NAS vs DAS: Which is Right For You?

Thursday, July 9, 2015

As we all know, the amount of data that your business uses is growing exponentially and having continuous access to it is essential for business survival. The two main storage solutions – NAS and DAS – have advantages and disadvantages and need to be considered in relation to your specific storage needs.

Storage is a complicated topic and requires careful planning together with long term thinking. There are a number of factors that need to be considered such as the nature and amount of data, dependency of applications, scalability and budget, before determining the most appropriate storage infrastructure for your business.

Key Storage Considerations:

  • Capacity - How much data do you need to store?
  • Scalability - How much data will you need to store 5 to 10 years from now?
  • Reliability - Can your business survive without its data, files and applications? What would downtime do to your business?
  • Backup and Recovery - Where will you back up files and how often? What would happen if you lost files?
  • Performance - How many employees need to share/access or collaborate on files, from where (remote or in-house) and how often?
  • Budget - How much do you have to spend?
  • IT Staff and Resources - Do you have a dedicated IT staff person to manage your system?

So, you now know what you need. Next you have to decide which option best fits your needs and, in order to do that, you need to understand clearly exactly how each option actually operates.

What is Network Attached Storage (NAS)?

NAS is a file-level access storage architecture which connects to a network. It allows multiple computers/devices in a network to share the same storage space at once. A typical NAS is a completely self-contained appliance with its own operating system, storage and a management interface and simply connects to the server through an existing Ethernet network. NAS offers dedicated file serving and sharing through a network and increases performance and reliability with features like RAID and swappable drives. A NAS device is a shareable resource. Multiple users and computers can benefit. This contrasts in comparison to a DAS (directly attached storage) device which is dedicated to the computer it directly connects to.

What is Direct Attached Storage (DAS)?

DAS is computer storage that is directly attached to one computer or server, usually via a cable and doesn’t use the network. The disks may reside inside the server or in an external cabinet. In both situations, disks are connected directly to the server's storage controller. The problem is that a server can directly support only a limited number of disks.  DAS infrastructure is well-suited in a business environment where the files do not have to be shared between multiple applications or systems.

Let’s now have a look at the advantages and disadvantages of both storage solutions which will help you decide which option is most suited to your business needs.

NAS Overview


  • Many NAS products ship with pre-installed disks, guided by setup wizards, that allow even non-IT people to quickly add storage to a network
  • NAS adds storage by simply attaching to the network rather than to a server so there is no server downtime
  • A lot of NAS products support Active Directory which allows them to be easily designated as a storage device if your business is using Active Directory
  • NAS is an economical way to provide large storage to many persons or computers
  • NAS allows you to provide RAID redundancy to a large amount of users
  • NAS simplifies file sharing and collaboration among multiple users


  • NAS requires IP Address(es) and takes up network space
  • NAS performance can be affected by network status
  • NAS complexity can affect latency speed

DAS Overview


  • DAS, a server with built-in storage, can be a low cost way to initially address your storage needs
  • DAS can be several times faster than NAS (networks are much slower than directly attached storage)
  • As DAS doesn’t use the network it doesn’t need to use IP addresses
  • Maintaining DAS is very simple as it doesn’t require management software


  • DAS expansion requires the expertise of an IT professional
  • DAS has limited scalability which makes it unsuitable for environments with stringent up-time requirements or rapidly increasing storage requirements
  • DAS is a dedicated resource for a single computer and thus can’t be managed over a network
  • DAS requires a special hardware connection
  • DAS is limited by the number of drives that can be installed

Data storage is an important consideration in today’s data driven environment. It’s important to consider both your current and potential future needs when assessing what option to use. Critically, don’t wait until you need more storage before you start deciding what to do.

Advantage Technology Solutions provide advice and recommendations on all data centre services. Call us on 1 300 780 730 if you’d like some assistance.