Sometimes you need to keep OpenVMS hosts from overloading a SAN storage controller fibre channel port. The SANCP utility, new in V8.3, allows you to limit the number of I/O requests “in flight” to that fibre channel port on the SAN storage controller. This is often needed in “Tier 1″ storage environments, which share resources across numerous hosts. The SANCP utility allows you to set the WTID cap. That acronymn stands for the World-wide id Thottle I/o Descriptor.
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HP OpenVMS Version 8.3 New Features and
Documentation Overview
3.11 SANCP Utility

The SANCP utility allows you to limit the number of active I/Os a host
may have across all paths to Logical Unit Numbers (LUN) on a given
Fibre Channel storage port. A storage port can be selected by a
discrete or wildcarded port World Wide ID (WWID) or by a product ID
substring.

The SANCP utility processes a command and qualifiers passed to it on
the command line, allowing it to be executed from a DCL script, or it
prompts you if started with no command. For more information about the
SANCP utility, see the SANCP Help facility.

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RMS Tuning Cycle

This clip shows a brief overview of the RMS (Record Management System) tuning cycle. This essentially allows the users to gather information as they use the RMS file. Then based on the information gathered from the file, the RMS file user can adjust the tuning of the RMS parameters and generate a more effective RMS file structure.
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HP OpenVMS Systems Documentation
Guide to OpenVMS File Applications
Figure 10-8 RMS Tuning Cycle

Figure 10-7 Structure of Alternate Records

Example 10-7 shows an examination of an alternate record.

You can use the Analyze/RMS_File utility to create an FDL file
generally called an analysis file. FDL files created by
ANALYZE/RMS_FILE contain statistics about each area and key in the
primary sections named ANALYSIS_OF_AREA and ANALYSIS_OF_KEY.

These analysis sections are then used by the Edit/FDL utility in its
Optimize script. You can compare the statistics in these sections with
your assumptions about the file’s use; you may find some places in the
file’s structure where additional tuning will be possible.

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The OpenVMS Freeware V5.0 set contains the [RMS_TOOLS] directory where Hein van den Heuvel placed his RMS_TUNE_CHECK utility. This is a quick pointer to that tool.
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OpenVMS Freeware Abstracts
Abstracts for Volume DISK$FREEWARE50_2
[RMS_TOOLS] Miscellaneous RMS Tools

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T4 & Friends

This OpenVMS Technical Journal article by Steve Lieman describes how using T4 & Friends can allow a system manager to better understand the interactions of the various OpenVMS “service centers” over time. This allows better insight into those interactions and better control over the testing of methods to improve performance.
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HP OpenVMS Systems
OpenVMS Technical Journal

TimeLine-Driven Collaboration with “T4 & Friends”: A Time-saving Approach to OpenVMS Performance

Steve Lieman Performance Group,
OpenVMS Engineering, Nashua, NH, USA

This OpenVMS Technical Journal
article gives you the background story on TimeLine Collaboration (TLC), sketches the universal
ingredients of a timeline-driven approach to OpenVMS performance, highlights
the original and the current capabilities of the “upstream” and “downstream” Friends of T4, and details the central
role played by growing reservoirs of TimeLine Collaboration format data.

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In this OpenVMS Technical Journal article, Gorazd Kikelj discusses how to add an RMS performance statistics collector to the normal T4 & Friends data collection. This has several advantages over other techniques, which will be show in other blog entries.
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HP OpenVMS Systems
OpenVMS Technical Journal V11

RMS Collector for T4 and Friends

Gorazd Kikelj, HP Account Support Manager

Overview

This article
provides a technique of expanding T4 and Friends with additional data
collectors and with minimal impact to the core T4 procedures and utilizing
services provided by them. The example described is uses a MONITOR RMS
extension to monitor RMS file statistics.

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Known as Secondary Index Data Record (SIDR) chains, RMS indexed files can increase system overhead without the developer or system manager being aware of this issue. In this VMS Technical Journal article, Hein van den Heuvel discusses this issue an methods to address the problem.
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HP OpenVMS Systems

RMS Performance: Duplicate key chains

Hein van den Heuvel

Overview

Does
your application use RMS Indexed files?
Do you know what a SIDR is? Do you know what a duplicate key chain is?
You probably should, since SIDRs and duplicate key chains can cause thousands
of read I/Os as the result of a single record insert. With that, they can have
a tremendous impact not just on the application doing the insert, but also on
total system performance. Application managers, of course, notice
a slowdown over time, and all too often they solve that by throwing more
hardware at the problem. But what if you already have the biggest box on the
market? Modest file tuning and a convert can help avoid all those read I/Os and
restore performance. I have yet to investigate an RMS application that did not
have this duplicate key chain problem. Maybe this is because I get called in
only for bad cases, or because indeed so many applications have this problem,
at least to some degree.

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