Specifications
24 Optimizing IBM Netfinity Servers for SAP R/3 and Windows NT
External Disk Subsystems
If possible always connect external disk subsystems to the same UPS system as
the server where their data cables are connected to. If they are connected to
different UPS systems and only the UPS system with the connected external disk
subsystem loses utility power and shuts down after the battery is exhausted, you
may lose data and/or your operating system will hang because your server is still
running and your external disk subsystem is powered off without the operating
system shutdown procedure.
But if you use mirrored external disk subsystems and one unit is the exact mirror
of the other, then connect one external subsystem along with the server to one
UPS system and the other subsystem can be installed to the same or, for better
availability, to another UPS system.
Another configuration is a clustered server environment. If two servers share one
external disk subsystem, then either connect all servers and subsystems to the
same UPS system or connect the two servers to different UPS systems and try to
share the power for the external disk subsystem between the two UPSs. For
example the IBM Netfinity EXP10 Storage Expansion Unit has two redundant
power supplies and each one of them has its own power connector. Each of the
two power supplies can now be connected to a different UPS systems.
2.2.3.3 The APC PowerChute plus Software
This book does not cover a complete installation of the PowerChute
plus
software. You may find details about configuration and installation in the APC
PowerChute
plus
installation and user guides. You can find these manuals in
Acrobat Reader format (PDF) on the ServerGuide Application CD-ROM 3A. The
following files are located in the directory \Pwrchute\En\NTnoext\Docs:
• RELNOTES.PDF -- PowerChute
plus
Release Notes for Windows NT
• INSTALL.PDF -- PowerChute
plus
5.0 Installation Guide for Windows NT
• MANUAL.PDF -- PowerChute
plus
5.0 User's Guide for Windows NT
Here are some considerations you should take into account before you install and
set up the UPS software.
The PowerChute
plus
for Windows NT software comprises three modules that
can be installed:
1. The monitoring service
ups.exe
This module is a Windows NT service and communicates with the UPS over
the RS232 interfaces on the server and the UPS. The monitoring service logs
data and events, notifies users of impending shutdowns, and when necessary,
shuts down the server. To run this module the server has to be connected to a
UPS over an RS232 link.
2. The graphical user interface program
pwrchute.exe
.
You can control and configure the PowerChute plus program and monitor the
UPS with it. You will get access to real-time data from a local monitoring
service or over the network from remote installed monitoring services on other
servers that are connected to a UPS.
3. Online help in HTML format.