The storage devices can be as simple as hard disk drives, DVDs, USB drives, memory cards and much more. At home, our storage needs are well-met but in bigger organizations or at an enterprise level, you need to plan the storage types in a more defined way. In offices with a large network of computers where you need to manage large databases and ward-off the storage responsibilities from desktops, there is a need for a centralized storage system. In a complex Network environment, the IT people have to deploy advanced storage system considering not only the current requirements but also the future expansions.
Having said that, there are three major storage types that are primarily deployed by enterprises depending upon their specific storage needs. These storage devices are:
- DAS (Direct Attached Storage)
- NAS (Network Attached Storage)
- SAN (Storage Area Network)
Understanding DAS, NAS, and SAN with Key Differences
To explain DAS in simple language, you can consider an example of a USB storage drive. It is also a type of directly attached storage device, although it is not exactly the commercially available DAS. Now think of dual or a group of external drives connected together and creates an array of a storage device that is connected to a computer. So similar to this is exactly what a DAS is. Most of the DAS units come with inbuilt RAID utility. Below is an example of a DAS from Dorbo technologies. It comes with 5 hard disks and connectivity to your computer is provided with USB C cable.
Apart from USB, DAS units come with many connectivity options. SCSI, SAS are some oif the options. DELL 1200 is other DAS unit with many advanced features and connects to the computer through SAS port and you need additional hardware interface for connectivity. It comes with 12 hard disk bays with a maximum storage capacity of 120 TB.
There are many more advanced and high cost DAS units. The above example is taken only for your understanding.
- Easy setup
- Inexpensive compared to NAS or SAN
- Faster operation
- Does not use the IP address
- Not scalable
- Can’t manage it remotely
Any computer connected in a Local Area Network can be considered a NAS that can be used to share files or folders with other computers or users across the network. So a commercially available NAS will have an array of hard disks just like DAS and additionally, NAS unit will have its own processor and RAM it is just like a computer.
Terastation 3210DN is a 4TB RAID ready NAS. It is compatible with Windows and Mac. You can remotely access the files from multiple devices like Android phone, iPad, iPhone or windows phone through internet.
Another NAS example
- Sharing of resources means higher utilization.
- file and folder level permissions
- Replication and screenshots
- Remote management
- Costlier than DAS but less than SAN
- Data transfer is slow compared to DAS
Just like DAS, you can see the SAN virtual drives on your local computer but SAN is connected to a network and allows sharing of resources with other users. So SAN provides you the speed of DAS and better utilization of resources or sharing features of NAS. You can use the virtual drives of SAN to install individual operating systems in a network. Instead of automatic IP, SANs need static IP addresses.
- Allows virtualization
- Speed better than NAS
- More expensive than DAS and NAS
- Needs multiple static IP addresses
- Resource utilization Scalability is similar to NAS
The post about DAS, NAS, and SAN highlights the basic (surface-level) explanation of types of storage devices used in business without going deep into the technicalities. Finally, it all depends on the business needs and costing while deploying the right storage plan in an enterprise environment.