A J's questions

When I tried to create new application in Android Studio I am got a problem in my layout page, design part getting the following error.

Rendering Problems 
Android Nougat requires the IDE to be running with Java 1.8 or later

API24 selected automatically when opened it. And its working fine, when I select API23 manually.

The problem is I have already installed JDK 1.8 in my system and when open Project Structure it's shows correct directory of my JDK 1.8 path as shown below,

I am using Ubuntu 16.04 to run Android Studio, and when I check Java version am getting version as 1.8,

arul@arul-pc:~$ java -version
java version "1.8.0_77"
Java(TM) SE Runtime Environment (build 1.8.0_77-b03)
Java HotSpot(TM) 64-Bit Server VM (build 25.77-b03, mixed mode)

How to solve this ?

I have installed kubuntu 14.04.3 in my laptop, when I check the version of kde its shows as follows,

When I tried sudo add-apt-repository ppa:neon/kf5 in terminal, am getting response as,

Cannot add PPA: 'ppa:neon/kf5'.
Please check that the PPA name or format is correct.

I wish to update kde into Plasma 5. How to solve it ?

To install Cloud Manager successfully in my system (14.04/64b), I shared my localhost ip 127.0.0.1 to my system account.

I edit my host(arul-pc) ip in /etc/hosts/ from 127.0.1.1 to 127.0.0.1 as shown below,

arul@arul-pc:~$ sudo nano /etc/hosts

127.0.0.1       localhost
127.0.0.1       arul-pc

# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

Now when I get host name for 127.0.0.1, it returns arul-pc. I want to make localhost as first match for mentioned ip(127.0.0.1).

How to do it ?

I have downloaded apache-tomcat-7.0.65.tar.gz from here.

I extracted, and started using startup.sh as follows

arul@arul-pc:~$ chmod +x /usr/local/apache-tomcat-7.0.65/bin/startup.sh 
arul@arul-pc:~$ cd /usr/local/apache-tomcat-7.0.65/bin/
arul@arul-pc:/usr/local/apache-tomcat-7.0.65/bin$ ./startup.sh 
Using CATALINA_BASE:   /usr/local/apache-tomcat-7.0.65
Using CATALINA_HOME:   /usr/local/apache-tomcat-7.0.65
Using CATALINA_TMPDIR: /usr/local/apache-tomcat-7.0.65/temp
Using JRE_HOME:        /usr/bin
Using CLASSPATH:       /usr/local/apache-tomcat-   7.0.65/bin/bootstrap.jar:/usr/local/apache-tomcat-7.0.65/bin/tomcat-juli.jar
Tomcat started.
arul@arul-pc:/usr/local/apache-tomcat-7.0.65/bin$

But, when I tried to open in browser using http://localhost:8080/ am getting an error connection refused.

How to solve this?

EDIT 1:

Result, for ps -ef | grep java

arul@arul-pc:~$ ps -ef | grep java
arul      4404  4373  0 11:04 pts/2    00:00:00 grep --color=auto java

EDIT 2:

Results,

arul@arul-pc:~$ which java
/usr/bin/java
arul@arul-pc:~$ java -version
java version "1.8.0_66"
Java(TM) SE Runtime Environment (build 1.8.0_66-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.66-b17, mixed mode)
arul@arul-pc:~$ cd /usr/local/apache-tomcat-7.0.65/logs/
arul@arul-pc:/usr/local/apache-tomcat-7.0.65/logs$ ls
catalina.out
arul@arul-pc:/usr/local/apache-tomcat-7.0.65/logs$

And when I open catalina.out,

I am using Ubuntu 14.04 LTS, and for installing Hadoop I created hadoop user as hduser. When I try to open ~/.bashrc using gedit am getting an error as follows,

hduser@arul-java ~ $ gedit ~/.bashrc

(gedit:9254): Gtk-WARNING **: cannot open display: 
hduser@arul-java ~ $ 

How to solve it ?

I am using Netbeans IDE 8.0 in my system 14.04 LTS.

I have installed Python plugin in Netbeans 8.0 by following this link.

And also I have download python-3.4.1.tgz from this link and installed it as following in terminal,

tar -xvf Python-3.4.1.tgz
cd Python-3.4.1/
./configure
make
sudo make install
./python

I got result at last as,

arul@arul-Aspire-5740:~/Python-3.4.1$ ./python
Python 3.4.1 (default, Sep 19 2014, 17:14:45) 
[GCC 4.8.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> 

I confirmed by using following command in terminal

python3 -V

got response as,

Python 3.4.1

But when I click Auto Detect in Python Platform Manager (Netbeans IDE 8.0.1) am am not getting 3.4.1 in the list(Shown below).

How to solve it ?

UPDATE 1

I tried,

 arul@arul-Aspire-5740:~$ sudo find / -type f -executable -iname 'python*' -exec file -i '{}' \; | awk -F: '/x-executable; charset=binary/ {print $1}' | xargs readlink -f | sort -u | xargs -I % sh -c 'echo -n "%: "; % -V'

And I got result as,

[sudo] password for arul: 
/home/arul/Python-3.4.1/python: Python 3.4.1
/usr/bin/python2.7: Python 2.7.6
/usr/bin/python3.4: Python 3.4.0
/usr/bin/python3.4m: Python 3.4.0
/usr/local/bin/python3.4: Python 3.4.1
/usr/local/bin/python3.4m: Python 3.4.1

It's showing 3.4.1 but why not Netbeans detecting?

I am using Ubuntu 14.04 LTS desktop version, I would like to use Ubuntu 14.04 Server.

Is it possible to migrate (change) from Ubuntu desktop to Ubuntu server without losing data from my system?

I have installed and executed an mapreduce program successfully in my system(Ubuntu 14.04).

I can see the output file as,

hadoopuser@arul-PC:/usr/local/hadoop$ bin/hadoop dfs -ls /user/hadoopuser/MapReduceSample-output
Found 3 items
-rw-r--r--   1 hadoopuser supergroup          0 2014-07-09 16:10 /user/hadoopuser/MapReduceSample-output/_SUCCESS
drwxr-xr-x   - hadoopuser supergroup          0 2014-07-09 16:10 /user/hadoopuser/MapReduceSample-output/_logs
-rw-r--r--   1 hadoopuser supergroup     880838 2014-07-09 16:10 /user/hadoopuser/MapReduceSample-output/part-00000

And I can open it on terminal using following command,

hadoopuser@arul-PC:/usr/local/hadoop$ bin/hadoop dfs -cat /user/hadoopuser/MapReduceSample-output/part-00000

I can see the output file on terminal, but I can't see the full result because my output has large amount of lines.

UPDATION

I have tried to copy the output file into local machine,

hadoopuser@avvenire-PC:/usr/local/hadoop$ bin/hadoop dfs -copyToLocal  /user/hadoopuser/MapReduceSample-output/part-00000 /home/arul/Downloads/SampleDataHadoop

I got response as,

copyToLocal: Permission denied

Expecting solution.

I have installed Ubuntu 14.04 alongside windows 7 by selecting 30GB approximately. Now I want to increase storage memory with out affecting both Ubuntu and Windows.

I saw this question, but I can't find solution in there.

When I do,

arul@ARUL-PC:~$ sudo fdisk -l

I got response,

Disk /dev/sda: 320.1 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x283091b8

Device Boot      Start         End      Blocks   Id  System
/dev/sda1            2048   102606847    51302400    7  HPFS/NTFS/exFAT
/dev/sda2   *   102606848   307199999   102296576    7  HPFS/NTFS/exFAT
/dev/sda3       307204094   625139711   158967809    f  W95 Ext'd (LBA)
/dev/sda5       307204096   389933567    41364736    7  HPFS/NTFS/exFAT
/dev/sda6       449028096   512002047    31486976    7  HPFS/NTFS/exFAT
/dev/sda7       512006144   625139711    56566784    7  HPFS/NTFS/exFAT
/dev/sda8       389935104   443273215    26669056   83  Linux
/dev/sda9       443275264   449015807     2870272   82  Linux swap / Solaris

Partition table entries are not in disk order

Please provide some solutions.

I have installed youtube-dl in my 14.04.

I can download video by following command,

$ youtube-dl [youtube-link]

But I want to know how to select available pixel quality of youtube video(i.e 1080p, 720p, 480p, etc).

In software description they said it's possible(shown in image below), but how to do..

I am using 14.04 for last few months, now it's showing an unknown error in the notification area, as shown in the below Image...

When I click there am getting message as,

The updated information is outdated. This may be cause by network problems or by a repository that is no longer available. Please update manually by selecting "Show updates" from indicator menu, and watching for failing repositories.

But when I click Show updates, am getting as The software on this computer is up to date(see the image below)

How to solve it ?

I have installed Eclipse as following:

1 → Download eclipse-standard-kepler-SR2-linux-gtk-x86_64.tar.gz to my 14.04

2 → Extracted it using the command,

sudo tar -xvf eclipse-standard-kepler-SR2-linux-gtk-x86_64.tar.gz

3 → Moved eclipse to /opt/ using command,

sudo mv eclipse /opt/

4 → Created Icon(64x64) for eclipse using GIMP Image Editor.

5 → Installed gnome-panel using,

sudo apt-get install --no-install-recommends gnome-panel

6 → And Create Application by using,

sudo gnome-desktop-item-edit /usr/share/applications/ --create-new

7 → Select Icon,

8 → Select eclipse application for comment,

9 → Finally enter command and click OK.

I have given everything required, and the application created and showing,

But when I open this application it's not working.

(Note: I have created another one, because first one not worked, and now both not working. That why picture showing two eclipse.)

When I tried to open it in terminal, I got

bash: /opt/eclipse/eclipse: cannot execute binary file: Exec format error

Please tell me where the problem may occur ?

I have installed Hadoop-2.4.0 in my system(14.04), I want to remove it completely and reinstall it. If I have delete the configured folder hadoop, is it enough to remove hadoop in my Ubuntu 14.04 LTS.

I have installed and configured spammassassin in my system(14.04) using this tutor. When I start a service using,

service spamassassin start

am getting response as,

Starting SpamAssassin Mail Filter Daemon: server socket setup failed, retry 1: spamd: could not create IO::Socket::INET6 socket on [::1]:783: Cannot assign requested address
server socket setup failed, retry 2: spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
server socket setup failed, retry 3: spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
server socket setup failed, retry 4: spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
server socket setup failed, retry 5: spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
server socket setup failed, retry 6: spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
server socket setup failed, retry 7: spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
server socket setup failed, retry 8: spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
server socket setup failed, retry 9: spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use
spamd: could not create IO::Socket::INET6 socket on [127.0.0.1]:783: Address already in use

I have tried,

netstat -lptn

it's showing,

there is process running with 127.0.1.1:783

also tried,

sudo netstat -lepnt

am getting,

here too not showing any process run with 127.0.1.1:783

Please tell me where the problem cause ?

I added group using the command in terminal as,

$ sudo addgroup XXX

And I add user under that group,

$ sudo adduser --ingroup XXX YYY

Now, I need to remove the same group as well as user(s), how to do?

I have downloaded 'jdk-7u55-linux-x64.tar.gz'

When I execute following command to extract,

 sudo tar xvzf jdk-7u55-linux-x64.tar.gz

also tried,

sudo tar xvf jdk-7u55-linux-x64.tar.gz
sudo tar xf jdk-7u55-linux-x64.tar.gz
sudo tar -xvf jdk-7u55-linux-x64.tar.gz

But am getting error at last as,

gzip: stdin: unexpected end of file
tar: Unexpected EOF in archive
tar: Unexpected EOF in archive
tar: Error is not recoverable: exiting now

How to resolve this ?

I have installed hadoop-2.4.0 in my 14.04 LTS,

I have followed this link, I have done upto start and stop services successfully,

but when I tried to execute example,

$ /bin/hadoop jar hadoop*examples*.jar wordcount /user/hduser/gutenberg /user/hduser/gutenberg-output

and I am getting response as,

Not a valid JAR: /hadoop*examples*.jar

EDIT 1

I have installed JAVA 7(i.e JDK 1.7) and when I used Hadoop-1.0.3 it works fine.

Problem cause when I try to execute with Hadoop-2.4.0.

NOTE

From this tutorial my system differ the following,

1. I am using JAVA 7 instead of JAVA 6.
2. I am using Hadoop 2.4.0 instead of Hadoop-1.0.3
3. I am usinh Ubuntu 14.04 instead of Ubuntu 10.04.

And I can successfully execute HAdoop-1.0.3 with JAVA 7 on 14.04.

My question why can't I run the same for Hadoop-2.4.0.

I tried to check configured ports from hadoop user as, sudo netstat -p1ten | grep java

But, I am getting result as,

[sudo] password for hadoopz: hadoopz is not in the sudoers file. This incident will be reported.

How to get sudo permission for hadoop user ??

hadoopz@ubuntu:/usr/local/hadoop$ jps

The program 'jps' can be found in the following packages:

• openjdk-7-jdk
• openjdk-6-jdk

Ask your administrator to install one of them

When I check jps for Hadoop, I am getting the above result....

I am using Ubuntu 14.04. And I have done the following to disable ipv6.

I have open /etc/sysctl.conf using gedit and paste the following lines at the end of sysctl.conf.

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1 

But when I check it using following command,

$ cat /proc/sys/net/ipv6/conf/all/disable_ipv6

I am getting result as '0'( i.e still Enabled). Please help me to disable ipv6, so that I can use hadoop.

I followed instructions from this link.