Sponsored Content
Full Discussion: Wrong Array...
The Lounge War Stories Wrong Array... Post 303026919 by bakunin on Wednesday 5th of December 2018 06:57:18 AM
Old 12-05-2018
Here is my personal "power-loss-story" and it has nothing to do with a power-button:

Back around 2000 i was working for a data center, which - nothing really unusual - had a large ~1000hp diesel generator to back up its UPS. This diesel was tested every year once by switching it on for 2 minutes. Everything worked fine.

Now, what happens if you run such a system for two minutes a year? Disaster struck and showed to the responsible people exactly what happens in such a case: during a heavy thunderstorm the nearby transformer station (or, specifically, its large 6m-diameter capacitor was hit by a lightning. The whole area was suddenly without electrical current and the remains of the capacitor lay across half of the street in pieces not bigger than a few centimeters each.

First, our UPS kicked in - as planned. Then, when the UPS batteries went low, the diesel started. It ran for about 5-6 minutes, then stuck with a piston seizure because running keeps such a machine lubed. When it doesn't run all the bearings eventually run dry of oil. So far, so bad and our data center stood without electrical power.

What makes the story interesting, though, is: at the same time adear friend of mine (shockneck) worked for another data center across the street. So, two days after the incident, we sat in a cafe commiserating about life as an admin. And he told me, they had a UPS, backed by a diesel. And because they knew that engines have to run every now and then to remain properly lubed they switched it on every month and let it run for 10 minutes. Alas, their diesel gave up a few minutes after starting. You know, when letting it run so often you need to refill the tank now and then.....

bakunin
These 4 Users Gave Thanks to bakunin For This Post:
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

create array holding characters from sring then echo array.

Hi, I wish to store $string1 in $string1array a character in each array element. Then i wish to echo the entire array to the screen so that it reads as the normal string again. I have been trying with the code below but does not work. Please help... To put string into array: ... (5 Replies)
Discussion started by: rorey_breaker
5 Replies

2. Programming

Creating an array to hold posix thread ids: Only dynamic array works

I am facing a strange error while creating posix threads: Given below are two snippets of code, the first one works whereas the second one gives a garbage value in the output. Snippet 1 This works: -------------- int *threadids; threadids = (int *) malloc (num_threads * sizeof(int)); ... (4 Replies)
Discussion started by: kmehta
4 Replies

3. Shell Programming and Scripting

PHP: Search Multi-Dimensional(nested) array and export values of currenly worked on array.

Hi All, I'm writing a nagios check that will see if our ldap servers are in sync... I got the status data into a nested array, I would like to search key of each array and if "OK" is NOT present, echo other key=>values in the current array to a variable so...eg...let take the single array... (1 Reply)
Discussion started by: zeekblack
1 Replies

4. Shell Programming and Scripting

perl, put one array into many array when field is equal to sth

Hi Everyone, #!/usr/bin/perl use strict; use warnings; my @test=("a;b;qqq;c;d","a;b;ggg;c;d","a;b;qqq;c;d"); would like to split the @test array into two array: @test1=(("a;b;qqq;c;d","a;b;qqq;c;d"); and @test2=("a;b;ggg;c;d"); means search for 3rd filed. Thanks find the... (0 Replies)
Discussion started by: jimmy_y
0 Replies

5. Shell Programming and Scripting

Store all the passed arguments in an array and display the array

Hi I want to write a script which store all the parameters passed to the script into an array. Once it is stored I want scan through the array and and delete those files for last month present inside the directory. The files in directory is appneded with YYYY_MM_DD. I want to know how can I... (3 Replies)
Discussion started by: dgmm
3 Replies

6. Shell Programming and Scripting

Array in Perl - Detect several file to be in one array

Hi everyone I have one question about using array in perl. let say I have several log file in one folder.. example test1.log test2.log test3.log and the list goes on.. how to make an array for this file? It suppose to detect log file in the current directory and all the log file will... (3 Replies)
Discussion started by: sayachop
3 Replies

7. Shell Programming and Scripting

PERL : Read an array and write to another array with intial string pattern checks

I have an array and two variables as below, I need to check if $datevar is present in $filename. If so, i need to replace $filename with the values in the array. I need the output inside an ARRAY How can this be done. Any help will be appreciated. Thanks in advance. (2 Replies)
Discussion started by: irudayaraj
2 Replies

8. Shell Programming and Scripting

Why result is wrong here ? whether break statement is wrong ?

Hi ! all I am just trying to check range in my datafile pls tell me why its resulting wrong admin@IEEE:~/Desktop$ cat test.txt 0 28.4 5 28.4 10 28.4 15 28.5 20 28.5 25 28.6 30 28.6 35 28.7 40 28.7 45 28.7 50 28.8 55 28.8 60 28.8 65 28.1... (2 Replies)
Discussion started by: Akshay Hegde
2 Replies

9. Shell Programming and Scripting

Bash 3.2 - Array / Regex - IF 3rd member in array ends in 5 digits then do somthing...

Trying to do some control flow parsing based on the index postion of an array member. Here is the pseudo code I am trying to write in (preferably in pure bash) where possible. I am thinking regex with do the trick, but need a little help. pesudo code if == ENDSINFIVEINTS ]]; then do... (4 Replies)
Discussion started by: briandanielz
4 Replies

10. Shell Programming and Scripting

Bash arrays: rebin/interpolate smaller array to large array

hello, i need a bit of help on how to do this effectively in bash without a lot of extra looping or massive switch/case i have a long array of M elements and a short array of N elements, so M > N always. M is not a multiple of N. for case 1, I want to stretch N to fit M arrayHuge H = (... (2 Replies)
Discussion started by: f77hack
2 Replies
CLONE(8)							    NUT Manual								  CLONE(8)

NAME
clone - UPS driver clone NOTE
This man page only documents the specific features of the clone driver. For information about the core driver, see nutupsdrv(8). DESCRIPTION
This driver, which sits on top of another driver socket, allows users to group clients to a particular outlet of a device and deal with this output as if it was a normal UPS. EXTRA ARGUMENTS
This driver supports the following settings: load.off=command Recommended. Set the command on the "real" UPS driver that will be used to switch off the outlet. You need both load.off and load.on in order to power cycle the outlet. Otherwise, shutting down the clients powered by an outlet is a one way street (see IMPORTANT). load.on=command Recommended. Set the command on the "real" UPS driver that will be used to switch on the outlet. You need both load.off and load.on in order to power cycle the outlet. Otherwise, shutting down the clients powered by an outlet is a one way street (see IMPORTANT). load.status=value Recommended. Set the variable on the "real" UPS driver that will be used to indicate the outlet status (i.e. on/off). If not specified, the clone driver will attempt to keep track of the outlet status, but this is less reliable. offdelay=num Set the timer (in seconds) before the outlet is turned off after the shutdown condition (OB LB) for this outlet is met or a command to shutdown was issued. Defaults to 120 seconds. ondelay=num Set the timer (in seconds) for the outlet to switch on in case the power returns after the oulet has been switched off. Defaults to 30 seconds. mincharge=value Set the remaining battery level when the clone UPS switches to LB (percent). minruntime=value Set the remaining battery runtime when the clone UPS switches to LB (seconds). IMPLEMENTATION
The port specification in the ups.conf(5) reference the driver socket that the "real" UPS driver is using. For example: [realups] driver = usbhid-ups port = auto [clone-outlet-1] driver = clone port = usbhid-ups-realups load.on = outlet.1.load.on load.off = outlet.1.load.off load.status = outlet.1.status [...] IMPORTANT
Unlike a real UPS, you should not configure a upsmon master for this driver. When a upsmon master sees the OB LB flags and tells the upsd server it is OK to initiate the shutdown sequence, the server will latch the FSD status and it will not be possible to restart the systems connected without restarting the upsd server. This will be a problem if the power returns after the clone UPS initiated the shutdown sequence on it's outlet, but returns before the real UPS begins shutting down. The solution is in the clone driver, that will insert the FSD flag if needed without the help of a upsmon master. CAVEATS
The clone UPS will follow the status on the real UPS driver. You can only make the clone UPS shutdown earlier than the real UPS driver, not later. If the real UPS driver initiates a shutdown, the clone UPS driver will immediately follow. Be aware that the commands to shutdown/restart an outlet on the real UPS drivers are not affected, so if you tell the real UPS driver to shutdown the outlet of the clone UPS driver, your clients will lose power without warning. AUTHOR
Arjen de Korte <adkorte-guest@alioth.debian.org> SEE ALSO
upscmd(1), upsrw(1), ups.conf(5), nutupsdrv(8) Internet Resources: The NUT (Network UPS Tools) home page: http://www.networkupstools.org/ Network UPS Tools 05/21/2012 CLONE(8)
All times are GMT -4. The time now is 10:39 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy