Hpss Interface Considerations; Client Api; Ftp; Table 4. Paging Space Info - IBM High Performance Storage System HPSS Installation Manual

The amount of memory for nodes running HPSS Movers, and no DB2 servers, is dependent on the
number and types of devices configured on the Mover node, the expected usages of those devices,
and the configuration of the Movers
memory than Movers supporting tape devices because disk devices are likely to have more
outstanding requests. At least 1GB of memory should be configured on the Mover nodes. More
memory is required for nodes that support many devices, especially disks, and have large numbers of
concurrent end-user requests. Additionally, the size of the Mover's internal buffers impacts the
Mover's memory requirements. Two buffers are used by each Mover process to handle I/O requests.
Paging space should be sized according to the following rules:
Amount of physical memory
memory <= 256MB
256MB < memory <= 1GB
1GB < memory <= 2GB
2GB < memory

3.6. HPSS Interface Considerations

This section describes the user interfaces to HPSS and the various considerations that may impact the
use and operation of HPSS.

3.6.1. Client API

The HPSS Client API provides a set of routines that allow clients to access the functions offered by
HPSS. The API consists of a set of calls that are comparable to the file input/output interfaces
defined by the POSIX standard (specifically ISO/IEC 9945-1:1990 or IEEE Standard 1003.1-1990),
as well as extensions provided to allow access to the extended capabilities offered by HPSS.
The Client API is built on top of the HPSS security layer (either UNIX or Kerberos). It must be run
on a platform that supports the Core Server's security layer. For example if the Core Server is using
Kerberos authentication then users on the client platform must be able to authenticate themselves
with the Core Server's Kerberos realm. To access HPSS from client platforms that do not support the
Core Server's security layer, FTP or Parallel FTP must be used.
The Client API allows clients to specify the amount of data to be transferred with each request. The
amount requested can have a considerable impact on system performance and the amount of metadata
generated when writing directly to a tape storage class. See Section 3.9.6: Location Policy on page 99
and Section 3.11: HPSS Performance Considerations on page 112 for further information.
The details of the Application Program Interface are described in the HPSS Programmer's Reference
Guide.

3.6.2. FTP

HPSS provides an FTP daemon that supports standard FTP clients. Extensions are also provided to
allow additional features of HPSS to be utilized and queried. Extensions are provided for specifying
Class of Service to be used for newly created files, as well as directory listing options to display
HPSS Installation Guide
Release 6.2 (Revision 2.0)
In general, Movers supporting disk devices will require more
.

Table 4. Paging Space Info

Minimum recommended amount of paging space
2 * amount of physical memory
512MB + ((amount of physical memory – 256MB) * 1.25)
1.5 * amount of physical memory
1 * amount of physical memory
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