DAS stands for Direct Attached Storage. It is a digital storage device connected directly to the server, workstation, or personal computer via the cable. In Direct Attached Storage, applications use the block-level access protocol for accessing the data.
There is no need for any network to attach the device to the server or workstation. So, DAS (Direct Attached Storage) is not a part of the storage network. Some examples of this storage device are solid-state drive, hard drives, tape libraries, and optical disk drives.
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 the advanced features.
It is a good choice for those small businesses, workgroups, and departments, which do not want to share the data across the enterprises. It is used in those places which require less number of hosts and servers.
Types of DAS
Following are the two types of Direct Attached Storage (DAS):
Internal DAS is a DAS in which the storage device is attached internally to the server or PC by the HBA. In this DAS, HBA is used for high-speed bus connectivity over a short distance.
External DAS is a DAS in which the external storage device is directly connected to the server without any device. In this type of DAS, FCP and SCSI are the protocols which act as an interface between server and the storage device.
Difference Between NAS and DAS
The following table describes the differences between the Direct Attached Storage (DAS) and Network Attached Storage (NAS):
Difference Between DAS and SAN
The following table describes the differences between the Direct Attached Storage (DAS) and Storage Area Network (SAN):