modelaje de apagado

1. A power-handling CL program for multiple IBM i servers
Rather than connecting your AS/400's to their own separate UPSs, find out how
one UPS, one cable and a CL program can manage all your power-handling needs.
Steve Pitcher, Contributor
Here is a conundrum for you: three AS/400's, one UPS and one UPS cable. All
systems were already protected by the UPS, but there is only the one cable. This
means that in the event of a power outage, only one AS/400 will shut itself down
before the UPS runs out of battery power. The other two machines, meanwhile,
will run out of power and go down hard. All of the AS/400's need to be notified
in the event of a power loss in order to have each machine shut down.
There was talk at first of splitting the UPS cable three ways and attaching a
split to each AS/400. That idea would most likely work fine, but IBM doesn't
support such a configuration. Another option would be to purchase an additional
two UPS's and independent cables so that each AS/400 would have one . That is
fully supported, but it's a little costly and produces a lot of extra hardware.
The solution I finally came up with was so simple: Connect one UPS data cable to
our primary AS/400 and use remote commands to power down the other machines.
Creating a power-handling program
After a predetermined amount of time on UPS power, we want to notify users on
all systems of an imminent shutdown and bring down all AS/400's in a manner more
graceful than a hard power loss.
The IBM i Information Center provides an example control language (CL) program
for monitoring a message queue allocated exclusively for UPS messages and
powering down the system in a controlled fashion. We can take this code and
customize it to fit our needs.
In addition to creating the program, we will need to change a few system values
and create the message queue to handle UPS-related messages. These steps on
power-handling programs are well-documented.
Within the power-handling program, we need to add a submit remote command
(SBMRMTCMD) to power down each additional IBM i server. In order to send a
remote command to another IBM i, we need to use the CRTDDMF command to set up a
distributed data management (DDM) file on the source server for each target
server. There will also need to be a file on the target servers that each DDM
file will point to and connect.
I'd suggest putting the all of these objects in custom libraries dedicated to
UPS-related activities. On my servers and in the IBM Information Center article,
the library is defined as UPSLIB.
Create your DDM file with this command:
CRTDDMF FILE(UPSLIB/DDM170) RMTFILE(UPSLIB/GETUPSMSG) RMTLOCNAME(sys2 *IP)
In this command, the DDM file (DDM170) is created on the source server in
library UPSLIB. On the target server, I have an existing physical file called
GETUPSMSG in library UPSLIB, which the source DDM file uses to identify what
file to connect to. The rest of the command specifies the remote location name
(sys2) and the method of communication (TCP/IP).
In the execution of my power-handling CL program, I want to send a quick note to
all users on remote systems (a model 170 and a model 270 server) informing them
that they have limited time to log off. I then want to wait several minutes and
power down those systems, as well as the source server.
This code explains how to do this:
/* Notify users on 170 server */

2. SBMRMTCMD CMD('sndbrkmsg msg(Server will be shutting down in 5 minutes due to
power failure.
Log off immediately.) tomsgq(*allws)') DDMFILE(upslib/ddm170)
/* Notify users on 270 server */
SBMRMTCMD CMD('sndbrkmsg msg(Server will be shutting down in 5 minutes due to
power failure.
Log off immediately.) tomsgq(*allws)') DDMFILE(upslib/ddm270)
/* Notify users on this 515 server */
SNDBRKMSG MSG(Server will be shutting down in 5 minutes due to power failure.
Log off immediately.) TOMSGQ(*allws)
DLYJOB DLY(300)
/* Power down 170 server */
SBMRMTCMD CMD('pwrdwnsys option(*immed)') DDMFILE(upslib/ddm170)
/* Power down 270 server */
SBMRMTCMD CMD('pwrdwnsys option(*immed)') DDMFILE(upslib/ddm270)
/* Power down this 515 server */
PWRDWNSYS OPTION(*IMMED)
It's simple code with a powerful result. Using remote commands can be very
useful in other ways as well, including running queries on a target IBM i and
pulling the returned data back to the source IBM i.
ABOUT THE AUTHOR: Steve Pitcher is the Enterprise Servers and Application
Analyst for Minas Basin Pulp & Power in NS, Canada. He's been specializing in
System i and Lotus Domino solutions for the last decade. His blog, ENDJOBABN
covers his adventures in, and amusement with, his work on the IBM i and Lotus
Domino.