Posts Tagged ‘distributions’

Install postgresql on Debian Squeeze / How to install PostGreSQL on Obsolete Debian installation

Friday, June 10th, 2016


If you're in position like me to be running an old version of Debian (Squeeze) and you need to install PostgreSQL you will notice that the Debian 6.0 standard repositories are no longer active and apt-get update && apt-get upgrade are returning errors, thus because this Debian release is already too old and even the LTS repositories are inactive it is impossible to install postgresql with the usual.

To get around the situation first thing I did was to try to add followin Debian  repositories. to /etc/apt/sources.list

deb squeeze-backports-sloppy main
deb squeeze main contrib non-free
deb squeeze-lts main contrib non-free

After adding it I continued getting missing package errors while trying:

# apt-get update && apt-get install postgresql postgresql-client


E: Some index files failed to download. They have been ignored, or old ones used instead.

Thus I googled a bit and I found the following PostgreSQL instructions working Debian 7.0 Wheeze and decided to try it 1 in 1 just changing the repository package wheezy word with squeeze
in original tutorial postgre's deb repositories are:


deb wheezy-pgdg main

I've only changed that one with:


deb squeeze-pgdg main


I guess though this worked for Debian Squeeze installing current versions such as Debian 8.0 Jessis and newer wouldn't be a prolem if you just change the debian version keyword witht he distribution for which you need the postgresql package

Here is all the consequential steps I took to make the PostgreSQL 9.5 running on my old and unsupported Debian 6.0 Squeeze

Create /etc/apt/sources.list.d/pgdg.list. The distributions are called codename-pgdg. In the example, replace wheezy with the actual distribution you are using:

# vim /etc/apt/sources.list.d/pgdg.list


deb squeeze-pgdg main

debian:~# apt-get –yes install wget ca-certificates debian:~# wget –quiet -O – | sudo apt-key add – debian:~# apt-get update debian:~# apt-get upgrade debian:~# apt-get –yes install postgresql-9.5 pgadmin3

Next step is to connect to PostGreSQL and create database user and a database # su – postgres $ psql

Create a new database user and a database:

postgres=# CREATE USER mypguser WITH PASSWORD 'mypguserpass'; postgres=# CREATE DATABASE mypgdatabase OWNER mypguser;



# createuser mypguser #from regular shell # createdb -O mypguser mypgdatabase

Quit from the database

postgres=# q

Connect as user mypguser to new database

# su – mypguser $ psql mypgdatabase


# psql -d mypgdatabase -U mypguser

If you get errors like:

psql: FATAL: Ident authentication failed for user "mypguser"

edit pg_hba.conf in /etc/postgresql/9.5.Y/main/pg_hba.conf


local all all trust # replace ident or peer with trust

reload postgresql

/etc/init.d/postgresql reload …


To make sure that PostGreSQL is running on the system check the following processes are present on the server:




root@pcfreak:/var/www/images# ps axu|grep -i post postgres 9893 0.0 0.0 318696 16172 ? S 15:20 0:00 /usr/lib/postgresql/9.5/bin/postgres -D /var/lib/postgresql/9.5/main -c config_file=/etc/postgresql/9.5/main/postgresql.conf postgres 9895 0.0 0.0 318696 1768 ? Ss 15:20 0:00 postgres: checkpointer process postgres 9896 0.0 0.0 318696 2700 ? Ss 15:20 0:00 postgres: writer process postgres 9897 0.0 0.0 318696 1708 ? Ss 15:20 0:00 postgres: wal writer process postgres 9898 0.0 0.0 319132 2564 ? Ss 15:20 0:00 postgres: autovacuum launcher process postgres 9899 0.0 0.0 173680 1652 ? Ss 15:20 0:00 postgres: stats collector process root 14117 0.0 0.0 112404 924 pts/1 S+ 16:09 0:00 grep -i post



Well that's all folks now you will have the postgresql running on its default port 5433:


debian:/etc/postgresql/9.5/main# grep -i port postgresql.conf
port = 5433 # (change requires restart)
# supported by the operating system:
# supported by the operating system:
# ERROR REPORTING AND LOGGING # %r = remote host and port



Well that's it folks thanks The Lord Jesus Christ grace by the prayers of John The Baptist and Saint Sergij Radonezhki it works 🙂



Happy Birthday Debian! – Rejoice, Debian GNU / Linux turns 20 :)

Wednesday, August 28th, 2013

Debian Happy birthday cake with debian logo spiral - Debian Linux becomes 20 years old

 A bit outdated news but still worthy to mention as Debian GNU / Linux is important part of my life. On 16 of August this year Debian turned 20 years! I'm actively using Debian Linux for servers and Desktops over the past 13 years and for this time I've seen right before my eyes how debian grow and from buggy hobbyinst Linux distribution became a robust and rock-solid OS. Moreover Debian is now practically the most important Linux distribution around. Thanks to it currently a thousands of other world changing distributions like Ubuntu, Arch Linux, Knoppix Linux LiveCD, Linux Mint etc. Debian is truly multi platform as of time of writting supports 10 hardware architecture (platforms) – in this number Embedded devices like ARM processors, has translation of most shipped software to 73 languages and comes with about 20 000 installable software packages. Contribution of Debian GNU Linux for Free software community is immerse, hundreds of millions or even billion Debian servers or some kind of Debian based OSes are running all around the net. Besides that Debian is one of the largest if not the biggest and most influential Open Source Project. By its essence existing of Debian is just a miracle. 
Though out of date again,  lets great each other with Happy Debian Anniversary and Wish Debian a many and healthy years of successful development!

Alternative way to enter as administrator in MySQL if you forgot MySQL root password on Debian Linux

Wednesday, July 10th, 2013

Forgot MySQL password root alternative way to enter as administrator in MyQL MySQL logo with 2 dolphins

Whether you have to administrate a bunch of chaotic organized MySQL servers and amount of work is more than you can bear it is very common you make stupid mistakes, like loosing MySQL root adminsitrator password. There is way to recover password by stopping SQL server and starting it with –skip-grant-tables options via SSH , however if you do it that way there is at least few seconds of down time and as its not a good idea on productive servers Debian and Ubuntu Linux admins have better way to do it by using MySQL default user used to check whether all is fine with database on MySQL server initialization via /etc/init.d/mysql. User with GRANT PRIVILEGES, (all MySQL administrator users have grant privileges) on Debian based distributions is debian-sys-maint and whether you have root access to server you can easily obtain password with:

# grep -i -E 'user|pass' /etc/mysql/debian.cnf |uniq

user = debian-sys-maint

password = k6x6tBUBfHN3ZxHv

Using this password then you can login via mysql cli or via PhpMyAdmin, whether installed and do any normal SQL operation you do as root. Of course having this password in plain text file can be very dangerous, by default it is configured to be only red by root be careful not to change this permissions by default as anyone who has access to system can then access your SQL as administrator.
To reset MySQL root password once logged in run:

UPDATE USER set password=PASSWORD('NEW_PASS_WORD') where USER='root';

Enjoy 😉

ZenMap Nmap multi platform Graphical frontend for checking port security

Saturday, June 15th, 2013

graphic program to scan remote network server port security on GNU Linux and Windows ZenMap

Recently I wrote little article with some examples for scanning server port security with Nmap. I forgot to mention in the article that there is also Nmap frontend GUI program called ZenMap. ZenMap port is available for both Windows and Linux. In Debian, Ubuntu, Mint and other debian derivative distributions ZenMap is available from standard package repositories;

 noah:~# apt-cache show zenmap|grep -i description -A 3

Description-en: The Network Mapper Front End
 Zenmap is an Nmap frontend. It is meant to be useful for advanced users
 and to make Nmap easy to use by beginners. It was originally derived
 from Umit, an Nmap GUI created as part of the Google Summer of Code.
Description-md5: 4e4e4c6aeaa4441484054473e97b7168
Tag: implemented-in::python, interface::x11, network::scanner, role::program,
 uitoolkit::gtk, use::scanning, x11::application
Section: net

To install  ZenMap on Debian / Ubuntu Linux:

noah:~# apt-get install --yes zenmap

In Fedora, CentOS and other RPM based Linux-es to install ZenMap run:

noah:~# yum -y install nmap-frontend nmap

To use Nmap's Frontend full functionality, you have to run it as (root) superuser:

hipo@noah:~$ sudo su
[sudo] password for hipo:
noah:~# zenmap

Zenmap saves, a lot of time as there is no need to  remember Nmap's arguments or run few Nmap scans until you get essential information for remote scanned machine.
It automatically gives details on Remote server running services (fingerprint)

Zenmap remote server security services scan with services software version

Very useful report it makes as well is network (and host) topology diagram,

network scanner remote host Linux Windows toplogy guess ZenMap screenshot

ZenMap is just Nmap frontend and under the GUI it does use Nmap with various arguments to do produce scan results. In Nmap Output tab, you can see a lot of verbose info.

Zenmap Linux Windows GUI port scanne  nmap output tab screen Debian / Ubuntu Linux

Happy scanning 🙂

Remote Desktop client – Remmina, Connect Remote to MS Windows VNC hosts from Linux

Friday, May 31st, 2013

remmina remote connet to windows linux vnc client logo

If you're system administrator, who use Linux as Desktop. You surely want to check out Remmina – The GTK+ Remote Desktop Client.

As far as I tested among all VNC Linux clients I know Remmina is definitely the one of choice in terms of Interface simplicity / stability and remote connection level of responsibility.

Before finding out about Remmina existence, I tried xtightvncviewer, xvnc4viewer, gvncviewer, gtkvncviewer. xtightvncviewer, xvncviewer and gvncviewer are more for console geeks and hence either they lack GUI interface or user interface looks terrible.

GTKVncViewer's interface is also not bad but still not со nice as Remmina's.

gtkvncviewer Debian GNU Linux Wheezy screenshot Linux VNC simple client

As you see in above shot, gtkvncviewer lacks any configuration. The only thing it can do is connect to remote host and you have option to configure nothing related how remote connection will respond, what type of Resolution to use etc.

I know of of no other Linux VNC Clients that has configurability and GUI interface of Remmina.


As of time of writting Remmina is at stable version 1.0 and supports following Remote connection protocols:

  • VNC
  • VNC
  • RDP
  • RDPF
  • RDPS
  • SFTP
  • SSH

Remmina is available across mostly all Linux mainstream distributions:

To install Remmina on Debian / Ubuntu and deb derivatives:

debian:~# apt-get –yes install remmina

On Redhats (Fedora, CentOS, RHEL – RPM based Linuxes) install via:

[root@centos ~]# yum –yes install remmina

Below are few screenshots of Remmina:

Remmina Linux remote vnc connect best software gui frontend screenshot

Linux VNC best VNC connect tool Remmina preferences screenshot

One of best Remmina feature is it supports Tabbing just like in Firefox. You can open a number of Remote VNC connects to different Windows hosts and manage them all by switching from tab to tab.

Remmina best vnc linux desktop client screenshot with tabs / What is best VNC client for Linux

BSD (Berkley Software Distribituion) use by distribution type (FreeBSD, NetBSD, OpenBSD, DrangflyBSD) use percantage charts

Saturday, February 18th, 2012

I've hit an interesting article in Wikipedia called Comparison of BSD operating systems
The article explains basic difference between different BSD (Berkley Software Distributions) and what is the primary accent of each of the BSD (free software OS) distributions. It also reveals basic details about the history and how each of the BSD's came to existence. I recommend to anyone interested in free software as it is just a great reading for everybody interested in FOSS.

The most interesting part of the wiki thread is a bar chart, provided by BSD Certification Group research conducted in September 2005.

FreeBSD, OpenBSD, NetBSD, Dragonflybsd usage statistics

The above diagram is showing the proportion of users of each BSD variant from the BSD usage survey prior conducted

The research is already 6 years old, and unfortunately as of time of writting seems to be the only publicly available. Though being outdated, I believe generally the bar charts distributions along different BSD variants would be mostly true. The only big difference will be probably in PC-BSD which is not even on the diagram should have outbeaten DragonflyBSD's use. Since there is no public data available for 2012 and the years 2005 – 2012 for the use percantage of each of the BSD distributions, I've thought about a pseudo way to get some general statistics on each of the BSD distributions popularity. The methodology to gather the required statistics comes to simply, type in Google each of the BSD variant "code names" (e.g. freebsd, netbsd, openbsd etc.) and look at the number of results returned. It seems logical the more results distribution keyword searched returns, the bigger the probability of more users to be involved in developing or using the respective BSD variant.

Below you see the results, I've gathered in my quick "google research":

FreeBSD NetBSD OpenBSD BSD variant (users) use diagram based on Google searches of keywords 2012

As you can see in the above data FreeBSD is still probably leading the BSD use, the public interest to OpenBSD – BSD focused on security has significantly grow since the last 6 years. Next it is seen the PC-BSD users base has probably tremendously increased and according to the Google results returned it is probably on a 3rd place by users interest (use?) followed by NetBSD with only 1.47% of all the BSD users. Lastly with only 0.99%, orders Dragonfly BSD which no longer is so popular as a Desktop BSD based OS as it used to be back in 2005.
Again the presented diagram results are based on only on the factor of Google BSD variant popularity and hence shouldn't be consired too trustworthy, still I'm sure it gives a general idea on how used is each of the BSD variants as of Jan 2012.

How to find out all programs bandwidth use with (nethogs) top like utility on Linux

Friday, September 30th, 2011

Just run across across a super nice top like, program for system administrators, its called nethogs and is definitely entering my “l337” admin outfit next to tools like iftop, nettop, ettercap, darkstat htop, iotop etc.

nethogs is ultra easy to use, to get immediately in console statistics about running processes UPLOAD and DOWNLOAD bandwidth consumption just run it:

linux:~# nethogs

Nethogs screenshot on Linux Server with Nginx
Nethogs running on Debian GNU/Linux serving static web content with Nginx

If you need to check what program is using what amount of network bandwidth, you will definitely love this tool. Having information of bandwidth consumption is also viewable partially with iftop, however iftop is unable to track the bandwidth consumption to each process using the network thus it seems nethogs is unique at what it does.

Nethogs supports IPv4 and IPv6 as well as supports network traffic over ppp. The tool is available via package repositories for Debian GNU/Lenny 5 and Debian Squeeze 6.

To install Nethogs on CentOS and Fedora distributions, you will have to install it from source. On CentOS 5.7, latest nethogs which as of time of writting this article is 0.8.0 compiles and installs fine with make && make install commands.

In the manner of thoughts of network bandwidth monitoring, another very handy tool to add extra understanding on what kind of traffic is crossing over a Linux server is jnettop
jnettop shows which hosts/ports is taking up the most network traffic.
It is available for install via apt in Debian 5/6).

Here is a screenshot on jnettop in action:

Jnettop check network traffic in console

To install jnettop on latest Fedoras / CentOS / Slackware Linux it has to be download and compiled from source via jnettop’s official wiki page
I’ve tested jnettop install from source on CentOS release 5.7 and it seems to compile just fine using the usual compile commands:

[root@prizebg jnettop-0.13.0]# ./configure
[root@prizebg jnettop-0.13.0]# make
[root@prizebg jnettop-0.13.0]# make install

If you need to have an idea on the network traffic passing by your Linux server distringuished by tcp/udp/icmp network protocols and services like ssh / ftp / apache, then you will definitely want to take a look at nettop (if of course not familiar with it yet).
Nettop is not provided as a deb package in Debian and Ubuntu, where it is included as rpm for CentOS and presumably Fedora?
Here is a screenshot on nettop network utility in action:

Nettop server traffic division by protocol screenshot
FreeBSD users should be happy to find out that jnettop and nettop are part of the ports tree and the two can be installed straight, however nethogs would not work on FreeBSD, I searched for a utility capable of what Nethogs can, but couldn’t find such.
It seems the only way on FreeBSD to track bandwidth back and from originating process is using a combination of iftop and sockstat utilities. Probably there are other tools which people use to track network traffic to the processes running on a hos and do general network monitoringt, if anyone knows some good tools, please share with me.

How to Split files on Linux FreeBSD, NetBSD and OpenBSD

Sunday, July 31st, 2011

Split large files in pieces Scissors

Did you have the need to sometimes split an SQL extra large files to few pieces in order to be able to later upload it via phpmyadmin?
Did you needed an extra large video or data file to be cut in few pieces in order to transfer it in few pieces over an USB stick?
Or just to give you an another scenario where I sometimes need to have an enormous file let’s say 3G split in few pieces, in order to later read it in vim or mcedit .
I sometimes need to achieve this on FreeBSD and Linux hosts thus I thought it will be helpful to somebody to give a very quick tutorial on the way large files can be cut in pieces on Linux and BSD hosts.

GNU/Linux and FreeBSD are equipped with the split command. The purpose of this command is exactly the cutting of a file to a number of pieces.

On Linux the split command comes by default install to the system with the coreutils package on most Debian (deb) based and Redhat based (rpm) distributions, theerefore Linux’s version of split is GNU/split since it’s part of the GNU Coreutils package. An interesting fact about Linux split is that one of the two programmers who has coded it is Richard Stallman 😉

On BSD Unix split is the AT&T UNIX (BSD) split

In the past splitting files in pieces was much more needed than today, as people used floppy drives to transfer data, though today with the bloom of Internet and the improve of the data carriers transferring even an extra large files from one place to another is a way more trivial task still at many occasions splitting it in pieces is needed.

Even though today splitting file is very rarely required, still there are times when being able to split a file in X number of parts is very much needed.
Maybe the most common use of splitting a file today is necessery when a large SQL file dumps, like let’s say 200 MBytes of info database needs to be moved from ane hosting provider to another one.
Many hosting providers does disallow direct access with standard mySQL client programs to the database directly and only allow a user to connect only via phpMyAdmin or some other web interface like Cpanel to improve data into the SQL or PostgreSQL server.

In such times, having knowledge on the Unix split command is a priceless asset.

Even though on Linux and BSD the code for the split command is not identical and GNU/split and BSD/split has some basic differences, the use of split on both of these Unices is identical.
The way to split a file in few pieces using on both Linux and BSD OSes is being done with one and the same command, here is how:

1. Splitting file in size of 40 mb On Linux

linux:~# split -b 40m SQL-Backup-Data.sql SQL-Backup-Data_split

2. Splitting file in size of 40mb on BSD (FreeBSD, OpenBSD, NetBSD)

freebsd# split -b 40m SQL-Backup-Data.sql SQL-Backup-Data_split

The Second argument the split command takes is actually called a prefix, the prefix is used as a basis name for the creation of the newly generated files cut in pieces file based on SQL-Backup-Data.sql.

As I said identical command will split the SQL-Backup-Data.sql files in a couple of parts which of it will be sized 40 megas.

These command will generate few files output like:

freebsd# ls -1 SQL-Backup-Dat*SQL-Backup-Data.sql

As you see the SQL-Backup-Data.sql with size 200MB is being split in four files each of which is sized 40mbytes.

After the files are transfered to another Linux or BSD host, they can easily be again united in the original file with the command:

linux:~# for i in $(ls -1 SQL-Backup-Data_split*); echo $i >> SQL-Backup-Data.sql

Alternatively in most Unices also using cat should be enough to collect back the pieces into the original file, like so:

freebsd# cat SQL-Backup-Data_split* >> SQL-Backup-Data.sql

Enjoy splitting