In a two-part article, David Barker, founder and technical director at green colocation and connectivity supplier, 4D Data Centres, discusses the different types of external storage and how best to decide which one you should be using for your critical data.

Storing data outside your organisation is the flavour of the day at the moment, whether it is in the ‘cloud’ or on your own hardware but colocated with a third party.

How do I decide which type of storage is best for my data?

If you’re looking at where to store your data you have three basic choices. There are variants and combinations of these such as a private cloud within a colocation data centre, but for now we’ll stick to the following:

  • Internally hosted
  • Public cloud storage
  • Colocation

Internally hosted data

This provides you with the greatest control of the data but will cost you the most to run. You will be able to manage the hardware directly, have complete control over access to the building and only your staff (who should already be vetted) will have physical access to the machines.

This makes internal hosting ideal for sensitive commercial or personal data where security is paramount, or data for which low-latency is required.

The disadvantages of hosting all your data internally is that it costs a lot to set up just a small comms-room or data centre and even more to run it on an on-going basis (from electricity to maintenance agreements for aircon).

Public cloud storage

Public cloud storage has the least control and security of all three options. However it does have advantages in that you can usually access your data from any location, provided you have an internet connection, and there is usually very little upfront cost in getting the storage available. But you can’t always control which country your data is stored in, which can have implications for data protection, latency and speed of access (e.g. data stored in the UK will be faster to access from the UK than data stored in Australia).

Data stored on a public cloud should only be data that you are prepared to have in the public domain. In my opinion you should never put commercially sensitive data onto a public cloud environment, but it is an excellent location to store content for websites such as videos, sales brochures and other downloads.

You will generally access cloud storage over the public internet (in some cases VPN support may be available), but generally the connection will be unencrypted and limited to the speed of your local internet connection.


Colocation is the middle ground between internally hosting all your data and putting it all onto a public cloud. It has the advantages of the former in terms of security and control over your own hardware, while having the flexibility and lower upfront costs of cloud hosting.

When you colocate your equipment and data you are putting it into a specialist data centre. The data centre then provides all the security, facilities, engineers and network for your equipment as part of a monthly fee, removing the burden of managing these internally. The data remains on equipment that you own and will be hosted within a lockable rack so that it is separate from all other clients within the same building.

Colocation provides an environment where, depending on how you structure your own equipment, you can store sensitive commercial data, publically accessible data and low-latency requirements.

Part 2 covers how to access externally stored data and how to deal with latency issues.

Posted by David Barker, founder and technical director at green colocation and connectivity supplier, 4D Data Centres