Browse Prior Art Database

Dynamic File Splitting, Asynchronous Disk-Access Method to Maximize I/O Throughput for Multimedia Systems

IP.com Disclosure Number: IPCOM000104917D
Original Publication Date: 1993-Jun-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 2 page(s) / 74K

Publishing Venue

IBM

Related People

Hu, L: AUTHOR

Abstract

Disclosed is an implementation of a software-based, asynchronous disk-access method that stores a continuous media file among multiple disks to maximize I/O throughput for multimedia systems. This method improves I/O performance by accessing disks in parallel and overlapping overheads. The interface to the underlying file system monitors the best operating parameters for each disk, then splits multimedia data streams onto multiple disks accordingly.

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Dynamic File Splitting, Asynchronous Disk-Access Method to Maximize I/O Throughput for Multimedia Systems

      Disclosed  is  an  implementation of a software-based,
asynchronous disk-access method that stores a  continuous  media file
among  multiple  disks  to maximize I/O throughput for multimedia
systems.  This method improves I/O performance by accessing disks in
parallel and overlapping overheads.   The interface  to  the
underlying file system monitors the best operating parameters for
each disk, then  splits  multimedia data streams onto multiple disks
accordingly.

      The  proposed  method builds a software layer on top of an
existing file system to take advantage of  the  following new
environment  in the personal computing systems.  First, multitasking
operating systems like OS/2* provide  efficient thread  switching
capability  for  asynchronous operations.  Second, a new strategy  in
OS/2  2.0*  disk  device  driver enables  the device driver to
dispatch a list of device commands to a  SCSI  (Small  Computer
System  Interface)  host adapter.  Then the SCSI host adapter can
issue disk I/O commands  to several disks at the same time.  In
contrast, only one disk can be active at any time under DOS or  OS/2
1.3*.  Third,  because the physical size of SCSI disks is shrinking
and the price dropping, personal systems are more likely  to contain
multiple  hard  disk  devices.   Finally, hard disk characteristics
vary significantly from one to another.

      The central ideas of this  method  are  to  dynamically split
a  sequential  file  into  multiple  data streams, to access disks in
parallel, and to overlap overheads  as  much as possible.  When an
application requests to open and write a  continuous  multimedia
data  flow,  the  software  layer searches for available disks and
evaluates their  operating conditions.    Then  it splits the
incoming data, and writes them to multiple disks asynchro...