A Case for Network-Attached Secure Disks

By providing direct data transfer between storage and client, network-attached storage devices have the potential to improve scalability (by removing the server as a bottleneck) and performance (through network striping and shorter data paths). Realizing the technology’s full potential requires careful consideration across a wide range of file system, networking and security issues. To address these issues, this paper presents two new network-attached storage architectures. (1) Networked SCSI disks (NetSCSI) are network-attached storage devices with minimal changes from the familiar SCSI interface (2) Network-attached secure disks (NASD) are drives that support independent client access to drive provided object services. For both architectures, we present a sketch of repartitionings of distributed file system functionality, including a security framework whose strongest levels use tamper-resistant processing in the disks to provide action authorization and data privacy even when the drive is in an physically insecure location. Using AFS and NFS traces to evaluate each architecture’s potential to decrease file server workload, our results suggest that NetSCSI can reduce file server load during a burst of AFS activity by a factor of about 2; for the NASD architecture, server load (during burst activity) can be reduced by a factor of about 4 for AFS and 10 for NFS. A Case for Network-Attached Secure Disks Garth A. Gibson, David F. Nagle, Khalil Amiri, Fay W. Chang, Eugene Feinberg, Howard Gobioff, Chen Lee, Berend Ozceri, Erik Riedel, and David Rochberg