Set gnome-shell to start in fallback mode without GUI.

If you run into issues with gnome-shell then gnome-shell should allow you to disable all the plugins and get the gnome-shell. But since gnome-shell is still evolving, you might run into issue where the shell does not come up. What to do in that case. You can set the shell to start in fallback mode, where there are more chances that it will come up.

Alas, but you don’t have a shell or desktop session to do that. Simple, start the gnome-shell and before it is killed, do this:

Color disk usage on Fedora

For this tip, you would need to setup the rpm-shere repository. You can get the information here. Once you have done that you need to install the cdu package with the following command:

sudo yum install cdu

And then you can use “cdu” to view the disk usage in all beautiful colors with the command:

cdu

and the output looks like this:

[][2]

Related articles

• Quickly install most of the things that you need on Fedora. (amit-agarwal.co.in)
• Upgrading Fedora using yum – FedoraProject (fedoraproject.org)
• Consistent ethernet device names in Verne (amit-agarwal.co.in)

Interesting repository for Fedora.

Here is one repository that you can add to your Fedora to give it a few more hundred packages:

cat >/etc/yum.repos.d/rpm-sphere.repo <<EOF
[rpm-sphere]
name=RPM Sphere
baseurl=http://download.opensuse.org/repositories/home:/zhonghuaren/Fedora_16/
gpgkey=http://download.opensuse.org/repositories/home:/zhonghuaren/Fedora_16/repodata/repomd.xml.key
enabled=1
gpgcheck=1
EOF

Benchmarking the system/CPU performance

Have you ever wanted to have a quick check on your CPU performance. I know that lot of people will say that this is not the right way to do this, but here is something that you can use to check the CPU speed.

#!/bin/bash -
#===============================================================================
#
#          FILE:  benchmark.sh
#
#         USAGE:  ./benchmark.sh
#
#   DESCRIPTION:  Benchmark the CPU
#
#       OPTIONS:  ---
#  REQUIREMENTS:  ---
#          BUGS:  ---
#         NOTES:  ---
#        AUTHOR: Amit Agarwal (aka), amit.agarwal@roamware.com
#       COMPANY: Roamware India Pvt Ltd
#       CREATED: 09/21/2011 11:46:03 AM IST
# Last modified: Wed Sep 21, 2011  12:22PM
#      REVISION:  ---
#===============================================================================

add ()
{
    COUNTER=0
    exec 2>&1
    time=$(exec 2>&1;(time while [[  $COUNTER -lt 100000 ]]; do ((COUNTER++)) \
        ; done))
    echo "Time for 100000 additions is "$time
}	# ----------  end of function add  ----------
mul ()
{
    COUNTER=0
    test=2
    exec 2>&1
    time=$(exec 2>&1;(time while [[  $COUNTER -lt 100000 ]]; do ((COUNTER++)) \
        ; ((test=test*2));done))
    echo "Time for 100000 mul is "$time
}	# ----------  end of function add  ----------
div ()
{
    COUNTER=0
    test=1000000000000
    exec 2>&1
    time=$(exec 2>&1;(time while [[  $COUNTER -lt 100000 ]]; do ((COUNTER++)) \
        ; (( test=test/2)); done)|tr -d '\n')
    echo "Time for 100000 divisions is "${time}
}	# ----------  end of function add  ----------

time add
time mul
time div

And here is the output :

conky script used to monitor server status remotely.

[][1]

I was looking for something to monitor few details on the server. I thought about quite a lot of applications, some open source and some scripts developed in house. But my requirements were quite petty and the scripts and applications were quite heavy. So, I thought why not conky :).

So, with some quick work on conky script, I was able to get what I wanted and here it is for all of you.

BASH Script Performace

Today we will look at some bash code snippests and the performance issues. Lets first look at the problem and the implemented solution:

Problem: We needed to log the output of the ps command for all the process’s. This was required to be done on per minute basis and the output was required in comma separated files. So, here is what was implemented:

pslog=`ps -e -opid,ppid,user,nlwp,pmem,vsz,rss,s,time,stime,pri,nice,pcp:u,args|grep -v PID|sort -r -k 13,13`
        OLD_IFS=$IFS
        IFS=$'\n'
        logarr=( $pslog )
        for LOGLINE in ${logarr[@]}
        do
                LOGLINE=`echo $LOGLINE|awk '{OFS=",";print $1,$2,$3,$4,$5,$6,$7,:$8,$9,$10,$11,$12,$13,$14}'`
                echo $LOGLINE >> output
        done
        IFS=$OLD_IFS

This was working well and there were no issues. But suddenly we started seeing issues with the reported CPU usages. We would see that whenever this script was running the CPU usage was high, specially if there were too many process’s/thread’s on the system during that time.  This code was definitely part of a very large code base, and at this point of time we did not know what was causing the issues.

Happy New Year 2012

Happy new year to all.