I was using ubuntu 12.04 ,on which I run ulimit -n ,it is showing 1024,
I want to increase my open file limit from 1024 to 65535,so I tried the following command:
    
    sudo ulimit -n 65535

but i get the following error:

    sudo: ulimit: command not found


How to increase the file limit from 1024 to 65535? Any help will be appreciated.

 

command not found when using sudo ulimit

I am trying to install pymssql on ubuntu 12.04 using pip. This is the error I am getting. Any help would be greatly appreciated as I am completely lost!

Tried googling this but unfortunately to no avail...

      Downloading pymssql-2.0.0b1-dev-20130403.tar.gz (2.8Mb): 2.8Mb downloaded
      Running setup.py egg_info for package pymssql
        warning: no files found matching &#39;*.pyx&#39; under directory &#39;Cython/Debugger/Tests&#39;
        warning: no files found matching &#39;*.pxd&#39; under directory &#39;Cython/Debugger/Tests&#39;
        warning: no files found matching &#39;*.h&#39; under directory &#39;Cython/Debugger/Tests&#39;
        warning: no files found matching &#39;*.pxd&#39; under directory &#39;Cython/Utility&#39;
        Compiling module Cython.Plex.Scanners ...
        Compiling module Cython.Plex.Actions ...
        Compiling module Cython.Compiler.Lexicon ...
        Compiling module Cython.Compiler.Scanning ...
        Compiling module Cython.Compiler.Parsing ...
        Compiling module Cython.Compiler.Visitor ...
        Compiling module Cython.Compiler.FlowControl ...
        Compiling module Cython.Compiler.Code ...
        Compiling module Cython.Runtime.refnanny ...
        
        Installed /home/radek/build/pymssql/Cython-0.19.1-py2.7-linux-x86_64.egg
        cc -c /tmp/clock_gettimeh7sDgX.c -o tmp/clock_gettimeh7sDgX.o
        cc tmp/clock_gettimeh7sDgX.o -lrt -o a.out
        
        warning: no files found matching &#39;win32/freetds.zip&#39;
    Installing collected packages: pymssql
      Running setup.py install for pymssql
        skipping &#39;_mssql.c&#39; Cython extension (up-to-date)
        building &#39;_mssql&#39; extension
        gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I/home/radek/build/pymssql/freetds/nix_64/include -I/usr/include/python2.7 -c _mssql.c -o build/temp.linux-x86_64-2.7/_mssql.o -Wno-parentheses-equality -DMSDBLIB
        gcc -pthread -shared -Wl,-O1 -Wl,-Bsymbolic-functions -Wl,-Bsymbolic-functions -Wl,-z,relro build/temp.linux-x86_64-2.7/_mssql.o -L/home/radek/build/pymssql/freetds/nix_64/lib -lsybdb -lct -lrt -o build/lib.linux-x86_64-2.7/_mssql.so
        /usr/bin/ld: cannot find -lct
        collect2: ld returned 1 exit status
        error: command &#39;gcc&#39; failed with exit status 1
        Complete output from command /usr/bin/python -c &quot;import setuptools;__file__=&#39;/home/radek/build/pymssql/setup.py&#39;;exec(compile(open(__file__).read().replace(&#39;\r\n&#39;, &#39;\n&#39;), __file__, &#39;exec&#39;))&quot; install --single-version-externally-managed --record /tmp/pip-Et_P1_-record/install-record.txt:
        running install
    
    running build
    
    running build_ext
    
    skipping &#39;_mssql.c&#39; Cython extension (up-to-date)
    
    building &#39;_mssql&#39; extension
    
    creating build
    
    creating build/temp.linux-x86_64-2.7
    
    gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I/home/radek/build/pymssql/freetds/nix_64/include -I/usr/include/python2.7 -c _mssql.c -o build/temp.linux-x86_64-2.7/_mssql.o -Wno-parentheses-equality -DMSDBLIB
    
    creating build/lib.linux-x86_64-2.7
    
    gcc -pthread -shared -Wl,-O1 -Wl,-Bsymbolic-functions -Wl,-Bsymbolic-functions -Wl,-z,relro build/temp.linux-x86_64-2.7/_mssql.o -L/home/radek/build/pymssql/freetds/nix_64/lib -lsybdb -lct -lrt -o build/lib.linux-x86_64-2.7/_mssql.so
    
    /usr/bin/ld: cannot find -lct
    
    collect2: ld returned 1 exit status
    
    error: command &#39;gcc&#39; failed with exit status 1
    
    ----------------------------------------
    Command /usr/bin/python -c &quot;import setuptools;__file__=&#39;/home/radek/build/pymssql/setup.py&#39;;exec(compile(open(__file__).read().replace(&#39;\r\n&#39;, &#39;\n&#39;), __file__, &#39;exec&#39;))&quot; install --single-version-externally-managed --record /tmp/pip-Et_P1_-record/install-record.txt failed with error code 1

trying to install pymssql on ubuntu 12.04 using pip

I have installed:

 - eclipse juno
 - java-6-openjdk-i386 (selected as default JRE in Eclipse)
 - java-7-openjdk-i386

When I try to add a new server Tomcat7, in Eclipse, I get this message 

**&#39;Cannot create a server using the selected type&#39;**

and I can not continue. No problem adding Tomcat6 server.

I read this [question][1] but it didn&#39;t solve it for me 


  [1]: https://stackoverflow.com/questions/8025841/eclipse-3-7-indigo-tomcat7-cannot-create-a-server-using-the-selected-typ

Eclipse 4.2 (Juno) &#39;Cannot create a server using the selected type&#39; in Tomcat 7

I&#39;m unable to ssh to my EC2 server and am getting the error:

    ssh -i /Users/Skeniver/Keepass/skeniver.pem ubuntu@xx.xxx.xx.xxx

    Identity file /Users/Skeniver/Keepass/skeniver.pem not accessible: No such file or directory

The file is definitely in the directory and I&#39;ve chmod&#39;d the directory to 755 and the file to 600:

    drwxr-xr-x  14 Skeniver  staff    476 28 Nov  2012 Keepass
    -rw-------  1 Skeniver  staff    1696  5 Oct  2012 skeniverkey.pem

I&#39;m pretty sure it&#39;s a permissions problem, but can&#39;t figure out why...

Here is the output of the ssh command using -v, in case it&#39;s of any use:

    Warning: Identity file /Users/Skeniver/Keepass/skeniver.pem not accessible: No such file or directory.
    OpenSSH_5.2p1, OpenSSL 0.9.8r 8 Feb 2011
    debug1: Reading configuration data /etc/ssh_config
    debug1: Connecting to xx.xxx.xx.xxx [xx.xxx.xx.xxx] port 22.
    debug1: Connection established.
    debug1: identity file /Users/Skeniver/.ssh/identity type -1
    debug1: identity file /Users/Skeniver/.ssh/id_rsa type 1
    debug1: identity file /Users/Skeniver/.ssh/id_dsa type -1
    debug1: Remote protocol version 2.0, remote software version OpenSSH_5.9p1 Debian-5ubuntu1.1
    debug1: match: OpenSSH_5.9p1 Debian-5ubuntu1.1 pat OpenSSH*
    debug1: Enabling compatibility mode for protocol 2.0
    debug1: Local version string SSH-2.0-OpenSSH_5.2
    debug1: SSH2_MSG_KEXINIT sent
    debug1: SSH2_MSG_KEXINIT received
    debug1: kex: server-&gt;client aes128-ctr hmac-md5 none
    debug1: kex: client-&gt;server aes128-ctr hmac-md5 none
    debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024&lt;1024&lt;8192) sent
    debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
    debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
    debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
    debug1: Host &#39;xx.xxx.xx.xxx&#39; is known and matches the RSA host key.
    debug1: Found key in /Users/Skeniver/.ssh/known_hosts:8
    debug1: ssh_rsa_verify: signature correct
    debug1: SSH2_MSG_NEWKEYS sent
    debug1: expecting SSH2_MSG_NEWKEYS
    debug1: SSH2_MSG_NEWKEYS received
    debug1: SSH2_MSG_SERVICE_REQUEST sent
    debug1: SSH2_MSG_SERVICE_ACCEPT received
    debug1: Authentications that can continue: publickey
    debug1: Next authentication method: publickey
    debug1: Offering public key: /Users/Skeniver/.ssh/id_rsa
    debug1: Authentications that can continue: publickey
    debug1: Trying private key: /Users/Skeniver/.ssh/identity
    debug1: Trying private key: /Users/Skeniver/.ssh/id_dsa
    debug1: No more authentication methods to try.
    Permission denied (publickey).

Can&#39;t ssh to AWS EC2: Identity file not accessible

I have a VirtualBox machine running Ubuntu 12.04 in a Mac OS X host machine. In my host machine (Mac OS X), I have PostgreSQL installed. I would like to connect to this PostgreSQL server **from** my Ubuntu virtual machine (I know normally it&#39;s the opposite way).

I guess I should configure some networking parameters in VirtualBox itself. All I get from [Vagrant docs][1] is I need to assign my vm a static IP to use a private network. But once created, how do I reach my host from my guest? 

I didn&#39;t find anything like that in vagrant docs. So, there&#39;s probably a good reason for that. Does it make sense? I don&#39;t want to duplicate PostgreSQL installation. Just use my current existent one.

  [1]: http://docs.vagrantup.com/v2/networking/private_network.html

How to connect with host PostgreSQL from vagrant virtualbox machine

I have a dual monitor setup, and I am using Ubuntu 12.04 LTS
I have changed the positioning of the monitors several times, and now for some reason some of the windows open up off-screen (outside of both screens), Update Manager, for instance.
How can I position the windows on one of my screens?

Window appears off screen on ubuntu

I do not know the service&#39;s name, but would like to stop the service by checking its status. 

For example, if I want to check if the [PostgreSQL][1] service is running or not, but I don&#39;t know the service&#39;s name, then how could I check its status?

I know the command to check the status if the service name is known.

  [1]: http://en.wikipedia.org/wiki/PostgreSQL


How to check if a service that I don&#39;t know the name of is running on Ubuntu

I am trying to compile ARM code on [Ubuntu 12.04][1] (Precise Pangolin).

Everything is working fine when I put the code in the local directory.

But when I put the code in the cited mount directory, an error shows up:

    making testXmlFiles
    sh: 0: getcwd() failed: No such file or directory
    ARM Compiling xxxxx.c
    sh: 0: getcwd() failed: No such file or directory

Here is my setting in [fstab][2]:

    //10.0.0.1/data /mnt/data   cifs    auto,noserverino,credentials=/root/.smbcredentials,file_mode=0777,dir_mode=0777,uid=user,gid=users,noperm 0 0

What is going on here? What could cause this error?

  [1]: https://en.wikipedia.org/wiki/Ubuntu_version_history#Ubuntu_12.04_LTS_.28Precise_Pangolin.29
  [2]: https://en.wikipedia.org/wiki/Fstab






sh: 0: getcwd() failed: No such file or directory on cited drive

I&#39;m trying to use the barbecue barcode printing library. I have successfully added the library to IntelliJ through project structure add library.  Then I imported the packages and wrote the methods, which gave me no error.  The packages were available in the class.

But when I compile it gives me the error:

    error: package net.sourceforge.barbecue does not exist

How can this be?

I&#39;m coding in ubuntu, is there any other place to which I have to add the library?


Why does IntelliJ give me &quot;Package doesn&#39;t exist&quot; error?

What is use of these two directories in Apache&amp;nbsp;2 and how can we do it?


What is the difference between the &#39;sites-enabled&#39; and &#39;sites-available&#39; directory?

I know this sounds stupid, but when I use

    SELECT CONVERT_TZ(&#39;2004-01-01 12:00:00&#39;,&#39;UTC&#39;,&#39;Asia/Jakarta&#39;) AS time

it outputs NULL. I&#39;m using MySQL Workbench in Ubuntu 12.04 64 bit, and it works in my other laptop/os (also using MySQL Workbench).


convert_tz returns null

I am trying to run the JUnit on my Linux command prompt `/opt/junit/` contains the necessary JARS(hamcrest-core-1.3.jar and junit.jar) and class files and I am using the following command to run the JUnit: 

    java -cp hamcrest-core-1.3.jar:junit.jar:. org.junit.runner.JUnitCore  TestRunner

TestJunit class:

    import org.junit.Test;
    import static org.junit.Assert.assertEquals;
    public class TestJunit {
       @Test
       public void testAdd() {
          String str= &quot;Junit is working fine&quot;;
          assertEquals(&quot;Junit is working fine&quot;,str);
       }
    }

TestRunner:

    import org.junit.runner.JUnitCore;
    import org.junit.runner.Result;
    import org.junit.runner.notification.Failure;
    
    public class TestRunner {
       public static void main(String[] args) {
          Result result = JUnitCore.runClasses(TestJunit.class);
          for (Failure failure : result.getFailures()) {
             System.out.println(&quot;fail ho gaya&quot;+failure.toString());
          }
          System.out.println(&quot;passed:&quot;+result.wasSuccessful());
       }
    }  

I am getting the following exception on running this

    JUnit version 4.11
    .E
    Time: 0.003
    There was 1 failure:
    1) initializationError(TestRunner)
    java.lang.Exception: No runnable methods
    	at org.junit.runners.BlockJUnit4ClassRunner.validateInstanceMethods(BlockJUnit4ClassRunner.java:169)
    	at org.junit.runners.BlockJUnit4ClassRunner.collectInitializationErrors(BlockJUnit4ClassRunner.java:104)
    	at org.junit.runners.ParentRunner.validate(ParentRunner.java:355)
    	at org.junit.runners.ParentRunner.&lt;init&gt;(ParentRunner.java:76)
    	at org.junit.runners.BlockJUnit4ClassRunner.&lt;init&gt;(BlockJUnit4ClassRunner.java:57)
    	at org.junit.internal.builders.JUnit4Builder.runnerForClass(JUnit4Builder.java:10)
    	at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
    	at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:26)
    	at org.junit.runner.Computer.getRunner(Computer.java:40)
    	at org.junit.runner.Computer$1.runnerForClass(Computer.java:31)
    	at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
    	at org.junit.runners.model.RunnerBuilder.runners(RunnerBuilder.java:101)
    	at org.junit.runners.model.RunnerBuilder.runners(RunnerBuilder.java:87)
    	at org.junit.runners.Suite.&lt;init&gt;(Suite.java:80)
    	at org.junit.runner.Computer.getSuite(Computer.java:28)
    	at org.junit.runner.Request.classes(Request.java:75)
    	at org.junit.runner.JUnitCore.run(JUnitCore.java:117)
    	at org.junit.runner.JUnitCore.runMain(JUnitCore.java:96)
    	at org.junit.runner.JUnitCore.runMainAndExit(JUnitCore.java:47)
    	at org.junit.runner.JUnitCore.main(JUnitCore.java:40)
    
    FAILURES!!!
    Tests run: 1,  Failures: 1



java.lang.Exception: No runnable methods exception in running JUnits

I created a dump with mongodump on computer A (ubuntu 12.04 server). I moved it to computer B (ubuntu 12.04 server) and typed:

&gt; mongorestore -db db_name --drop db_dump_path

It failed and it reported:

&gt; connected to: 127.0.0.1&lt;br&gt;
&gt; terminate called after throwing an instance of &#39;std::runtime_error&#39;&lt;br&gt;
&gt; what():  locale::facet::_S_create_c_locale name not valid&lt;br&gt;
&gt; Aborted

I&#39;ve successfully accomplished this operation before and this strange behavior has never occurred. What do I need to do to fix this?

MongoDB mongorestore failure: locale::facet::_S_create_c_locale name not valid

We are looking to upgrade the OS on our servers from Ubuntu 10.04 LTS to Ubuntu 12.04 LTS. Unfortunately, it seems that the latency to run a thread that has become runnable has significantly increased from the 2.6 kernel to the 3.2 kernel. In fact the latency numbers we are getting are hard to believe.

Let me be more specific about the test. We have a program that runs two threads. The first thread gets the current time (in ticks using RDTSC) and then signals a condition variable once a second. The second thread waits on the condition variable and wakes up when it is signaled. It then gets the current time (in ticks using RDTSC). The difference between the time in the second thread and the time in the first thread is computed and displayed on the console. After this the second thread waits on the condition variable once more. It will be signaled again by the first thread after about a second passes. 

So, in a nutshell we get a *thread to thread communication via condition variable* latency measurement once a second as a result.

In kernel 2.6.32, this latency is somewhere on the order of 2.8-3.5 us, which is reasonable. In kernel 3.2.0, this latency has increased to somewhere on the order of 40-100 us. I have excluded any differences in hardware between the two hosts. They run on identical hardware (dual socket X5687 {Westmere-EP} processors running at 3.6 GHz with hyperthreading, speedstep and all C states turned off). The test app changes the affinity of the threads to run them on independent physical cores of the same socket (i.e., the first thread is run on Core 0 and the second thread is run on Core 1), so there is no bouncing of threads on cores or bouncing/communication between sockets.

The only difference between the two hosts is that one is running Ubuntu 10.04 LTS with kernel 2.6.32-28 (the fast context switch box) and the other is running the latest Ubuntu 12.04 LTS with kernel 3.2.0-23 (the slow context switch box). All BIOS settings and hardware are identical.

Have there been any changes in the kernel that could account for this ridiculous slow down in how long it takes for a thread to be scheduled to run?

**Update:**
If you would like to run the test on your host and linux build, I have [posted the code to pastebin] for your perusal. Compile with:

    g++ -O3 -o test_latency test_latency.cpp -lpthread

Run with (assuming you have at least a dual-core box):

    ./test_latency 0 1 # Thread 1 on Core 0 and Thread 2 on Core 1

[posted the code to pastebin]: http://pastebin.com/3sx8Vhf1

**Update 2**:
After much searching through kernel parameters, posts on kernel changes and personal research, I have figured out what the problem is and have posted the solution as an answer to this question.


Context switches much slower in new linux kernels

We need to transfer `15TB` of data from one server to another as fast as we can. We&#39;re currently using `rsync` but we&#39;re only getting speeds of around `150Mb/s`, when our network is capable of `900+Mb/s` (tested with `iperf`). I&#39;ve done tests of the disks, network, etc and figured it&#39;s just that rsync is only transferring one file at a time which is causing the slowdown.

I found a script to run a different rsync for each folder in a directory tree (allowing you to limit to x number), but I can&#39;t get it working, it still just runs one rsync at a time.

I found the `script` [here][1] (copied below).

Our directory tree is like this:

    /main
       - /files
          - /1
             - 343
                - 123.wav
                - 76.wav
             - 772
                - 122.wav
             - 55
                - 555.wav
                - 324.wav
                - 1209.wav
             - 43
                - 999.wav
                - 111.wav
                - 222.wav
          - /2
             - 346
                - 9993.wav
             - 4242
                - 827.wav
          - /3
             - 2545
                - 76.wav
                - 199.wav
                - 183.wav
             - 23
                - 33.wav
                - 876.wav
             - 4256
                - 998.wav
                - 1665.wav
                - 332.wav
                - 112.wav
                - 5584.wav

So what I&#39;d like to happen is to create an rsync for each of the directories in /main/files, up to a maximum of, say, 5 at a time. So in this case, 3 rsyncs would run, for `/main/files/1`, `/main/files/2` and `/main/files/3`.

I tried with it like this, but it just runs 1 rsync at a time for the `/main/files/2` folder:

    #!/bin/bash
    
    # Define source, target, maxdepth and cd to source
    source=&quot;/main/files&quot;
    target=&quot;/main/filesTest&quot;
    depth=1
    cd &quot;${source}&quot;
    
    # Set the maximum number of concurrent rsync threads
    maxthreads=5
    # How long to wait before checking the number of rsync threads again
    sleeptime=5
    
    # Find all folders in the source directory within the maxdepth level
    find . -maxdepth ${depth} -type d | while read dir
    do
    	# Make sure to ignore the parent folder
    	if [ `echo &quot;${dir}&quot; | awk -F&#39;/&#39; &#39;{print NF}&#39;` -gt ${depth} ]
    	then
    		# Strip leading dot slash
    		subfolder=$(echo &quot;${dir}&quot; | sed &#39;s@^\./@@g&#39;)
    		if [ ! -d &quot;${target}/${subfolder}&quot; ]
    		then
    			# Create destination folder and set ownership and permissions to match source
    			mkdir -p &quot;${target}/${subfolder}&quot;
    			chown --reference=&quot;${source}/${subfolder}&quot; &quot;${target}/${subfolder}&quot;
    			chmod --reference=&quot;${source}/${subfolder}&quot; &quot;${target}/${subfolder}&quot;
    		fi
    		# Make sure the number of rsync threads running is below the threshold
    		while [ `ps -ef | grep -c [r]sync` -gt ${maxthreads} ]
    		do
    			echo &quot;Sleeping ${sleeptime} seconds&quot;
    			sleep ${sleeptime}
    		done
    		# Run rsync in background for the current subfolder and move one to the next one
    		nohup rsync -a &quot;${source}/${subfolder}/&quot; &quot;${target}/${subfolder}/&quot; &lt;/dev/null &gt;/dev/null 2&gt;&amp;1 &amp;
    	fi
    done
    
    # Find all files above the maxdepth level and rsync them as well
    find . -maxdepth ${depth} -type f -print0 | rsync -a --files-from=- --from0 ./ &quot;${target}/&quot;


  [1]: http://www.krazyworks.com/making-rsync-faster/

Speed up rsync with Simultaneous/Concurrent File Transfers?

I am new to Python and want to use its `plot` functionality to create graphs. I am using ubuntu 12.04. I followed the Python installation steps from http://eli.thegreenplace.net/2011/10/10/installing-python-2-7-on-ubuntu/ but when I do 

    from pylab import *

I am getting this error

    &gt;&gt;&gt; from pylab import *
    Traceback (most recent call last):
      File &quot;&lt;stdin&gt;&quot;, line 1, in &lt;module&gt;
    ImportError: No module named pylab

My Python version is `python 2.7`. Can anybody tell me what I am missing here?


python error: no module named pylab

Ubuntu 12.04, nginx 1.2.0, uwsgi 1.0.3.

I start uwsgi with the following command:

    uwsgi -s 127.0.0.1:9010 -M -t 30 -A 4 -p 4 -d /var/log/uwsgi.log

On each request nginx replies with 502 and uwsgi writes to log the following line:

    -- unavailable modifier requested: 0 --

nginx + uwsgi: -- unavailable modifier requested: 0 --

I have both `python2.7` and `python3.2` installed in `Ubuntu 12.04`.  
The symbolic link `python` links to `python2.7`.

When I type:

    sudo pip install package-name

It will default install `python2` version of `package-name`.

Some package supports both `python2` and `python3`.  
How to install `python3` version of `package-name` via `pip`?


How to install python3 version of package via pip on Ubuntu?

I have set up a cronjob for root user in ubuntu environment as follows by typing `crontab -e`

      34 11 * * * sh /srv/www/live/CronJobs/daily.sh
      0 08 * * 2 sh /srv/www/live/CronJobs/weekly.sh
      0 08 1 * * sh /srv/www/live/CronJobs/monthly.sh

But the cronjob does not run. I have tried checking if the cronjob is running using `pgrep cron` and that gives process id 3033. The shell script calls a python file and is used to send an email. Running the python file is ok. There&#39;s no error in it but the cron doesn&#39;t run. The daily.sh file has the following code in it.

    python /srv/www/live/CronJobs/daily.py
    python /srv/www/live/CronJobs/notification_email.py
    python /srv/www/live/CronJobs/log_kpi.py





CronJob not running

I have a `Postgres db 9.1` running on `AWS EC2`, with `ubuntu 12.04`.

I messed a lot with the instance (i.e installed all kinds of postgres X.X before i settled on 9.1).

Now after a month working on that db, I discovered that if I restart my instance `postgres` doesn&#39;t load correctly, its status says &quot;Running clusters&quot;. this will last forever until I


    sudo service postgresql restart

from terminal, and then it works again.

How do I add this line, to ubuntu startup so that each time it loads, it will restart this service, and hopefully solve my problem?

Also any other solution which might solve this.

postgres, ubuntu how to restart service on startup? get stuck on clustering after instance reboot

I&#39;m using Ubuntu Linux 12.04 LTS on my local machine. I&#39;ve installed LAMP long ago on my machine. Now I want to enable following PHP extensions:

 1. php_zip
 2. php_xml
 3. php_gd2

For it first I want to check whether these PHP extensions are enabled or not. I searched a lot about how to check the installed/enabled PHP extensions but every time I found how to install these extensions on Ubuntu Linux. So can someone please let me know how should I check the enabled/disabled PHP extensions in Ubuntu Linux 12.04 LTS? Thanks in advance.

How to check which PHP extensions have been enabled/disabled in Ubuntu Linux 12.04 LTS?

Recently I set up a new EC2 instance. The next day I was not able to connect to my instance via ssh. I could connect and disconnect the day before, I am sure I did nothing. Here is ssh debug info:


    ssh -i webserver.pem -v ubuntu@my.elastic.ip
    OpenSSH_5.9p1, OpenSSL 0.9.8r 8 Feb 2011
    debug1: Reading configuration data /etc/ssh_config
    debug1: /etc/ssh_config line 20: Applying options for *
    debug1: Connecting to my.elastic.ip [my.elastic.ip] port 22.
    debug1: Connection established.
    debug1: identity file webserver.pem type -1
    debug1: identity file webserver.pem-cert type -1
    debug1: Remote protocol version 2.0, remote software version OpenSSH_5.9p1 Debian-5ubuntu1.1
    debug1: match: OpenSSH_5.9p1 Debian-5ubuntu1.1 pat OpenSSH*
    debug1: Enabling compatibility mode for protocol 2.0
    debug1: Local version string SSH-2.0-OpenSSH_5.9
    debug1: SSH2_MSG_KEXINIT sent
    Connection closed by my.elastic.ip

Is there a way to resolve this issue? Or shall I reinstall my instance again?

PS rights to my .pem are set to 600.

AWS EC2 Connection closed by when trying ssh into instance

I&#39;ve just installed a Ubuntu 12.04 server and nginx 1.2.7, removed `default` from sites-enabled and added my own file into `sites-available` and symlink at `sites-enabled`. Then restarted nginx.

**Problem:** However going to the URL does not load the site. `netstat -nlp | grep nginx` and `netstat -nlp | grep 80` both returns no results! `lsof -i :80` also returns nothing. A `dig` from another server returns the correct ip address so it shouldn&#39;t be a DNS problem. I was able to connect to apache which I have now stopped its service. nginx logs also show nothing.

How should I troubleshoot this problem?

**/etc/nginx/site-available/mysite.com**

    server {
        listen   80;
        server_name www.mysite.com mysite.com *.mysite.com;
        access_log /var/log/nginx/access.log;
        error_log /var/log/nginx/error.log;
        root /var/www/mysite/public;

        index index.php index.html;
        
        location / {
            try_files $uri $uri/ /index.php?$args ;
        }
        location ~ \.php$ {
            fastcgi_pass unix:/var/run/php5-fpm.sock;
            fastcgi_index index.php;
            include fastcgi_params;
            fastcgi_read_timeout 300;
        }

    }

nginx not listening to port 80

I am facing an issue on ubuntu 12.04 as :

&gt; /usr/lib/ndk/android-ndk-r8c/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/as:
&gt; error while loading shared libraries: libz.so.1: cannot open shared
&gt; object file: No such file or directory

I tried 

    sudo apt-get install lib32z1

But it says 

&gt; Reading package lists... Done Building dependency tree        Reading
&gt; state information... Done lib32z1 is already the newest version. 0
&gt; upgraded, 0 newly installed, 0 to remove and 610 not upgraded.

Please suggest a solution.

libz.so.1: cannot open shared object file

Okay, so, I switched from ubuntu 12.04 64-bit to 32-bit and installed `build-essential.`

I then compiled and installed GMP-5.0.5, MPFR-3.1.1, MPC-1.0, ISL-0.10 and CLOOG-0.17.0. I checked out a copy of the main gcc trunk and attempted to build it with the following configure line (from a separate directory):

    ../svnsrc/configure --prefix=/usr/GCC/svn --enable-__cxa_atexit --with-plugin-ld=/usr/bin/ld.gold --enable-threads=posix --enable-werror --enable-build-with-cxx --with-gmp=/usr/GCC/prereq/svn --with-mpfr=/usr/GCC/prereq/svn --with-mpc=/usr/GCC/prereq/svn --with-isl=/usr/GCC/prereq/svn --with-cloog=/usr/GCC/prereq/svn --enable-languages=c,c++

Configure ran fine and so I ran `make &amp;&amp; make check`. This ran fine for a while, but then it failed with the following error:

    /home/matt/GCC/svnbuild/./gcc/xgcc -B/home/matt/GCC/svnbuild/./gcc/ -B/usr/GCC/svn/i686-pc-linux-gnu/bin/ -B/usr/GCC/svn/i686-pc-linux-gnu/lib/ -isystem /usr/GCC/svn/i686-pc-linux-gnu/include -isystem /usr/GCC/svn/i686-pc-linux-gnu/sys-include    -g -O2 -O2  -g -O2 -DIN_GCC   -W -Wall -Wwrite-strings -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition  -isystem ./include   -fpic -mlong-double-80 -g -DIN_LIBGCC2 -fbuilding-libgcc -fno-stack-protector   -fpic -mlong-double-80 -I. -I. -I../.././gcc -I../../../svnsrc/libgcc -I../../../svnsrc/libgcc/. -I../../../svnsrc/libgcc/../gcc -I../../../svnsrc/libgcc/../include -I../../../svnsrc/libgcc/config/libbid -DENABLE_DECIMAL_BID_FORMAT -DHAVE_CC_TLS  -DUSE_TLS -o _muldi3.o -MT _muldi3.o -MD -MP -MF _muldi3.dep -DL_muldi3 -c ../../../svnsrc/libgcc/libgcc2.c -fvisibility=hidden -DHIDE_EXPORTS
    In file included from /usr/include/stdio.h:28:0,
                     from ../../../svnsrc/libgcc/../gcc/tsystem.h:88,
                     from ../../../svnsrc/libgcc/libgcc2.c:29:
    /usr/include/features.h:324:26: fatal error: bits/predefs.h: No such file or directory
     #include &lt;bits/predefs.h&gt;
                              ^
    compilation terminated.
    make[3]: *** [_muldi3.o] Error 1
    make[3]: Leaving directory `/home/matt/GCC/svnbuild/i686-pc-linux-gnu/libgcc
I looked around, but everything I seemed to find was that this error was caused on x86_64, by not installing `gcc-multilib`, because Ubuntu and Debian use the mutiarch system, separating the libraries. Okay, fine...but I&#39;m using i686, so why would I need the 64-bit libraries? Any help would be appreciated. Thanks.

gcc cannot find bits/predefs.h on i686

I installed an openflow controller on my Ubuntu 12.04 called RYU using: 

     sudo  pip install ryu

I was trying to run a python file using ryu-manager as shown below.

    sudo ryu-manager simple_switch.py 
    Traceback (most recent call last):
      File &quot;/usr/local/bin/ryu-manager&quot;, line 19, in &lt;module&gt;
        import gevent
    ImportError: No module named gevent

Then I tried to install gevent using:

    sudo pip install gevent
    gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fPIC -I/usr/include/python2.7 -c gevent/core.c -o build/temp.linux-x86_64-2.7/gevent/core.o
    gevent/core.c:4:20: fatal error: Python.h: No such file or directory

    compilation terminated.
    
    error: command &#39;gcc&#39; failed with exit status 1

What is the cause of this error? I tried to locate `Python.h` using `sudo locate Python.h`, but without success. The output of `python -V` however is

    Python 2.7.3

Should `Python.h` be there on the system? If so, what should I install to get it?

Python.h missing from Ubuntu 12.04

How do I go about sharing a folder between the host (Mac) and the guest OS (Ubuntu) in Virtual Box?

Share folders from the host Mac OS to a guest Linux system in VirtualBox

I want to install ruby **2.0** using

    sudo apt-get install ruby2.0

But there isn&#39;t available package for ruby2.0

I want to install it using **apt-get install** the same like ruby 1.9.1

Any suggestions?

How to install Ruby 2 on Ubuntu without RVM

I have a problem with phpmyadmin on ubuntu 12.04.
I have already installed apache2, php5, mysql and phpmyadmin.

The `phpinfo();` script, don&#39;t show nothing about mysqli or mysql extension.

When I try start phpmyadmin this error appear:

&lt;pre&gt;
----
**phpMyAdmin - Error**
-------
**The mysqli extension is missing. Please check your PHP configuration.**
----
&lt;/pre&gt;

In the php.ini file, I uncommented `extension=mysql.so` line, but doesn&#39;t work...

Anyone have another posible solution?


Extension mysqli is missing, phpmyadmin doesn&#39;t work

I have downloaded latest SmartGit installation and each time I want to use it I need to run script smartgit.sh from SmartGit bin directory, this process requires the same repository setup every time.

What it correct way of installing SmartGit on Ubuntu? Thus I can have normal icon and run the program from state of previous usage, without configuring repositories every time.

Thanks.

SmartGit Installation and Usage on Ubuntu

I have installed sbt on Ubuntu.

    :~/bin/sbt/bin$ ls
    classes    sbt      sbt-launch.jar       target
    jansi.jar  sbt.bat  sbt-launch-lib.bash  win-sbt

However, whenever I try to launch sbt (from the same directory where sbt is located) it does not work:

    No command &#39;sbt&#39; found, did you mean:
     Command &#39;skt&#39; from package &#39;latex-sanskrit&#39; (universe)
     Command &#39;sb2&#39; from package &#39;scratchbox2&#39; (universe)
     Command &#39;sbd&#39; from package &#39;cluster-glue&#39; (main)
     Command &#39;mbt&#39; from package &#39;mbt&#39; (universe)
     Command &#39;sbmt&#39; from package &#39;atfs&#39; (universe)
     Command &#39;lbt&#39; from package &#39;lbt&#39; (universe)
     Command &#39;st&#39; from package &#39;suckless-tools&#39; (universe)
     Command &#39;sb&#39; from package &#39;lrzsz&#39; (universe)

I am new to linux and I have no idea how to tackle this issue.


Install sbt on ubuntu

I am using ubuntu 12.04 and I am trying to pip install virtualenv but suddenly I got this error.

    samuel@sampc:~$ pip install virtualenv
    Downloading/unpacking virtualenv
      Running setup.py egg_info for package virtualenv
        
        warning: no previously-included files matching &#39;*&#39; found under directory &#39;docs/_templates&#39;
        warning: no previously-included files matching &#39;*&#39; found under directory &#39;docs/_build&#39;
    Installing collected packages: virtualenv
      Running setup.py install for virtualenv
        error: could not create &#39;/usr/local/lib/python2.7/dist-packages/virtualenv_support&#39;: Permission denied
        Complete output from command /usr/bin/python -c &quot;import setuptools;__file__=&#39;/home/samuel/build/virtualenv/setup.py&#39;;exec(compile(open(__file__).read().replace(&#39;\r\n&#39;, &#39;\n&#39;), __file__, &#39;exec&#39;))&quot; install --single-version-externally-managed --record /tmp/pip-Z2v_fR-record/install-record.txt:
        running install
    
    running build
    
    running build_py
    
    running install_lib
    
    creating /usr/local/lib/python2.7/dist-packages/virtualenv_support
    
    error: could not create &#39;/usr/local/lib/python2.7/dist-packages/virtualenv_support&#39;: Permission denied
    
    ----------------------------------------
    Command /usr/bin/python -c &quot;import setuptools;__file__=&#39;/home/samuel/build/virtualenv/setup.py&#39;;exec(compile(open(__file__).read().replace(&#39;\r\n&#39;, &#39;\n&#39;), __file__, &#39;exec&#39;))&quot; install --single-version-externally-managed --record /tmp/pip-Z2v_fR-record/install-record.txt failed with error code 1
    Storing complete log in /home/samuel/.pip/pip.log


Does anyone have an idea about my case?


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