DAS stands for Direct-attached storage. It is computer storage that is connected to one computer and not accessible to another. The System of DAS is attached directly to the computer through the HBA (Host Bus Adapter).
As compared to NAS devices, its device attaches directly to the server without the network. The modern systems of this storage device include the integrated controllers of a disk array with advanced features.
There are two types of DAS which are as follows −
In internal DAS design, the storage device is privately linked to the server through a serial or parallel bus.
In external DAS design, the server is associated directly with the external storage device. In most cases, the connection between the server and the storage device happens over the Small Computer System Interface (SCSI) or Fibre Channel protocol (FCP).
There are various advantages of DAS, which are as follows −
Low cost − DAS costs are the storage device itself and any drive enclosure. It is cost-effective compared to storage solutions that needed hardware and software to run and handle the devices.
High performance − DAS is connected to the device that needs the data, created to it is fast. Network connectivity and congestion problems do not directly affect DAS.
Easy setup and configuration − Computer systems provided with internal DAS are ready for direct use. External network storage can be used immediately if it’s plugged into a port such as a USB port.
There are various disadvantages of DAS, which are as follows −
No central management and backup − While it’s not an issue for persons or only a few computers using DAS, increasing organizations can run into problems providing that the data saved on DAS is available and backed up. It becomes more difficult and costly than organizing redundancy and backups on networked storage computers.
Poor performance possibility − DAS linked to a computer can be slow to share information with other computers on a network. This is due to performance based on the resources of the host PC.
Limited scalability − DAS is complicated to scale because the number of internal drive bays, availability of external ports, and capacity of external DAS is definite. If internal DAS should be upgraded, the host computer may need to be shut down during the upgrade.