By Topic

Non-Contiguous I/O Support for Object-Based Storage

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

3 Author(s)
Dennis Dalessandro ; Ohio Supercomput. Center, Columbus, OH ; Ananth Devulapalli ; Pete Wyckoff

The access patterns performed by disk-intensive applications vary widely, from simple contiguous reads or writes through an entire file to completely unpredictable random access. Often, applications will be able to access multiple disconnected sections of a file in a single operation. Application programming interfaces such as POSIX and MPI encourage the use of non-contiguous access with calls that process I/O vectors. Under the level of the programming interface, most storage protocols do not implement I/O vector operations (also known as scatter/gather). These protocols, including NFSv3 and block-based SCSI devices, must instead issue multiple independent operations to complete the single I/O vector operation specified by the application, at a cost of a much slower overall transfer time. Scatter/gather I/O is critical to the performance of many parallel applications, hence protocols designed for this area do tend to support I/O vectors. Parallel Virtual File System (PVFS) in particular does so; however, a recent specification for object-based storage devices (OSD) does not. Using a software implementation of an OSD as storage devices in a Parallel Virtual File System (PVFS) framework, we show the advantages of providing direct support for non-contiguous data transfers. We also implement the feature in OSDs in a way that is both efficient for performance and appropriate for inclusion in future specification documents.

Published in:

2008 International Conference on Parallel Processing - Workshops

Date of Conference:

8-12 Sept. 2008