User's Manual UPS control system

A: No, the error is not serious. Unfortunately, the documentation in the
area of master/slaves is not very detailed, and for that reason, your
slave setup is not totally correct as explained below.
On master machines, we modify /etc/rc.d/init.d/halt to re-invoke
apcupsd with the --killpower option (actually the script apccon-
trol is called). This causes the UPS to send the codes to the UPS to
make it power off.
On slave machines, these modifications should not be made to the
/etc/rc.d/init.d/halt script since the slave has no connection to the
UPS.
To eliminate the problem, on all your slave machines, either re-
store the original halt file, or simply delete all the lines containing
***apcupsd***, which were inserted by the apcupsd installation pro-
cess.
Q: To test apcupsd, I unplugged the UPS to simulate a power outage.
After the machine went into the shutdown process I plugged the UPS
back into the commercial power source. This caused the shutdown
process to hang after the daemon tried to shut-off the ups. Have you
run into this problem, and if so do you have a remedy?
A: Normally, once the shutdown process has begun, we cannot stop it,
though there is some code that tries to do so, we don’t consider it a
very good idea – how do you stop a shutdown that has killed off half
of the daemons running on your system? Most likely you will be left
with an unusable system. In addition, when apcupsd is re-executed in
the halt script after the disks are synced, it tries to shut off the UPS
power, but the UPS will generally refuse to do so if the AC power is
on. Since we cannot be 100% sure whether or not the UPS will shut
off the power, we don’t attempt to reboot the system if we detect that
the power is back as it might then get caught by a delayed power off
(at least for Smart UPSes).
Q: After running apcupsd for a while, I get the following error: “Serial
communications with UPS lost.” What is the problem?
A: We use standard Unix serial port read() and write() calls so once a
connection is made, we generally have few problems. However, there
have been reports that APC’s SNMP Management Card can cause
serial port problems. If you have such a card, we suggest that you
remove it and see if the problem goes away. It is also possible that
some other process such as a getty is reading the serial port.
Q: When apcupsd starts, I get the following error: “attach
shmarea: can-
not get shm area: Identifier removed.” What is the problem?
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