Chapter 1 HPSS Basics
34 September 2002 HPSS Installation Guide
Release 4.5, Revision 2
and the HPSS Movers. This provides the potential for using multiple client nodes as well
as multiple server nodes. PFTP supports transfers via TCP/IP. The FTP client
communicates directly with HPSS Movers to transfer data at rates limited only by the
underlying communications hardware and software.
•Client Application Program Interface (Client API).The Client API is an HPSS-specific
programming interface that mirrors the POSIX.1 specification where possible to provide
easeof use to POSIX application programmers. Additional APIs are also provided to allow
theprogrammer to take advantage of the specific features provided by HPSS (e.g., storage/
access hints passed on file creation and parallel data transfers). The Client API is a
programming level interface. It supports file open/create and close operations; file data
and attribute access operations; file name operations; directory creation, deletion, and
access operations; and working directory operations. HPSS users interested in taking
advantageof parallel I/O capabilities in HPSS can add Client API calls to their applications
to utilize parallel I/O. For the specific details of this interface see the HPSS Programmer’s
Reference Guide,Volume 1.
•Non-DCE Client Application Program Interface (Non-DCE Client API). The Non-DCE
ClientAPI is a programming interface that allows the client program the option of running
ona platform that does not support DCE and Encina. This API does not call HPSS directly.
Instead, it sends network messages to the Non-DCE Client Gateway, which runs on the
targetHPSS system. The NDCG then performs the requested Client API calls for the client
and returns the results. The Non-DCE Client API has the same functionality as the
standard Client API with the following exceptions: it does not support ACL functions, it
does not support transactional processing, and it implements its own security interface.
Client authentication is performed in one of three ways: remote DCE login, kerberos
authentication or no authentication (in case of trusted clients).
•MPI-IOApplication Programming Interface (MPI-IO API). The MPI-IO API is a subset of
the MPI-2 standard. It gives applications written for a distributed memory programming
modelan interface that offers coordinated access to HPSS files from multiple processes. The
interfacealso lets applications specify discontiguous patterns of access to files and memory
buffers using the same “datatype” constructs that the Message-Passing Interface (MPI)
offers. For the specific details of this interface, see theHPSS Programmer ’s Reference Guide,
Volume 1, Release 4.5.
•Distributed File System (DFS).Distributed file system services optionally allow HPSS to
interface with Transarc’s DFSTM. DFS is a scalable distributed file system that provides a
uniform view of file data to all users through a global name space. DFS uses the DCE
concept of cells, and allows data access and authorization between clients and servers in
differentcells. DFS uses the Episode physical file system which communicates with HPSS
via an XDSM-compliant interface. For the specific details of this interface, refer to Section
7.6:HDM Configuration on page 435.
•XFS.HPSS is capable of interfacing with SGI’s XFS for Linux. XFS is a scalable open-source
journaling file system for Linux that provides an implementation of the Open Group’s
XDSM interface. This essentially allows the XFS file system to become part of an HPSS
storage hierarchy, with file data migrated into HPSS and purged from XFS disk. For the
specific details of this interface, refer to Section 7.6:HDM Configuration on page 435.