HPSS. A delog function is provided to extract and format log records from a central or
archived log file. Delog options support filtering by time interval, record type, server, and
user.
•Accounting. The HPSS accounting system provides the means to collect usage information in
order to allow a particular site to charge its users for the use of HPSS resources. It is the
responsibility of the individual site to sort and use this information for subsequent billing
based on site-specific charging policies. For more information on the HPSS accounting policy,
refer to Section 2.3.7: HPSS Policy Modules on page 47.
2.3.5. HPSS User Interfac es
As indicated in Figure 3, HPSS provides the user with a number of transfer interfaces as discussed
below.
•File Transfer Protocol (FTP). HPSS provides an industry-standard FTP user interface.
Because standard FTP is a serial interface, data sent to a user is received serially. This does
not mean that the data within HPSS is not stored and retrieved in parallel; it means that the
Parallel FTP Daemon within HPSS must consolidate its internal parallel transf ers into a serial
data transfer to the user. HPSS FTP performance in many cases will be limited not by the
speed of a single storage device but by the speed of the data path between the HPSS Parallel
FTP Daemon and the user’s FTP client.
•Parallel FTP (PFTP). The PFTP supports standard FTP commands plus extensions and is
built to optimize performance for storing and retrieving files from HPSS by allowing data to
be transferred in parallel across the network media. The parallel cli ent interfaces have a
syntax similar to FTP but with numerous extensions to allow the user to transfer data to and
from HPSS across parallel communication interfaces established between the PFTP cl ient 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 PFTP client establis hes a
control connection with the HPSS Parallel FTP Daemon and subsequently establishes TCP/IP
data connections directly with HPSS Movers to transfer data at rates limited only by the
underlying media, communications hardware, and software.
•Client Application Program Interface (Client API). The Client API is an HPSS-specifi c
programming interface that mirrors the POSIX.1 specification where possible to provide ease
of use to POSIX application programmers. Additional APIs are also provided to allow the
programmer 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; fil e data and attribute access
operations; file name operations; directory creation, deletion, and access operations; and
working directory operations. HPSS users interested in taking advantage of parallel I/O
capabilities in HPSS can add Client API calls to their applications to uti lize parallel I/O. For
the specific details of this interface see the HPSS Programmer’s Referenc e Guide, Volume 1.
•HPSS VFS Interface. The HPSS VFS Interface presents a standard POSIX I/O interface to a
user application. This obviates the need for a user application to be rewritten against the
HPSS Client API and hence can be used “out of the box” as long as the user application is
POSIX compliant. A portion of an HPSS directory tree can be mounted on a client machine
as if it were a local POSIX-compliant filesystem.
2.3.6. HPSS Management In terfaces
HPSS provides a graphical user interface, the SSM hpssgui, for HPSS administration and operati ons
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