changes around VNX below;

  • Vault Drives now use 300GB per disk for the operating system, eg if you put 4 300GB drives in as vault you will not be able to provision anything on them.
  • System cache is now one pool, there is no assigning read cache/write cache or watermarks, also it is set to 8K. Cache allocated for write is still mirrored to the other service processor
  • FAST Cache disks can be used for FAST VP, but FAST VP disks cannot be used as FAST Cache
  • FAST Cache will now promote single page read requests until it hits 80% capacity, then it will defer to 3 read promotion.
  • Hot Spares are now managed by the system, you don’t manually assign disks as hot spares, you apply a policy to a type of disk and the system will automatically select hot spares based off that policy
  • Drive mobility – you can move disks between any DAE or slot in the system and it will still be a member of the same raid group/pool, this allows you to move DAE’s between buses if you are doing an array expansion, also if a disk reports a failure, you can’t remove it and re-add, the system won’t allow the disk to be re-used.
  • Permanent sparing – when an array rebuilds to an assigned hot spare, that disk will become a permanent replacement.
  • Rebuilding RAID groups now uses write logging to LUN metadata, when a disk fails or goes offline writes will be logged like a journal to the RAID group so when a rebuild takes place there is less time required as parity is not being calculated to rebuild.
  • Symmetrical LUN access replacing ALUA is only available on Classic/Traditional LUN’s with the initial VNX2 release, it is not available on storage pool LUN’s and  also the host has to have updated native multipathing or power path software to support this.
  • By default LUN’s in storage pools will be provisioned thin now
  • The array now supports block level deduplication
    • Deduplication is scheduled, rather than in-line
    • Chuck sizes are 8K so host filesystem cluster sizes should be sized accordingly
    • A storage pool can have one deduplication container, but the storage pool can contain mixed thin/thick luns and dedupe volumes.
    • A dedupe volume is tied to a single service processor, so when creating multiple dedupe pools they should be balanced between processors
    • The dedupe container with in a pool is basically a private LUN containing every chunk from every deduped LUN in it, FAST Cache and FAST VP teiring policies are applied to the whole dedupe container, not individual deduped LUN’s so this needs to have design considerations when mixing Fast/Slow LUN’s.

VNX2 Datamovers support SMB 3.0 now, this may not seem like a big thing except now Windows 2012 Hyper-V allows you to use SMB 3.0 to provision shared storage for VM’s on CIFS rather than needing block shared storage, so for a Hyper-V setup you can look at hosting your VM’s through CIFS folders via VDM’s rather than via FC or iSCSI.

What is Infrastructure Architecture?

What is Infrastructure Architecture?

I will be the first to say that it’s a very broad role title and I’ve asked a number of people what it is, every one of them gave me a different answer.

To add complexity to what is already a complex area is the growth in Cloud infrastructure which has and will continue to change the role of the infrastructure architect. I’ve heard this referred to by a college as a virtual architect, a comment that I thought was very fitting.

Architecting a Data centre deployment today is a very different task than it was even 3 years ago, let alone 5 to 10 years ago. Virtualisation came along and turned everything on its head and changed an entire profession in a staggeringly short period of time, and now cloud is coming along and could do the same thing for many people and organisations. Careful and accurate sizing, location, power consumption, rack location, connection type, etc. are now unnecessary for applications in a datacentre where you are consuming IaaS or SaaS offerings. In an example of your own Data Centre or Infrastructure you may be able to increase you compute or Memory capacity by adding blades to an existing Blade chassis without any additional rack space consumed.

In today’s infrastructure it’s not at all uncommon for an infrastructure architect to build something that is running entirely on a virtual infrastructure and doesn’t consume or require the additional of any new hardware. Recently I architected and deployed an infrastructure consisting of Firewalls, Routers, Switching, load balancers, multi-tiered applications, domain services, and client access all without touching a physical piece of kit or even walking into the data centre. I believe this will continue to become more common all the time.

So what is an Infrastructure Architect?

An Infrastructure architect is the person or people who take the requirements and constraints defined by the the business, collaborate with the key stakeholders and staff, and design the supporting environment for the solution. Infrastructure Architects will normally work very closely with Enterprise and Solution Architects to architect an infrastructure that will support the solution that the solution architect puts forward. They will work at a high level and work with functional and non-functional requirements set by the Enterprise and Solution Architects.

I always try and keep it clearly defined and differentiated that architecture is not engineering or delivery, when doing engineering I am highly focussed on the how of a solution, How to deliver it, how to power it, how to configure it, how to setup a storage pool or resource cluster, how to connect x to y, etc.

Architecture can be seen as the philosophy that underlies any system.  It defines the purpose, intent, and structure of a system.  Architecture is the discipline of addressing business needs and requirements with people, process, and technology.  I also try and maintain awareness of what domain I’m working in, There are various perspectives or kinds of architecture, including enterprise architecture, business architecture, data architecture and application architecture, all of these are very different and yet very similar to infrastructure architecture.