Storage Networking Architectures
Direct-Attached Storage
DAS Strengths and Limitations
� Low scalability:
� Inexpensive hardware
� SCSI bus device limit
� Mature, standards-
based
� Need for multiple servers
� No server scalability
� Familiar technology
� Limited availability:
� No retraining needed
� RAID does not protect from
server h/w or s/w failure
� Limited distance for SCSI
� Difficult to manage:
� Data is dispersed over
many servers
Strengths of DAS:
DAS hardware consists of relatively inexpensive commodity products.
SCSI technology has been around for decades, and there are few
interoperability issues between different vendors’ hardware.
Nearly all industry-standard server administrators know how to manage
SCSI-based storage, and IT organizations do not have to invest time and
money in training their storage administrators.