Hardware Reference
In-Depth Information
Chapter 30
Storage Models: Past, Present, and
Future
Dries Kimpe and Robert Ross
Argonne National Laboratory
30.1
The POSIX Era :::::::::::::::::::::::::::::::::::::::::::::::::: 334
30.2
The Current HPC Storage Model :::::::::::::::::::::::::::::::: 335
30.2.1
The POSIX HPC I/O Extensions ::::::::::::::::::::::: 335
30.2.2
MPI-IO :::::::::::::::::::::::::::::::::::::::::::::::::: 337
30.2.3
Object Storage Model ::::::::::::::::::::::::::::::::::: 337
30.3
Post POSIX :::::::::::::::::::::::::::::::::::::::::::::::::::::: 338
30.3.1
Prior Work ::::::::::::::::::::::::::::::::::::::::::::::: 338
30.3.2
Object Abstractions in HPC :::::::::::::::::::::::::::: 339
30.3.3
Namespaces :::::::::::::::::::::::::::::::::::::::::::::: 341
30.4
Conclusion :::::::::::::::::::::::::::::::::::::::::::::::::::::::: 341
Bibliography :::::::::::::::::::::::::::::::::::::::::::::::::::::: 342
The storage component of HPC systems, like most components in these sys-
tems, is built of parts borrowed from other communities and markets. Early in
the development of HPC systems it was recognized that a globally accessible
storage system was desirable, and the HPC community converged on the use
of the Portable Operating System Interface for UNIX (POSIX) I/O model
as its de facto standard: a globally accessible directory tree holding files that
each contain a stream of bytes of user data, with a strong consistency model
enforcing immediate (global) visibility of updates.
As systems have grown in scale, supporting this model has become increas-
ingly problematic, both in terms of performance and in terms of reliability. In
this chapter we will discuss the POSIX model, how the HPC community has
worked to adapt the POSIX model over time to meet its needs, and alternative
models that are emerging from current research.
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