IT:AD:Direct Attached Storage (DAS)

Most physical computers are DAS, in that hard drive is directly accessible, without having to go over the network.

“One drawback to both the NAS and SAN architecture is that the connection between the various CPUs and the storage units are no longer dedicated high-speed busses tailored to the needs of storage access. Instead the CPUs use the LAN to communicate, potentially creating bandwidth as well as performance bottlenecks. Additional data security considerations are also required for NAS and SAN setups, as information is being transmitted via a network that potentially includes design flaws, security exploits and other vulnerabilities that may not exist in a DAS setup.

While it is possible to use the NAS or SAN approach to eliminate all storage at user or application computers, typically those computers still have some local Direct Attached Storage for the operating system, various program files and related temporary files used for a variety of purposes, including caching content locally.”