how to set up vnstat - a lightweight network bandwidth monitoring tool

vnstat is a network bandwidth monitoring application. it uses data collected by the kernel and so is quite light on the system.

the installation is dependent on your OS but once done, the program requires a little bit more to complete the setup:

this command will create databases to record the bandwidth for all interfaces on the system

for int in `vnstat --iflist| sed 's/Available interfaces://'` 
        vnstat -u -i $int

this next command is needed to allow vnstat to write to the db that was created as root

how to step through a shell script

so you wrote a shell script, likely in bash, and it is pretty long and now you need to step through it. here is how:

at the top of your shell script under your hash bang line and before your code you add these 2 lines

set -x
trap read debug

how to install openstack on centos or fedora or rhel systems

openstack is a cloud system. it has many components. absolutely complicated to install and even worse to get it working just right. until about a week agonow. it is simplified to the following steps

  1. fresh baremetal install of the os on hardware
  2. install the repo
  3. install the software that will install openstack
  4. run the software to install openstack

so what is it? its packstack available at

how to: gain some battery time on your laptop

so you have a laptop and you arent happy with the amount of time the laptop's battery gives you. the solution is a program called powertop that was originally written by some guys at intel. its home page is currently at .

unlike the version 1 series , the version 2 series doesnt tell you how to implement the powersaving tips at bootup via the ui, only interactively toggling betwen good and bad.

so the solution is to run powertop from the command line:

how to: create your own openstack spacewalk channel

there is nothing to it. just 2 simple commands

these 2 commands will first create the channel then inject the packages and their dependencies into the newly created channel. and the commands are ..

How To Upgrade From Fedora 17 To Fedora 18 (Desktop & Server)

ok i did it

i upgraded from fc17 to fc18. it works. its basically 3 steps

  1. fedup --network 18
  2. reboot into the upgrade bootup
  3. yum distro-sync --skip-broken

not many sources out there. i only found this one and it is about fedup

note that i havent yet discovered where the cache for fedup is yet, so if you know leave me a comment

howto: satellite configuration and channel population

this how to is intended to configure spacewalk, the rhn satellite's upstream project as well as to create channels and populate it. the end result is a spacewalk server with channels that is intended to use internally as the password and channel keys are very lax.step 1 starts after you have installed spacewalk. instructions are here.

how to install drush5.7 on centos6.3

everything is pretty simple when you know how. the problem only occurs when you dont know how. well with this howto, you will know how to install drush5.7 onto a centos6.3 box

yum -y install php-pear
pear upgrade
pear channel-discover
pear install drush/drush

nothing to it. i wont tell you about the one hour i spent searching for it.

howto install moodle2.3 on centos6.3

it is apparently pretty simple when you have the key

how to mount an iso from fstab

so to mount an iso from the command line you would use the command

mount -oloop /root/CentOS-6.2-x86_64-bin-DVD1.iso /var/www/html/repo/CentOS-6.2-x86_64/

but if you wanted that to be mounted at boot time via your fstab. it is different

you would have to edit your fstab and add in a line similar to :

/root/CentOS-6.2-x86_64-bin-DVD1.iso /var/www/html/repo/CentOS-6.2-x86_64/ iso9660 loop,ro,auto 0 0

and then issue the command

mount -a

and finally verify with



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