Summary: Bridging the Information Gap in Storage Protocol Stacks
Timothy E. Denehy, Andrea C. Arpaci­Dusseau, and Remzi H. Arpaci­Dusseau
Department of Computer Sciences, University of Wisconsin, Madison
{tedenehy, dusseau, remzi}@cs.wisc.edu
Abstract
The functionality and performance innovations in file sys­
tems and storage systems have proceeded largely indepen­
dently from each other over the past years. The result is an
information gap: neither has information about how the other
is designed or implemented, which can result in a high cost of
maintenance, poor performance, duplication of features, and
limitations on functionality. To bridge this gap, we introduce
and evaluate a new division of labor between the storage sys­
tem and the file system. We develop an enhanced storage layer
known as Exposed RAID (E×RAID), which reveals informa­
tion to file systems built above; specifically, E×RAID exports
the parallelism and failure­isolation boundaries of the storage
layer, and tracks performance and failure characteristics on a
fine­grained basis. To take advantage of the information made
available by E×RAID, we develop an Informed Log­Structured

Source: Arpaci-Dusseau, Andrea - Department of Computer Sciences, University of Wisconsin at Madison
Arpaci-Dusseau, Remzi - Department of Computer Sciences, Department of Computer Sciences, University of Wisconsin at Madison

Collections: Computer Technologies and Information Sciences