Tag: Sunshine Coast

There is a lot of differing information concerning the disk space required to delete snapshots and have them merge back into the original VHD in a Hyper-v Virtual Machine.

Usually these conversations are forum posts where Sys Admins have performed a snapshot on purpose or by accident early on in the Server’s life and are now facing the prospect of merging back a massive differencing disk (AHVD) that has consumed what was left of the physical disk. The advice from others is usually to export the Virtual Machine to a larger disk, perform the merge and export and import it back again. This may or may not however be required (depending on your case) and wasn’t in our case, so please read on for a real world scenario.

Hyper-v Virtual Disk Types

Now I think that the varying reports on Hyper-v snapshot merging has come about because there are different types of Virtual Disks VHDs available to you in Hyper-V.

Hyper-v Disk Types

If you run in a production environment the consensis seems to be that running a fixed Size VHD is the best option. When you first create this type of disk it expands out and claims the physical disk space. This process can take a while, howevever with a new physical disk in the system this is great because it will likely claim a chunk of continuous space on the disk. You can expand the disk size in the future if you have more physical space but you can’t shrink it.

A dynamically expanding disk is another type of beast. It is fantastic for a lab because it only consumes from the physical disk what it uses in space. Over time though this type of disk could get so large that it fills your physical storage so beware. There are also overheads in constantly increasing the size of the VHD. I don’t recommend using them except in your lab, but they are important to be aware of in the case of snapshot merging.

Our Scenario

We provide IT Support on the Sunshine Coast and have been working a lot with Microsoft Virtualisation technologies. For this client we provided a 2008 R2 box running Hyper-v and a virtualised SBS 2011 running in it. It was a new install and a snapshot had been taken during the install process. Now Microsoft recommends not taking snapshots ever this to a production machine or any DC (there can be issues in rolling back to a snapshot) so don’t do it. There seemed to be no harm done in this case. Also, the snapshot button is so close to the VM Start that you might even accidentally hit it one day. A word to Microsoft – a great idea would be a switch to globally disable the ability to Snapshot.

The server had been happily running for a week and then we found the disk space was decreasing too fast on the host. Further investigations showed the snapshot was still on the system and the snapshot AVHDs had grown in size for the primary System VHD and the Data VHD. The Primary System VHD was 188Gb and the snapshot AVHD had grown to around 47Gb. The Primary Data VHD was 270Gb and the AVHD 12.5Gb. The original VHDs were Fixed Size disks which really helps in the merging scenario.

Hyper-v Snapshot Sizes

The Backup

We took a Hyper-v export of the Virtual Machine to an external drive as a precaution before performing the merge because of all the horror stories on the internet regarding merging. This is one of Hyper-v’s best features and allows you to move an entire virtual machine to another Hyper-v host if required. Simply shut down the Virtual Machine and then choose export from the sidebar menu (the option is not available when it is running).

The Merge into Fixed Disk VHDs

The actual merge was suprising. Being a fixed disk the differencing disk is played back into the existing space used by the VHDs. Here is a screenshot of part way through the process. The key was that there was absolutely no change in the physical space used on the hard drive. No these drives were RAID 10 SAS 10K so they perform well. The entire merge took 15 minutes from start to finish. That is merging around 60Gb of differencing disk.

Hyper-v Snapshot Merging

As the process got towards the end the physical disk actually gained some free space as one of the AVHDs was probably deleted in the merge.

Hyper-v Merging Snapshots

The AVHDs in this scenario were manageable. We haven’t tested it but there may be a problem if the AVHD gets bigger than the original Fixed size VHD. How that scenario would be realised I am not sure because of the physical limit on the original VHD – please comment if you have experienced in this.

But what about Dynamically Expanding VHDs

Well we haven’t tested this case in production, but Mooky32 on the Windows Server Forums has posted some lab tests in which he found that with a dynamically expanding disk you will require free physical space of up to the current size of the AVHDs you are merging. In our case that would mean we would need 60Gb of free space to perform the merge. This makes sense because as the AVHD is played into the dynamically expanding VHD it would need to expand out. Where this seems to be a problem for other admins is where a snapshot has gone un-noticed for some time and has taken up a majority of the physical drive leaving no space to expand the original VHD. In this case you would be forced to perform an export to a drive with enough free space, merge and then export and import back.


Our production result confirmed what Mooky32 found in his test lab. With the merge of a AVHD that was smaller than the original Fixed Size VHD, we found there was NO requirement for additional free space on the drive. Also the speed at which the merge occured was suprising.

Disclaimer: We are providing this information as background reading. Please consult official Microsoft documentation before performing any of the tasks outlined in our article. We do not accept responsibility for any loss, expense or liability that you may incur from using or relying on the information contained here.


Almost every business has a person in-house who is the “go-to” person to solve IT issues. You may even be that person in your business?  What OJ Networks often seen though is that if the issue is a complex one or if there more than just a couple of staff to support, then this person spends a lot of time trying to solve these issues, at the expense of the work they are paid to complete.

In cases like this, two of your staff are now not working on core tasks. This can also cause unwanted stress as they try to catch up on their paid work. Make no mistake – having an IT savvy person in-house can be fantastic for solving small issues, but if they need help with something that is over their skill level, then having a trustworthy IT professional to call makes sense. IT Professionals have either seen the problems before or can intuitively find the solution to new problems quickly. This allows your business to get on with what it does best and keeps your staff happy and productive.

Some other benefits of getting an IT Professional to look at your issues are that they might have a solution that you did not know about to an ongoing issue. Things like using DropBox to share documents between offices or with employees who are out in the field. Or installing an Exchange Server or Exchange Online Solution to benefit from the power of having your email, contacts and calendar that stays in sync with you everywhere.

If you are looking for a IT company to look after your business on the Sunshine Coast then give OJ Networks a call!


Got a great idea for a website? Here are some key points to take on board when filtering through the hundreds of choices in web designers.

(1) Are they local? Having a great designer in another state or country might seem feasible but in the back and forth of design and implementation – nothing beats a face-to-face meeting. Being on the coast means they will understand your business.

(2) Are they actually performing the work? Many Australian companies have a sales front and send the coding and/or design work offshore. Usually cheaper but you’re not supporting Aussie Jobs and when things go wrong the locals may not have the technical skills to fix it.

(3) Are they willing to help you with goals and strategies as part of their quote? You may have a plan for your site but a good web designer can give you a great site plan and focus on “calls to action” – getting your customers to act on your goals.

(4) Have they built a number of high traffic sites before? Nothing substitutes for experience. Having some high profile or high traffic sites under their belt means a web designer has seen and solved the many issues a more complex site involves.

(5) Are they providing a complete solution for social media and marketing? Facebook, Twitter, Analytics,  SEO, Google Adwords – you will want to utilise these tools and more to market your brand to the full spectrum of opportunities available.


OJ Networks answers ‘YES‘ to all of these questions for businesses looking to bring their Sunshine Coast business online or create a website on the Sunshine Coast.

TickWe are local – based in the heart of Coolum Beach – our offices are easy to find (across from Tickle Park) and we are always ready to meet face-to-face with you to discuss your online ideas. We know what makes Sunshine Coast businesses tick. We understand the tourist economy and how to market to it online.

We have highly skilled designers and coders on our staff. We can design custom templates from scratch. If you want a cheaper option we can utilize a pre-designed template and modify it to your needs.  If something isn’t right with your site coding we will fix it.

TickToo many sites on the net are simple brochure sites. They have no call to action and no reason for people to interact with them. For example – if you are selling a product or service your goal should be to get people to enquire or purchase from you. We are experts in funnelling your visitors to these goals which results in more revenue for your business and really makes your site worthwhile.

TickSites we have built attract thousands of visitors a day. They are fast and responsive. They are functional and easy to navigate. Whatever your requirements we can deliver an online product to make your ideas a reality.

TickWe believe in empowering our customers. As part of our packages we integrate with tools such as Google Analytics and Google Webmaster to allow our customers to track how their site is performing. We integrate with Social Media such as Facebook and Twitter to begin social interactions for our customers. We can help setup AdWords and facebook advert campaigns to boost your traffic overnight.

Contact Us Now regarding your web project See some of our Sunshine Coast Web Designs