VirtualBox – Copy Paste Not working (Debian)

Even though you have set bidirectional for the option Shared Clipboard in settings ( under General –>Advanced ) some times it will not work. The following steps fixed this issue for me.

In the guest OS do the following :

  1. update source.list file
  • enable the contrib repositories; e.g. for Debian 8, make sure your /etc/apt/sources.list contains something like
    deb http://ftp.debian.org/debian jessie main contrib

2.  Install guest addition software.


apt-get update
apt-get install virtualbox-guest-dkms

Error processing package nginx

During the installation of nginx using apt repository ie when we use the following command :
apt-get install nginx we may come across some error messages like this,

Job for nginx.service failed. See ‘systemctl status nginx.service’ and ‘journalctl -xn’ for details.
invoke-rc.d: initscript nginx, action “start” failed.
dpkg: error processing package nginx-full (–configure):
subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of nginx:
nginx depends on nginx-full (>= 1.6.2-5+deb8u4) | nginx-light (>= 1.6.2-5+deb8u4) | nginx-extras (>= 1.6.2-5+deb8u4); however:
Package nginx-full is not configured yet.
Package nginx-light is not installed.
Package nginx-extras is not installed.
nginx depends on nginx-full (<< 1.6.2-5+deb8u4.1~) | nginx-light (<< 1.6.2-5+deb8u4.1~) | nginx-extras (<< 1.6.2-5+deb8u4.1~); however:
Package nginx-full is not configured yet.
Package nginx-light is not installed.
Package nginx-extras is not installed.

dpkg: error processing package nginx (–configure):
dependency problems – leaving unconfigured
Errors were encountered while processing:
nginx-full
nginx
E: Sub-process /usr/bin/dpkg returned an error code (1)

Fix

Stopping the apache service (or current webserver) before we try to install nginx, would solve this issue. Once we get nginx installed, we can start apache service again.

Hence the following steps are supposed to solve this issue.

1. sudo systemctl stop apache2.service
2. sudo apt-get install nginx
3. sudo systemctl start apache2.service

http://localhost:50070 Not Working – Hadoop Issues

Issues — while running a hadoop app

http://localhost:50070 not working

It is commom to get “Page not found” error when you type above link. Generally this is related to name node of the application. To ensure that just type in the command jps in terminal and see if namenode is present in the output. Most proobably it would not be there and that is why you are not able to lauch that url.

Fix

A.      As a soultion to this error, strop all the services either by running stop-all.sh (depreicated) or running stop-dfs.sh and stop-yarn.sh

B.     Then restart hadoop by typing in start-dfs.sh start-yarn.sh

C. Now try executing jps command and see if namenode is there. Ii would be there with all possiblilities. Then try http://localhost:50070 in browser and you would the window.

D. If namenose is still missing on executing jps command even after restrting the entire hadoop system (step C), you would have to do something about the hdfs file system, which has been specified in the previous post. Please go through it if you are interested

HeadPhone port Not working in Ubuntu?

This post is a bit different from what I have posted so far. Because just before switching to every new task, I would take a break and listen to music. Today also I did the same as usual but with only difference  -My headphone port of Laptop was not working. But laptop speaker worked like charm. Everything was fine till yesterday. (I tried different headphone which were working in other laptops).

After a few minutes googling I could fix this issue and go back to my routine . And the fix is as follows.

This issue is related to device driver. Somehow  config file of Alsa driver got overwritten and that needs to be reverted and for which open the terminal and type in:

cd /usr/share/pulseaudio/alsa-mixer/paths/

It would be good if we keep a back up file of the config file we are going to edit and try running the following command for that:

sudo cp analog-output-headphones.conf analog-output-headphones.bak

Next, open the config file  using the command :

sudo gedit analog-output-headphones.conf

Look for the section called [Element Speaker] . For me these two fields were set to “off”.  We need to change the section  “Element Speaker” as below,

[Element Speaker]
switch = on
volume = ignore

Then save thses changes. Restart the computer and  and unplug the headphone and reinsert  it. It will work now. (For me it worked).