Disable a few cores when you want to save power.

If you have a lot of CPU power and working on battery. If you do not need that much of power and would like to rather save some battery power by disabling some cpus then you can use the below script. This script disables cpus from 4 to 7. You can change the number in the for loop. You would need the sudo to be setup or remove sudo and run the script as root. The script will show you the currently active cpu’s before and after disabling the CPU’s.

Battery performance improvement with powertop and using xidel.

For those of you, who have not heard about powertop, it is a tool to monitor the power consumption on your system. It has a tab which shows the tuneable parameters. Doing the changes suggested in those would improve the life to quite an extent. Here is the description of powertop:

PowerTOP is a tool that finds the software component(s) that makeyour computer use more power than necessary while it is idle.

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quick bash script for datewise backup of directory

I was working on something and the data was very critical and needed backup. I wrote a bash script to back up the data every 5 hours with cron and bash script. Thought I will share that with you. Here is the script.

#!/bin/bash - 
#===============================================================================
#
#          FILE:  backup.sh
# 
#         USAGE:  ./backup.sh 
# 
#   DESCRIPTION:  Backup all the current files.
# 
#       OPTIONS:  ---
#  REQUIREMENTS:  ---
#          BUGS:  ---
#         NOTES:  ---
#        AUTHOR: Amit Agarwal (aka), amit.agarwal@roamware.com
#       COMPANY: Roamware India Pvt Ltd
#       CREATED: 08/19/2011 02:43:32 PM IST
#      REVISION:  ---
#===============================================================================
backupf=( a b c d) #Here you need to specify the directory you need to backup.
bkupdir="/tmp/backup/$(date +%Y)/$(date +%m)/$(date +%d)" #Here you can change the basedir for the backups
mkdir  -p $bkupdir
sudo tar cvfz $bkupdir/bkup_$(date "+%Y%m%d_%H%M").tgz $backupf[*] #Remove sudo if you do not need it.
echo "Backup created in dir $dir"

And then just add it to cron as “00 */5 * * * /home//bin/backup.sh”. Change the path if it does not match what is given here.

Shortcut to run current command with sudo in bash

For me, I mostly forget to add “sudo” to the command until the time I am actually supposed to run it. Also sometimes, on some systems, bash completion does not work as expected with “sudo”. With these in mind, I wanted something such that when I have completed the command, I could insert sudo in the begining of the command without much ado. So, finally this is what I came up with in my “~/.inputrc” file. Note: If you don’t have this file, then simply create this file.

Ubuntu – Really force remove a package.

I was trying to remove a package on one of the Ubuntu installations the other day and was not able to do so. I tried google and tried all the options mentioned in various forums like “-f”, purge, reinstall and few others but nothing helped. I kept getting some errors about some files being already deleted. I also tried “set -e” in the prompt but the only result I got was terminal also getting killed.

snmpd -verify if the mibs are loaded.

If you are setting up the snmpd server and have added your own mibs and do not really know if the mibs are loaded or not then simply go to the directory:

/var/lib/net-snmp/mib-indexes

This can save you a lot of time, if you are not getting results with snmpwalk. You can even use snmpwalk as :

snmpwalk -v  -c

Well, these little things can save you a lot of time 🙂

Music players on Linux – the poor mans random song player.

If you have more applications running on your system then your system can handle them then you know what I mean when I say that the Music Players take a lot of CPU. Otherwise harmless, but when you are doing too many things, then lot of times you would feel that probably stopping the Music player might help. But then Linux is all about alternatives. So, there is a command line player called mpg123, which does not use so much CPU. But what about playlist 🙂