DIO
Distant I/O Library
for One-Sided Access to Remote Storage
Distant I/O (DIO) model applies
the concept of one-sided communication to parallel I/O on clustered systems
with attached disks.
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DIO facilitates data transfers
between files on remote nodes and local memory.
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DIO not require installation
of special daemons or server processes to service remote I/O requests
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avoids significant CPU and memory
overheads
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compute nodes become part-time
servers and part-time clients
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Relies on efficient lightweight
communication protocols such as Active Messages
DIO has been implemented on
the IBM SP using LAPI
Active Messages and Posix asynchronous I/O.
Performance of DIO operations
on IBM SP is very close to that of local operations for request size >16KB.
Applications
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Shared Files: one of parallel
I/O libraries developed by ChemIO
project uses DIO to provide a shared file view with independent file pointers
on collection of local disks on compute nodes of the IBM SP.
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An out-of-core version of COLUMBUS,
a computational chemistry application, used DIO to solve the largest ever
multireference configuration problem. A paper describing this implementation
has received the Best
Overall Paper Award at SuperComputing 98 (SC'98)
conference in Orlando, Fl.
More Information
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A copy of the paper presented
at the High Performance Distributed Computing Conference HPDC-7 in July,
1998 is available in the HPDC-7 Proceedings on pages 148-154 and
here.
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An extended version of the HPDC-7
paper titled "Implementing noncollective parallel I/o in cluster environments
using Active Message communication" appeared in Cluster Computing no. 2
in 1999. pdf
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The library can be obtained
by sending email to j_nieplocha@pnl.gov.