Posts Tagged ‘something’

How to configure mutual Apache WebServer SSL authentication – Two Way SSL mutual authentication for better security and stronger encryption

Tuesday, September 12th, 2017


In this post I'm about to explain how to configure Apache Web server for Two Way SSL Authentication alone and how to configure Two Way SSL Authentication for a Certain Domain URL Locations and the mixture of both One Way standar SSL authentication and Two Way Handshake Authentication .

Generally before starting I have to say most Web sites does not require a Mutual SSL  Authentication (the so called Two-Way SSL).

In most configurations Apache Web server is configured for One Way Basic authentication where The Web server authenticates to the Client usuall that's Browser program such as Mozilla  Firefox / Chrome / IE / Epiphany whatever presenting certificate signed by Trustable Certificate Authority such as VeriSign.


The authority then autneticates to the browser that the Installed certificate on the Apache Web Server is trustable and the website is not a fraudulant, that is especially important for websites where sensitive data is being transferred, lets say Banks (Doing Money Transfers online), Hospitals (Transfelling your Medical results data) or purchasing something from, Ebay.Com, PayPal etc.

Once client validates the certificate the communication line gets encrypted based on Public Key, below diagram illustrates this.

Public Ke Cryptography diagram how it works

However in some casis where an additional Security Hardening is required, the Web Server might be configured to require additional certificate so the authentication between Client -> Server doesn't work by certificating with just a Server provided certificate but to work Two Ways, e.g. the Client might be setup to also have a Trusted Authority Certificate and to present it to server and send back this certificate to the Server as well for a mutual authentication and only once the certificate handshake between;

client -> server and server -> client


is confirmed as successful the two could establish a trustable encypted SSL channel over which they can talk securely this is called
Two way SSL Authentication.


1. Configure Two Way SSL Authentication on Apache HTTPD

To be able to configure Two Way SSL Authentication handshake on Apache HTTPD just like with One way standard one, the mod_ssl Apache module have to enabled.

Enabling two-way SSL is usually not done on normal clients but is done with another server acting as client that is using some kind of REST API to connect to the server


The Apache directive used for Mutual Authentication is SSLVerifyClient directive (this is provided by mod_ssl)

the options that SSLVerifyClient receives are:

none: instructs no client Certificate is required
optional: the client is allowed to present a valid certificate but optionally
require: the client is always required to present a valid Certificate for mutual Authenticaton
optional_no_ca: the client is asked to present a valid Certificate however it has to be successfully verified.

In most of Apache configuratoins the 2 ones that are used are either none or require
because optional is reported to not behave properly with some of the web browsers and
optional_no_ca is not restrictive and is usually used just for establishing basic SSL test pages.

At some cases when configuring Apache HTTPD it is required to have a mixture of both One Way and Two Way Authentication, if that is your case the SSLVerifyClient none is to be used inside the virtual host configuration and then include SSLVerifyClient require to each directory (URL) location that requires a client certificate with mutual auth.

Below is an example VirtualHost configuration as a sample:


The SSLVerifyClient directive from mod_ssl dictates whether a client certificate is required for a given location:

<VirtualHost *:443>

SSLVerifyClient none
<Location /whatever_extra_secured_location/dir>
            SSLVerifyClient require


Because earlier in configuration the SSLVerifyClient none is provided, the client will not be doing a Two Way Mutual Authentication for the whole domain but just the selected Location the client certificate will be not requested by the server for a 2 way mutual auth, but only when the client requests the Location setupped resouce a renegotiation will be done and client will be asked to provide certificate for the two way handshake authentication.

Keep in mind that on a busy servers with multitudes of connections this renegotiation might put an extra load on the server and this even can turn into server scaling issue on a high latency networks, because of the multiple client connects. Every new SSL renegotiation is about to assign new session ID and that could have a negative impact on overall performance and could eat you a lot of server memory.
To avoid this often it i suseful to use SSLRenegBufferSize directive which by default is set in Apache 2.2.X to 128 Kilobytes and for multiple connects it might be wise to raise this.

A mutual authentication that is done on a Public Server that is connected to the Internet without any DMZ might be quite dangerous thing as due to to the multiple renegotiations the server might end up easily a victim of Denial of Service (DOS) attack, by multiple connects to the server trying to consume all its memory …
Of course the security is not dependent on how you have done the initial solution design but also on how the Client software that is doing the mutual authentication is written to make the connections to the Web Server.


2. Configure a Mixture of One Way Standard (Basic) SSL Authentication together with Two Way Client Server Handshake SSL Authentication

Below example configuring is instructing Apache Webserver to listen for a mixture of One Way standard Client to browser authentication and once the client browser establishes the session it asks for renegotiation for every location under Main Root / to be be authenticated with a Mutual Two Way Handshake Authentication, then the received connection is proxied by the Reverse Proxy to the end host which is another proxy server listening on the same host on ( or localhost) on port 8080.


<VirtualHost *:8001>
  SSLEngine on
  SSLCertificateFile /etc/ssl/server-cert.pem
  SSLCertificateKeyFile /etc/ssl/private/server-key.pem

  SSLVerifyClient require
  SSLVerifyDepth 10
  SSLCACertificateFile /home/etc/ssl/cacert.pem
  <location />
    Order allow,deny
    allow from all
    SSLRequire (%{SSL_CLIENT_S_DN_CN} eq "clientcn")
  ProxyPass /
  ProxyPassReverse /



3. So what other useful options do we have?

Keep Connections Alive

This is a good option but it may consume significant amount of memory. If Apache is using the prefork MPM (as many Webservers still do instead of Apache Threading), keeping all connections alive means multiple live processes. For example, if Apache has to support 1000 concurrent connections, each process consuming 2.7MB, an additional 2700MB should be considered. This may be of lesser significance when using other MPMs. This option will mitigate the problem but will still require SSL renegotiation when the SSL sessions will time out.

Another better approach in terms of security to the mixture of requirement for both One Side Basic SSL Authentication to a Webserver and Mutual Handshake SSL Auth is just to set different Virtualhosts one or more configuration to serve the One Way SSL authentication and others that are configured just to do the Mutual Two Way Handshake SSL to specified Locations.

4. So what if you need to set-up multiple Virtualhosts with SSL authentication on the Same IP address Apache (SNI) ?


For those who did not hear still since some time Apache Web Server has been rewritten to support SNI (Server Name Indication), SNI is really great feature as it can give to the webserver the ability to serve multiple one and two way handshake authentications on the same IP address. For those older people you might remember earlier before SNI was introduced, in order to support a VirtualHost with SSL encryption authentication the administrator had to configure a separate IP address for each SSL certificate on each different domian name.  

SNI feature can also be used here with both One Way standard Apache SSL auth or Two Way one the only downside of course is SNI could be a performance bottleneck if improperly scaled. Besides that some older browsers are not supporting SNI at all, so possibly for public services SNI is less recommended but it is better to keep-up to the good old way to have a separate IP address for each :443 set upped VirtualHost.
One more note to make here is SNI works by checking the Host Header send by the Client (browser) request
SSL with Virtual Hosts Using SNI.

SNI (Server Name Indication) is a cool feature. Basically it allows multiple virtual hosts with different configurations to listen to the same port. Each virtual host should specify a unique server name identification using the SeverName directive. When accepting connections, Apache will select a virtual host based on the host header that is part of the request (must be set on both HTTP and SSL levels). You can also set one of the virtual hosts as a default to serve clients that don’t support SNI. You should bear in mind that SNI has different support levels in Java. Java 1.7 was the first version to support SNI and therefore it should be a minimum requirement for Java clients.

5. Overall list of useful Options for Mutual Two Way And Basic SSL authentication

Once again the few SSL options for Apache Mutual Handhake Authentication

SSLVerifyClient -> to enable the two-way SSL authentication

SSLVerifyDepth -> to specify the depth of the check if the certificate has an approved CA

SSLCACertificateFile -> the public key that will be used to decrypt the data recieved

SSLRequire -> Allows only requests that satisfy the expression

Below is another real time example for a VirtualHost Apache configuration configured for a Two Way Handshake Mutual Authentication

For the standard One way Authentication you need the following Apache directives


SSLEngine on -> to enable the single way SSL authentication

SSLCertificateFile -> to specify the public certificate that the WebServer will show to the users

SSLCertificateKeyFIle -> to specify the private key that will be used to encrypt the data sent

6. Configuring Mutual Handshake SSL Authentication on Apache 2.4.x

Below guide is focusing on Apache HTTPD 2.2.x nomatter that it can easily be adopted to work on Apache HTTPD 2.4.x branch, if you're planning to do a 2 way handshake auth on 2.4.x I recommend you check SSL / TLS Apache 2.4.x Strong Encryption howto official Apache documentation page.

In meantime here is one working configuration for SSL Mutual Auth handshake for Apache 2.4.x:


<Directory /some-directory/location/html>
    RedirectMatch permanent ^/$ /auth/login.php
    Options -Indexes +FollowSymLinks

    # Anything which matches a Require rule will let us in

    # Make server ask for client certificate, but not insist on it
    SSLVerifyClient optional
    SSLVerifyDepth  2
    SSLOptions      +FakeBasicAuth +StrictRequire

    # Client with appropriate client certificate is OK
        Require ssl-verify-client
        Require expr %{SSL_CLIENT_I_DN_O} eq "Company_O"

    # Set up basic (username/password) authentication
    AuthType Basic
    AuthName "Password credentials"
    AuthBasicProvider file
    AuthUserFile /etc/apache2/htaccess/my.passwd

    # User which is acceptable to basic authentication is OK
    Require valid-user

    # Access from these addresses is OK
    Require ip
    Require ip 10.144.100

Finally to make the new configurations working depending you need to restart Apache Webserver depending on your GNU / Linux / BSD or Windows distro use the respective script to do it.


Share this on

Things to install on newly installed GNU / Linux (My favourite must have Linux text and GUI programs missing in fresh Linux installs)

Thursday, September 7th, 2017


On every next computer I use as a Desktop or Laptop, I install with Debian GNU / Linux I install the following bunch of extra packages in order to turn the computer into a powerful Multimedia, User, Sys Admin army knife tools, A Programmer desktop and Hacker / Penetration Testing security auditting station.

The packages names might vary less or more across various Debian releases and should be similar or the same in Ubuntu / Linux Mint and the rest of Deb based distribtuions.

Also some of the package names might given in the article might change from time of writting this article just like some  already changed in time from a release to release, nomatter that the general list is a collection of packages I have enjoyed for the last 8 years. And I believe anyone who is new to GNU / Linux and  or even some experienced free software users in need of  full featured computer system for remote system administration purposes or general software development and even small entertainment such as Movie Watching or Playing some unsophisticated basic games to kill some time might benefit from the list of programs collected from my experience as a Free Software GNU / Linux users over the last 12 years or so.

So here we go as you might know, once you have a Debian GNU / Linux, first thing to do is to add some extra repositories in /etc/apt/sources.list

For example my debian 9 Stretch sources.list looks like this:

cp -rpf /etc/apt/sources.list /etc/apt/sources.list-bak

vim /etc/apt/sources.list

And delete / substitute everything within with something as following:

deb stretch main non-free
deb-src stretch main

deb stretch-updates main
deb-src stretch-updates main

deb stretch/updates main
deb-src stretch/updates main

deb stretch/updates main contrib
deb-src stretch/updates main contrib

deb stretch contrib

If you're using an older Debian release for example debian 7 or 8, the sources.list codename stretch word should be changed to wheezy for legacy debian 7 or jessie for debian 8, do it respectively for any future or older Deb releases.

Then proceed and update all current installed packages to their latest release with:

apt-get update && apt-get upgrade

If you're running on a very old Debian GNU / Linux release , you might encounter errors from above cmds, if that's your case just follow the online guides and update to a newer still supported Deb release.

Once all this is done assuming you have connected to the internet via LAN network or if on a laptop via Wireless, here are some useful stuff to install especially if you're planning to use your computer effectively in both console and graphics environment.


1. Install some basic packages necessery if you're planning to be using compilers on the freshly installed GNU / linux

apt-get install –yes gcc autoconf build-essential fakeroot devscripts equivs libncurses5-dev g++ make libc6-dev fontconfig gdc

The most notable package here is build-essential it provides the following collection of C / C++ programs on Deb package based distributions Debian / Ubuntu / Mint etc.

  1. libc6-dev – C standard library.
  2. gcc – C compiler.
  3. g++ – C++ compiler.
  4. make – GNU make utility to maintain groups of programs.
  5. dpkg-dev – Debian package development tools.

2. Install w3m lynx elinks text browsers

apt-get install –yes lynx elinks w3m-img w3m

3. Install wireless and networking tools

apt-get install  –yes tcpdump vnstat wpasupplicant wpagui dnsutils

4. Install Network sniffing, penetration testing and network evaluation tools

apt-get install  –yes wireshark nmap zenmap sniffit iptraf iptraf-ng tshark dsniff netsniff-ng netwox netwag sslsniff darkstat kismet netcat ngrep hashcat hydra hydra-gtk ophcrack ophcrack-cli


wiresharkGUI network traffic analyzer

nmapnmap port mapper and security audit tool

zenmapGUI frontend to nmap

sniffitconsole text based basic packet sniffer and monitoring tool very used tool to sniff servers authenticatoins in the past

iptraf-ngNext Generation interactive colorful IP Lan mointor

tsharkanother network traffic analyzer console version

dsniffVarious tools to sniff network traffic for cleartext insecurities

netsniff-ngLinux network packet sniffer toolkit

netwoxProvides more than 200 tools to solve network problems with DNS, FTP, HTTP, IRC, NNTP, SMTP, SNMP, SYSLOG, TELNET, TFTP

netwaggraphical frontend to netwox

sslsniff SSL/TLS man-in-the-middle attack tool

darkstatnetwork traffic analyzer

kismetwireless sniffer and monitor (very useful in the past for sniffing passwords on a Wi-Fi network)

netcatTCP / IP swiss army knife (good tool to listen and connect to local and remote ports)

ngrepgrep like tool for network traffic

hashcatClaims to be world's fastest and most advanced password recovery utility, capable of attacking more than 160 highly optimized hashing algorithms, supports CPU and GPU (using the video card CPU to enhance password cracking speed), also could be used for distributed password cracking

hydra Very fast network logon cracker, supports webforms works with dictionary attacks etc.

hydra-gtkGTK GUI version of Hydra

ophcrackMicrosoft Windows password cracker using rainbow tables GUI

ophcrack-cli Console version of Microsoft Windows password cracker using rainbow tables for speed



5. Install multimedia, entertainment few useful tools and other useful stuff

apt-get install –yes workrave xscreensaver xscreensaver-data xulrunner xutils zenity yelp zgv   tracker-utils alltray ant apt-utils bsdutils  aumix bwidget ca-certificates pulseaudio-module-jack aumix audacious ffmpeg bluefish bluefish-plugins blender blueman bluez cabextract bluez-firmware bsdmainutils dcraw dmidecode evtest file fonts-liberation fonts-stix fonts-uralic fonts-opensymbol fonts-lyx fonts-cantarell fuse gimp gimp-data-extras gimp-plugin-registry git gnupg gnupg2 imagemagick imwheel inkscape iw less 

bsdutils – Provides some nice old school programs such as :


wall – a program to write to every logged in user console, used in old times on time sharing servers to notify all users about sys admin planning for a reboot or for some other update activity

renice – allows to renice priority over already prioritized process with (nice command)

script – Allows you to do a recorder like saves of user activity on a console / terminal

logger – send logging output from programs to syslog 


alltray – A small program that allows you to bring to dock any program useful to make Thunderbird appear in Gnome / Mate / KDE Dock in a similar manner as Outlook does in m$ Windows

zgv – SVGAlib graphical (picture viewer) useful to view pictures from tty consoles

zenity – allows to display graphical dialog boxes by using shell scripts

aumix – Simple text based mixer control, useful to tune up sound values and mic recording volume from console

WorkRave – is a useful program to periodically remind you to stand out of the computer on a specified interval and shows you graphically some exercies to do to prevent your physical health to not deteriorate by standing all day immobilized

Bluefish – Is Advanced GTK+ HTML Editor useful if you're about to edit HTML / CSS and other Web files

dcraw – Decode raw digital images

dmidecode – Text program that reports your computer hardware

blueman, bluez – Programs to enable USB support on your Linux

evtest – evtest is a utility to monitor Linux input devices

file – little tool to determine file type based on "magic numbes"

fontsliberation – Fonts with same metrics as Times, Arial and Courier

6. Install Text based console Multimedia Mp3 / Mod / S3m players

apt-get install –yes mpg321 mpg123 cmus mp3blaster mplayer sox  ogg123 mikmod cplay cdcd cdck eject


mpg321, mpg123 Mp3 and Ogg Vorbis console player historically one of the earliest I used to play my music

cmus Another awesome ncurses menu based small music player

mp3blaster Full Screen ncurses text console mp3 and Ogg vorbis music player

mplayer An awesome old school (the defacto standard) and still one of the best Music and Video player for GNU / Linux

sox Swiss army knife of sound processing, contains (sox, play, rec and soxi commands), which could be used to play, rec and add effects to WAV and other popular old sound formats

ogg123 Play Ogg Vorbis .OGG Free encoding file format in console

mikmodThe most famous Tracker (S3M, MOD, IT) music player for *NIX, play the old soundtracker formats on your GNU / Linux

cplay – A really nice text front end to music players, the cool thing about it it shows how much is left for the song to over using ASCII

cdcd – play Audio CDs from console

eject – eject your CD Drive from console

cdck – tool to verify the quality of written CDs/DVDs


7. Install Games

apt-get install –yes xpenguins frozen-bubble alex4 bsdgames bb ninvaders blobwars btanks chromium-bsu criticalmass figlet freetennis njam swell-foop dreamchess extremetuxracer gltron gnuchess wesnoth njam wing nikwi dreamchess gltron gnome-games swell-foop aisleriot prboom


xpenguins – little penguins walk on your screen great to use as a screensaver

frozen-bubble – cool game with bubbles you have to pop out

blobwars – platform shooting game

njam – pacman like game with multiplayer support

extremetuxracer – 3D racing game featuring Tux the Linux penguin mascot

gltron – 3D remake of the good well known Tron Game

gnuchess – GNU remake of classic Chess game

wing – arcade Galaga like game for GNU / Linux

wesnoth – Fantasy turne based strategy game

dremachess – 3D chess game

swell-fool – Colored ball puzzle game

gnome-games – A collection of Games for the GNOME Desktop

nikwi – platform game with a goal to collect candies

aisleriot – GNOME solitaire card game 

prboom – PrBoom, a remake of the Doom 3d shooter classic game using SDL (supports OpenGL), to play it you will need WAD files if you don't have it install (doom-wad-shareware) package

figlet – Make large character ASCII banners out of ordinary provided text (just provide any text and get a nice ASCII picture out of it)


8. Install basic archivers such as rar, zip, arj etc.

apt-get install –yes zip unrar arj cpio p7zip unzip bzip2 file-roller


cpioGNU cpio, a program to manager archive files

bzip2BunZip2 block compressor decompressor utility (necessery to untar the .tar.bz2 tar balls)

unzipDe-archiver for .zip files console version

rar, unrarArchiver Unarchiver for .rar files in terminal / console (unfortunately non-free software)

file-rollerArchive manager for gnome


If you're looking for an advanced file archive, dearchive software GUI that be a substitute for Windows WinRar,  WinZip there is also the proprietary software PeaZip for Linux, as I stay as much as possible away from non-free software I don't use PeaZip though. For me file-roller's default GNOME archiver / unarchiver does a pretty good job and if it fails someties I use the console versions of above programs

9. Install text and speech synthesizer festival freetts

apt-get install –yes festival festival-cmu festvox-kallpc16k festvox-ru mbrola-en1 speech-dispatcher-festival freetts flite yasr


FestivalIs the general multi-lingual speech synthesis system

yasris a basic console screen reader program

flitea small run time speech synthesis engine alternative to festival, another free software synthesis tool based built using FestVox


Festival is great if you want to listen to text files and can easily be used to convert basic PDFs or DOC files to listen them if you're lazy to read I've explained on how you can use festival to read speak for you PDFs and DOCs, ODF (Open Document Format) here

10. Install linux-header files for latest installed Debian kernel

apt-get install –yes linux-headers-$(uname -r)

You will need that package if you need to compile external usually DRM (Digital Rights Management)  external modules that could be loaded to current Debian precompiled kernel, I recommend you abstain from it since most of the modules are DRMed and doesn't respect your freedom.

11. Install GUI programs and browsers

apt-get install –yes gnome-themes-standard gnome-themes-standard-data epiphany-browser dconf-tools gnome-tweak-tool

epiphany-browserIntuitive GNOME web browser (I love this browser, though sometimes Crashing I prefer to use it as it is really fast and lightweight I think Mac OS's Safari has been partially based on its programming code)

dconf-tools Dconf is a low-level key / value database designed for storing desktop environment variables (provides dconf-editor – which allows you to tune tons of gnome settings tunable only through this database it is something like Windows regedit registry editor tool but for GNOME)

gnome-themes-standard / gnome-themes-standard-data The name says it all it provides beautiful gnome standard themes

gnome-tweak-tool Graphic tool to adjust many advanced configuration settings in GNOME in GNOME 3.2, many of the old GNOME 3.0 and 2.X capabilities such as Desktop icons or Computer on the Desktop and many more useful gnome capabilities you might be used for historically can be enabled through that handy tool, it is a must for the GNOME user

12. Install text and GUI mail clients

apt-get install –yes mutt fetchmail bsd-mailx mailutils thunderbird aspell-bg aspell-en aspell-ru

I use primary 3 languages Russian, Bulgarian and English, so by installing the 3 packages aspell-bg, aspell-en, aspell-ru, that would add a possiility for Thunderbird and LibreOffice to have ability to spell check your mails and ODF documents, if your native language is different or you speak different languages do run:

apt-cache search aspell 

And install whatever languages spell check support you need


13. Install filesystem mount, check and repair tools

apt-get install –yes ntfs-3g sshfs dosfstools ext3grep  e2fsprogs e2fsck-static growisofs  e2undel extundelete recover bleachbit


ntfs-3g – read / write NTFS driver support for FUSE (Filesystem in UserSpace) or in other words install these to be able to mount in read/write mode NTFS filesystems

sshfs – filesystem client based on SSH File Transfer Protocol, that little nitty tool enables you to mount remotely SSH Filesystems to your local Linux Desktop, it is also useful to install across servers if you need to remotely mount SSH Filesystems

e2fsprogs ext2 / ext3 / ext4 filesystem utilities to check, fix, tune, defragment resize and create etc. new filesystems  (provides crucial commands such as fsck.ext2, fsck.ext3, fsck.ext4, e2label, lsattr, chattr, resize2fs, mkfs.ext2, mkfs.ext3, mkfs.ext4 …)

dosfstoolstool giving you ability to check, create and diagnose DOS and Windows FAT 32 Filesystems provides commands such as dosfsck, mkdosfs, dosfslabel, fsck.msdos, fsck.vfat, mkfs.msdos

growisofs DVD+ RW / Read Only Recorder

ext3greptool to help recover deleted files on ext3 filesystems

e2undel Undelete utility for ext2 filesystems

14. Install emulators for PC OS Emuation (Qemu), DOS and Wine to run native Windows programs on GNU / Linux

apt-get install –yes qemu qemu-utils aqemu dosbox mame mame-extra os8 simh wine nestopia dgen


QemuVirtual Machine emulator with support UEFI firmware

Aqemu – Qemu QT VM GUI Frotend

Dosbox – Dos Emulator, great to have to play the good old DOS games on your GNU / Linux

Mame – Multiple Arcade Machine Emulator, great if you want to play the old arcade games of your youth such as The Punisher, Cadillacs and Dinosaurs, Captain America, Robocop, Captain Commando, Wonderboy and so on the list goes on and on …

simh – PDP-1 PDP-4 PDP-7, PDP-9, PDP-10, PDP-11, PDP-15 HP 2100, IBM System 3, IBM 1620, Interdata, SDS, LGP-21, LGP-30, DEC VaX emulator

nestopia Nintendo Entertainment System / Famicom Emulator

dgen – Sega MegaDrive GNU / Linux Emulator


15. Install Network Time protocol daemon and ntpdate (time synchronizing text client)

apt-get install –yes ntpdate ntp

16. Install Djview and CHM books reader

apt-get install –yes djview djview4 djvulibre-bin xchm kchmviewer chm2pdf

Install this packages to be able read DjView and CHM book formats

17. Install other text stuff

# Install text calculator I always prefer and use this console tool instead of the GUI gnome-calculator

apt-get install –yes bc

18. Install printing CUPs and printing utilities

apt-get install –yes cups-client cups-daemon cups-server-common hplip hplip-data printer-driver-hpcups printer-driver-hpijs ghostscript 

A bunch of packages for your Linux Deskto po properly support printing, you might need to install some extra packages depending on the type of printer you need to use, perhaps you will have to take few minutes probably to configure CUPs.

19. Install text monitoring tools

apt-get install –yes htop atop  dnstop  iftop iotop  jnettop ntopng  pktstat  powertop  sntop mariadb-client  iotop  itop jnettop kerneltop logtop
pgtop powertop


htop – More interactive colorful process viewer similar to top

atop – Monitor for system resources and process activity

dnstop – Console tool for analyze DNS traffic

iftop displays bandwidth usage information on a chosen network interface

iotopsimple top-like I/O (I / O) information output by the Linux kernel

jnettopView hosts / ports taking up the most network traffic

ntopng High-Speed Web-based Traffic analysis and Flow Collection tool

pktstat top like utility for network connections usage

powertop tool to diagnose issues with power consumption and management (useful for Linux running laptops)

sntop A ncurses-based utility that polls hosts to determine connectivity

mariadb-clientthis is the new name for the old mytop / mtop MySQL top package

kerneltop shows Linux kernel usage in a style like top

pgtop Show PostgreSQL queries in a top like style

lograte real time log line rate analyzer


20. Install text command line tools for transferring data from Web sites and FTP

apt-get install –yes curl wget lftp filezilla gftp transmission linuxdcpp

curl command line tool for transferring data with URL syntax

wget tool to retrvie files and html from the web

lftp sophisticated command-line FTP/HTTP/BitTorrent client program

filezilla Full-featured graphical FTP/FTPS/SFTP client

gftp X/GTK+ and console FTP client

transmission lightweight Bittorrent client

linuxdcpp – Port of the Windows file-sharing program DC++


21. Install text based communication programs

apt-get install –yes irssi freetalk centerim finch


Irssi Great console IRC chat client with support for encryption

FreeTalk console based jabber client

centerim Console based ICQ client

finch – Multi protocol Text console client for AIM/ICQ, Yahoo!, MSN, IRC, Jabber / XMPP / Google Talk Sametime, MySpaceIM, Napster, Zephyr, Gadu-Gadu, Bonjour, GroupWise


22. Install Apache Webserver and MySQL

This two are necessery if you're about to use your computer as a PHP / MySQL develment station

apt-get install mysql-server phpmyadmin apache2 libapache2-mod-php5 php-pear php5 php5-mysql  ant ant-contrib apache2-dev apache2-ssl-dev


mysql-server MySQL community edition

ant Java based build tool like make (necessery for building many third party apache modules and code)

libapache2-mod-php5the php module loaded into apache

phpmyadminWebtool admin to manage your MySQL database


23. Install mouse support for consoles

apt-get install –yes gpm


gpm is the general purpose mouse interface, if you want to have support for your mouse in TTY consoles (the ones you go to with CTRL + ALT + F2, CTRL + ALT + F3 and so on install it).


24. Install various formats converter tools

apt-get install –yes html2text pdf2djvu unoconv oggconvert webkit2pdf img2pdf gsscan2pdf netpbm dir2ogg soundconverter


gsscan2pdfGUI program to produce PDF or DJVU from scanned documents

img2pdfLossless conversion of raster images to PDF

webkit2pdfexport web pages to PDF files or printer

html2textAdvanced HTML to text converter

oggcconvert – convert media files to free format 

netpbmGraphics conversion tools between image formats

dir2ogg – converts MP3, M4A, WMA, FLAC, WAV files and Audio CDs to the open-source OGG format.

soundconverter – GNOME application to convert audio files into other formats


There are probably a lot of more handy packages that other Free Software users like to install to make the GNU / Linux desktop notebook even more entertaining and fulfillful for daily work. If you can think of other useful packages not mentioned here you tend to use on a daily basis no matter where Debian based or other distro, please share that would help me too to learn a new thing and I'll be greateful.

Enjoy !

Share this on

Migrate Webserver and SQL data from old SATA Hard drive to SSD to boost websites performance / Installing new SSD KINGSTON 120GB hard disk on Linux

Monday, March 28th, 2016

Blog and websites hosted on a server were giving bad performance lately and the old SATA Hard Disk on the Lenovo Edge server seemed to be overloaded from In/Out operations and thus slowing down the websites opeining time as well as SQL queries (especially the ones from Related Posts WordPress plugin was quite slow. Sometimes my blog site opening times were up to 8-10 seconds.

To deal with the issue I obviously needed a better speed of I/O of hard drive thus as I've never used SSD hard drives so far,  I decided to buy a new SSD (Solid State Drive) KINGSTON SV300S37A120G, 605ABBF2, max UDMA/133  hard disk.
Mounting the hard disk physically on the computer tower case wasn't a big deal as there are no rotating elements of the SSD it doesn't really matter how it is mounted main thing is that it is being hooked up somewhere to the case.

I was not sure whether the SSD HDD is supported by my Debian GNU / Linux so I had see whether Linux Operating System has properly detected your hard disk use dmesg

1. Check if SSD Hard drive is supported in Linux


linux:~# dmesg|grep -i kingston
[    1.182734] ata5.00: ATA-8: KINGSTON SV300S37A120G, 605ABBF2, max UDMA/133
[    1.203825] scsi 4:0:0:0: Direct-Access     ATA      KINGSTON SV300S3 605A PQ: 0 ANSI: 5


linux:~# dmesg|grep -i sdb
[    1.207819] sd 4:0:0:0: [sdb] 234441648 512-byte logical blocks: (120 GB/111 GiB)
[    1.207847] sd 4:0:0:0: [sdb] Write Protect is off
[    1.207848] sd 4:0:0:0: [sdb] Mode Sense: 00 3a 00 00
[    1.207860] sd 4:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[    1.207928]  sdb: unknown partition table
[    1.208319] sd 4:0:0:0: [sdb] Attached SCSI disk


Well great news as you see from above output obviously the Kingston SSD HDD was detected by the kernel.
I've also inspected whether the proper dimensions of hard drive (all 120 Gigabytes are being detected by the OS):


linux:~# fdisk -l /dev/sdb
Disk /dev/sdb: 120.0 GB, 120034123776 bytes
255 heads, 63 sectors/track, 14593 cylinders, total 234441648 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: 0x00000000

Even better as the proper HDD sizing was detected by Linux kernel.
Next thing to do was of course to create ext4 filesystem on the SSD HDD.
I wanted to give 2 separate partitions for my Webserver Websites DocumentRoot directories which all lay under the standard Apache location inside /var/www as well as MySQL data folder which is also under the standard Debian based Linuces – /var/lib/mysql as the SQL data directory was just 3.3 GB size, I've decided to reserve 20GB gigabytes for the MySQL and another 100 GB for my PHP / CSS / JS / HTML and other data files /var/www.

2. Create SSD partitions with cfdisk

Hence I needed to create:

1. SSD partition of 100GB
2. SSD partition of 20GB

I have cfdisk installed and I believe, the easiest way to create the partitions is using interactive partitioner as CFDISK instead of fdisk: so in order to make the proper partitions I've ran


linux:~# cfdisk /dev/sdb

I' will skip explainig details on how to use CFDISK as it is pretty standard – display or manipulate disk partition table tool.
Just press on NEW button (moving with arrow keys buttons) and choose the 2 partitions size 100000 and 20000 MB (one thing to note here is that you have to choose between Primary and  Logical creation of partitions, as my SSD is a secondary drive and I already have a ) and then press the
WRITE button to save all the partition changes.

!!! Be very careful here as you might break up your other disks data make sure you're really modifying the SSD Hard Drive and not your other /dev/sda or other attached external Hard drive or ATA / SATA disk.
Press the WRITE button only once you're absolutely sure, you do it at your own (always create backup of your other data and don't blame me if something goes wrong) …

Once created the two partitions will look like in the screenshot below:


3. Create ext4 filesystem 100 and 20 GB partitions

Next thing to do before the two partitions are ready to mount under Webserver's files documentroot /var/www and /var/lib/mysql is to create ext4 filesystem, though some might prefer to stick to ext3 or reiserfs partition, I would recommend you use ext4 for the reason ext4 according to my quick research is said to perform much better with SSD Hard Drives.

The tool to create the ext4 filesystems is mkfs4.ext4 it is provided by debian package e2fsprogs I have it already installed on my server, if you don't have it just go on and install it with:

linux:~# apt-get install –yes e2fsprogs


To create the two ext4 partitions run:

linux:~# mkfs4.ext4 /dev/sdb5


linux:~# mfs4.ext4 /dev/sdb6

Here the EXT4 filesystem on partition that is supposed to be 100 Gigabytes will take 2, 3 minutes as the dimensions of partition are a bit bigger, so if you don't want to get boring go grab a coffee, once the partitions are ready you can evaluate whether everyhing is properly created with fdisk you should get output like the one below


linux:~# fdisk -l /dev/sdb
Disk /dev/sdb: 120.0 GB, 120034123776 bytes
255 heads, 63 sectors/track, 14593 cylinders, total 234441648 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: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1              63   234441647   117220792+   5  Extended
/dev/sdb5             126    39070079    19534977   83  Linux
/dev/sdb6        39070143   234441647    97685752+  83  Linux


4. Mount newly created SSD partitions under /var/www and /var/lib/mysql

Before I mounted /var/www and /var/lib/mysql in order to be able to mount under the already existing directories I had to:

1. Stop Apache and MySQL server
2. Move Mysql and Apache Documentroot and Data directories to -bak
3. Create new empty /var/www and /var/lib/mysql direcotries
4. Copy backpups ( /var/www-bak and /var/lib/mysql-bak ) to the newly mounted ext4 SSD partitions

To achieve that I had to issue following commands:

linux:~# /etc/init.d/apache2 stop
linux:~# /etc/init.d/mysql stop

linux:~# mv /var/www /var/www-bak
linux:~# mv /var/lib/mysql /var/lib/mysql-bak

linux:~# mkdir /var/www
linux:~# mkdir /var/lib/mysql
linux:~# chown -R mysql:mysql /var/lib/mysql

Then to manually mount the SSD partitions:

linux:~# mount  /dev/sdb5 /var/lib/mysql
linux:~# mount /dev/sdb6 /var/www

To check that the folders are mount into the SSD drive, ran mount cmd:


linux:~# mount
/dev/sda1 on / type ext3 (rw,errors=remount-ro)
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
udev on /dev type tmpfs (rw,mode=0755)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=620)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
/dev/sdc1 on /backups type ext4 (rw)
/dev/sdb5 on /var/lib/mysql type ext4 (rw,relatime,discard,data=ordered))
/dev/sdb6 on /var/www type ext4 (rw,relatime,discard,data=ordered))


That's great now the filesystem mounts fine, however as it an SSD drive and SSD drives are being famous for having a number of limited writes on disk before the drive lifetime is over it is a good idea to increase a bit the lifetime of the SSD by mounting the SSD partitions with noatime and errors=remount-ro (in order to not log file access times to filesystem table and to remount the FS read only in case of some physical errors of the drive).

5. Configure SSD partitions to boot every time Linux reboots

Now great, the filesystems gets mounted fine so next thing to do is to make it automatically mount every time the Linux OS boots up, this on GNU / Linux is done through /etc/fstab, for my 2 ext4 partitions this is the content to add at the end of /etc/fstab:


/dev/sdb5               /var/lib/mysql      ext4        noatime,errors=remount-ro       0       1
/dev/sdb6               /var/www        ext4    noatime,errors=remount-ro       0       1


quickest way to add it without a text editor is to echo to the end of file:

linux:~# cp -rpf /etc/fstab /etc/fstab.bak_25_03_2016
linux:~# echo ' /dev/sdb5               /var/lib/mysql      ext4        noatime,errors=remount-ro,discard       0       1' >> /etc/fstab
linux:~# echo ' /dev/sdb6               /var/www        ext4    noatime,errors=remount-ro,discard       0       1 ' >> /etc/fstab

Then mount again all the filesystems including the 2 new created SSD (100 and 20 GB) partitions:

linux:~# umount /var/www
linux:~# umount /var/lib/mysql
linux:~# mount -a

To assure properly mounted with noatime and remount-ro on errors options:

linux:~# mount | grep -i sdb
/dev/sdb5 on /var/lib/mysql type ext4 (rw,noatime,errors=remount-ro)
/dev/sdb6 on /var/www type ext4 (rw,noatime,errors=remount-ro)


It is also a good idea to check a statistics of disk free command:

linux:~# df -h|grep -i sdb
/dev/sdb5         19G  0G    19G  0% /var/lib/mysql
/dev/sdb6         92G   0G    92G  0% /var/www

6. Copy all Webserver and SQL data from backupped directories to new SSD mounted

Last but not least is to copy all original content files from /var/www-bak and /var/lib/mysql-bak to the new freshly  created SSD partitions, though copying the files can be made with normal linux copy command (cp),
I personally prefer rsync because rsync is much quicker and more efficient in copying large amount of files in my case this were 48 Gigabytes.

To copy files from with rsync:


linux:~# rsync -av –log-file /var/log/backup.log  /var/www-bak /var/www
linux:~# rsync -av –log-file /var/log/backup.log  /var/lib/mysql-bak /var/lib/mysql

Then ofcourse, finally to restore my websites normal operation I had to bring up the Apache Webservers and MySQL service


linux:~# /etc/init.d/apache2 start
linux:~# /etc/init.d/mysql start

7. Optimizing SSD performance with periodic trim (discard of unused blocks on a mounted filesystem)

As I digged deeper into how to even further optimize SSD drive performance I learned about the cleaning action TRIM of the partitions for a long term performance proper operation, to understand it better think about trimming like Windows degrament operatin.

fstrim – discard unused blocks on a mounted filesystem

fstrim [-o offset] [-l length] [-m minimum-free-extent] [-v] mountpoint

fstrim is used on a mounted filesystem to discard (or "trim") blocks which are not in use by the filesystem. This is useful for
solid-state drives (SSDs) and thinly-provisioned storage.

By default, fstrim will discard all unused blocks in the filesystem. Options may be used to modify this behavior based on range or
size, as explained below.

Trimming is really necessery, otherwise SSD become very slow after some time. All modern SSD's support TRIM, but older SSD's from before 2010 usually don't.
Thus for an older SSD you'll want to check this on the website of the manufacturer.

As I mentioned earlier TRIM is not supported by all SSD drives, to check whether TRIM is supported by SSD:

linux:~# hdparm -I /dev/sdb|grep -i -E 'trim|discard'
                  *          Data set Management TRIM supported (limit 1 block)

It's easiest to let the system perform an automatic TRIM. That can be done in several ways.

The quickest way for trimming is to place into /etc/rc.local trim  commands, in my case it was the following commands:


fstrim -v /var/lib/mysql
fstrim -v /var/www

To add it I've used my favourite vim text editor.
Adding commands to rc.local will make SSD trimming be executed at boot time so this will reduce a bit the downtime during the trim with some time so perhaps for those like me which are running a crually important websites a better

An alternative way is to schedule a daily cron job to do just place a new job in /etc/cron.daily/trim e.g.:

linux:~# vim /etc/cron.daily/trim


fstrim -v /var/lib/mysql
fstrim -v /var/www

linux:~# chmod +x /etc/cron.daily/trim

However the best way to enable automatic trimming to SSD  is to just add the discard parameter to /etc/fstab I've already done that earlier in this article.

Not really surprising the increase of websites opening (page load times) were decreased dramatically web page loading waiting time fall down 2 to 2.5 times, so the moral of story for me is always when possible from now on to use SSD in order to have superb websites opening times.

To sum it up what was achieved with moving my data into SSD Drive, before moving websites and SQL data to SSD drive the websites were opening for 6 to 10 seconds now sites open in 2 to 4.5 seconds which is below 5 seconds (the normal waiting time for a user to see your website).
By the way it should be not a news forfor people that are into Search Engine Optimization but might be for some of unexperienced new Admins and Webmasters that, all that all page opening times that  exceeds 5 secs is considered to be a slow website (and therefore perhaps not worthy to read).
The high load page times >5 secs makes the website also less interesting not only for end users but also for search engines (Google / Yahoo / Bing / Baidoo etc.) will is said to crawl it less if website is slow.
Search Engines are said to Index much better and crawl more frequently into more responsive websites.
Hence implementing SSD to a server and decreasing the page load time should bring up my visitors stats a bit too.

Well that's all for today, hope you enjoyed 🙂

Share this on

Mount remote Linux SSHFS Filesystem harddisk on Windows Explorer SWISH SSHFS file mounter and a short evaluation on what is available to copy files to SSHFS from Windows PC

Monday, February 22nd, 2016


I'm forced to use Windows on my workbook and I found it really irritating, that I can't easily share files in a DropBox, Google Drive, MS OneDrive, Amazon Storage or other cloud-storage free remote service. etc.
I don't want to use DropBox like non self-hosted Data storage because I want to keep my data private and therefore the only and best option for me was to make possible share my Linux harddisk storage
dir remotely to the Windows notebook.

I didn't wanted to setup some complex environment such as Samba Share Server (which used to be often a common option to share file from Linux server to Windows), neither wanted to bother with  installing FTP service and bother with FTP clients, or configuring some other complex stuff such as WebDav – which BTW is an accepted and heavily used solution across corporate clients to access read / write files on a remote Linux servers.
Hence, I made a quick research what else besides could be used to easily share files and data from Windows PC / notebook to a home brew or professional hosting Linux server.

It turned out, there are few of softwares that gives a similar possibility for a home lan small network Linux / Windows hybrid network users such, here is few of the many:

  • SyncThingSyncthing is an open-source file synchronization client/server application, written in Go, implementing its own, equally free Block Exchange Protocol. The source code's content-management repository is hosted on GitHub







  • OwnCloud – ownCloud provides universal access to your files via the web, your computer or your mobile devices







  • Seafile – Seafile is a file hosting software system. Files are stored on a central server and can be synchronized with personal computers and mobile devices via the Seafile client. Files can also be accessed via the server's web interface


I've checked all of them and give a quick try of Syncthing which is really easy to start, just download the binary launch it and configure it under https://Localhost:8385 URL from a browser on the Linux server.
Syncthing seemed to be nice and easy to configure solution to be able to Sync files between Server A (Windows) and Server B(Linux) and guess many would enjoy it, if you want to give it a try you can follow this short install syncthing article.
However what I didsliked in both SyncThing and OwnCloud and Seafile and all of the other Sync file solutions was, they only supported synchronization via web and didn't seemed to have a Windows Explorer integration and did required
the server to run more services, posing another security hole in the system as such third party softwares are not easily to update and maintain.

Because of that finally after rethinking about some other ways to copy files to a locally mounted Sync directory from the Linux server, I've decided to give SSHFS a try. Mounting SSHFS between two Linux / UNIX hosts is
quite easy task with SSHFS tool

In Windows however the only way I know to transfer files to Linux via SSHFS was with WinSCP client and other SCP clients as well as the experimental:

As well as few others such as ExpandDrive, Netdrive, Dokan SSHFS (mirrored for download here)
I should say that I first decided to try copying few dozen of Gigabyte movies, text, books etc. using WinSCP direct connection, but after getting a couple of timeouts I was tired of WinSCP and decided to look for better way to copy to remote Linux SSHFS.
However the best solution I found after a bit of extensive turned to be:

SWISH – Easy SFTP for Windows

Swish is very straight forward to configure compared to all of them you download the .exe which as of time of writting is at version 0.8.0 install on the PC and right in My Computer you will get a New Device called Swish next to your local and remote drives C:/ D:/ , USBs etc.


As you see in below screenshot two new non-standard buttons will Appear in Windows Explorer that lets you configure SWISH


Next and final step before you have the SSHFS remote Linux filesystem visible on Windows Xp / 7 / 8 / 10 is to fill in remote Linux hostname address (or even better fill in IP to get rid of possible DNS issues), UserName (UserID) and Direcory to mount.


Then you will see the SSHFS moutned:


You will be asked to accept the SSH host-key as it used to be unknown so far


That's it now you will see straight into Windows Explorer the remote Linux SSHFS mounted:


Once setupped a Swish connection to copy files directly to it you can use the Send to Embedded Windows dialog, as in below screenshot


The only 3 problem with SWISH are:

1. It doesn't support Save password, so on every Windows PC reboot when you want to connect to remote Linux SSHFS, you will have to retype remote login user pass.
Fron security stand point this is not such a bad thing, but it is a bit irritating to everytime type the password without an option to save permanently.
The good thing here is you can use Launch Key Agent
as visible in above screenshot and set in Putty Key Agent your remote host SSH key so the passwordless login will work without any authentication at
all however, this might open a security hole if your Win PC gets infected by virus, which might delete something on remote mounted SSHFS filesystem so I personally prefer to retype password on every boot.

2. it is a bit slow so if you're planning to Transfer large amounts of Data as hundreds of megabytes, expect a very slow transfer rate, even in a Local  10Mbit Network to transfer 20 – 30 GB of data, it took me about 2-3 hours or so.
SWISH is not actively supported and it doesn't have new release since 20th of June 2013, but for the general work I need it is just perfect, as I don't tent to be Synchronizing Dozens of Gigabytes all the time between my notebook PC and the Linux server.

3. If you don't use the established mounted connection for a while or your computer goes to sleep mode after recovering your connection to remote Linux HDD if opened in Windows File Explorer will probably be dead and you will have to re-enable it.

For Mac OS X users who want to mount / attach remote directory from a Linux partitions should look in fuguA Mac OS X SFTP, SCP and SSH Frontend

I'll be glad to hear from people on other good ways to achieve same results as with SWISH but have a better copy speed while using SSHFS.

Share this on

Fix “Secure Connection Failed” – An error occured SSL received a record that exceeded the maximum permissible length howto

Monday, September 14th, 2015

When I was trying to establish a new Internal Business SSL certificate on one of the 6 months planned SPLIT projects (e.g. duplicate a range systems environment to another one), I've stumbled a very odd SSL issue. Once I've setup all the virtualhost SSL configurations properly (identical SSL configuration directives and Apache Webserver version to another host and testing in a browser I was getting the following error:

Secure Connection Failed

An error occurred during a connection to

SSL received a record that exceeded the maximum permissible length.

(Error code: ssl_error_rx_record_too_long)

Below is a screenshot:

The page you are trying to view can not be shown because the authenticity of the received data could not be verified. Please contact the web site owners to inform them of this problem. Alternatively, use the command found in the help menu to report this broken site.

The first logical thing to do was to check the error.log but there was no any errors there that point me to anything meaningful, besides that the queries I was making to the Domain doesn't show off as requests neither in Apache access.log nor in error.log so this was puzzling.
I thought I might have messed up something during Key file / CSR generation time so I revoked old certificate and reissued it.


$ openssl x509 -text -in |less ertificate: Data: Version: 3 (0x2) Serial Number:

Shows that all is fine with certificate Then when trying to test remote certificate with SSL command:


openssl s_client -CApath -connect

: There was an error After plenty of research in Google I come to conclusion something is either wrong with Listen httpd.conf directive or NameVirtualHost is binded to port 80 or some other port different from 443, however surprisingly I did not used the NameVirtualHost at all in my apache config. After a lot of pondering I finally spot it. The whole certificate isseus were caused by:

< – Less than sign

which I missaw and forget to clean up from template during IP paste (obtained from /sbin/ifconfig |grep -i xx.xx.xx.xx). So finally in order to fix the SSL error I had to just delete <, e.g.:

<VirtualHost <>

had to become:



Such a minor thing took me 3 hours of pondering to resolve and thanksfully it is finally fixed! Then of course had to restart Apache to make fixed Vhost settings working:

# apachectl stop; sleep 2; apachectl start

So now the SSL works again, thanks God!

Share this on

Sunday of the Blind in Orthodox Church, 6th week after Easter (Passover)

Monday, May 18th, 2015





This Sunday I was to Church and part of our Gospel Reading that occurs on every Holy Liturgy in the Orthodox Church this time we had the following reading:

Gospel of John Jesus Heals the Man Born Blind

1 And as Jesus passed by, he saw a man which was blind from his birth.
2 And his disciples asked him, saying, Master, who did sin, this man, or his parents, that he was born blind?
3 Jesus answered, Neither hath this man sinned, nor his parents: but that the works of God should be made manifest in him.
4 I must work the works of him that sent me, while it is day: the night cometh, when no man can work.
5 As long as I am in the world, I am the light of the world.
6 When he had thus spoken, he spat on the ground, and made clay of the spittle, and he anointed the eyes of the blind man with the clay,
7 And said unto him, Go, wash in the pool of Siloam, (which is by interpretation, Sent.) He went his way therefore, and washed, and came seeing.
8 The neighbours therefore, and they which before had seen him that he was blind, said, Is not this he that sat and begged?
9 Some said, This is he: others said, He is like him: but he said, I am he.
10 Therefore said they unto him, How were thine eyes opened?
11 He answered and said, A man that is called Jesus made clay, and anointed mine eyes, and said unto me, Go to the pool of Siloam, and wash: and I went and washed, and I received sight.
12 Then said they unto him, Where is he? He said, I know not.

The Pharisees Investigate

13 They brought to the Pharisees him that aforetime was blind.
14 And it was the sabbath day when Jesus made the clay, and opened his eyes.
15 Then again the Pharisees also asked him how he had received his sight. He said unto them, He put clay upon mine eyes, and I washed, and do see.
16 Therefore said some of the Pharisees, This man is not of God, because he keepeth not the sabbath day. Others said, How can a man that is a sinner do such miracles? And there was a division among them.
17 They say unto the blind man again, What sayest thou of him, that he hath opened thine eyes? He said, He is a prophet.

18 But the Jews did not believe concerning him, that he had been blind, and received his sight, until they called the parents of him that had received his sight.
19 And they asked them, saying, Is this your son, who ye say was born blind? how then doth he now see?
20 His parents answered them and said, We know that this is our son, and that he was born blind:
21 But by what means he now seeth, we know not; or who hath opened his eyes, we know not: he is of age; ask him: he shall speak for himself.
22 These words spake his parents, because they feared the Jews: for the Jews had agreed already, that if any man did confess that he was Christ, he should be put out of the synagogue.
23 Therefore said his parents, He is of age; ask him.

24 Then again called they the man that was blind, and said unto him, Give God the praise: we know that this man is a sinner.
25 He answered and said, Whether he be a sinner or no, I know not: one thing I know, that, whereas I was blind, now I see.
26 Then said they to him again, What did he to thee? how opened he thine eyes?
27 He answered them, I have told you already, and ye did not hear: wherefore would ye hear it again? will ye also be his disciples?
28 Then they reviled him, and said, Thou art his disciple; but we are Moses' disciples.
29 We know that God spake unto Moses: as for this fellow, we know not from whence he is.
30 The man answered and said unto them, Why herein is a marvellous thing, that ye know not from whence he is, and yet he hath opened mine eyes.
31 Now we know that God heareth not sinners: but if any man be a worshipper of God, and doeth his will, him he heareth.
32 Since the world began was it not heard that any man opened the eyes of one that was born blind.
33 If this man were not of God, he could do nothing.
34 They answered and said unto him, Thou wast altogether born in sins, and dost thou teach us? And they cast him out.

Spiritual Sight and Blindness

35 Jesus heard that they had cast him out; and when he had found him, he said unto him, Dost thou believe on the Son of God?
36 He answered and said, Who is he, Lord, that I might believe on him?
37 And Jesus said unto him, Thou hast both seen him, and it is he that talketh with thee.
38 And he said, Lord, I believe. And he worshipped him.
39 And Jesus said, For judgment I am come into this world, that they which see not might see; and that they which see might be made blind.
40 And some of the Pharisees which were with him heard these words, and said unto him, Are we blind also?
41 Jesus said unto them, If ye were blind, ye should have no sin: but now ye say, We see; therefore your sin remaineth.

As you read above the Lord Jesus Christ healed the blind-born person by which manifesting Himself as a True expectedMessiah The Saviour of the Lord a Prophet and a True and Only Begotten Son of God.

The words of God directly fought the great proudness of Jewish Pharsiee wise people (thinking that know the Law better than the Lord himself). Their selfishness and great self-conceit make their soul which was in a terrible state to suffer because their produness was insulted by the truthful words and they felt wounded. They rejected the Lords words with a question by which Jewish (people) and nowadays often non-believers and even christian manifested wrath, selfishness and even mockery with contempt.

John 9:40 Are we blind also?

Answering the Pharisee's questions, The Lord has depicted there spiritual state, which was the main reason for their question. 

41 Jesus said unto them, If ye were blind, ye should have no sin: but now ye say, We see; therefore your sin remaineth.

The Pharisee's considered for spiritual seers,  in a highes level understandanding God, his laws covenant and respectively spiritual realm, so they did not need any further grown in God's knowledge, thus rejecting the true teaching which was taught by God himself.

False doctrines of this blind teachers are fruit of human proud and self-conceit. 
The proud understand himself as a independent, self-sufficient and not like a God dependent creation, the earthly life as something eternal and death and eternity for unexisting.

For this people God's plan was something not existing but God was understood as the Jewish law false teachers understanding of right and wrong in a way they have associated the eternal God with the scriptures, idolizing scriptures and inverting their meaning giving them a completely different meaning to fulfill their own passions.

This people who were to be the jewish intelligentia have recognized the human reason for a world ruler.
All the thoughts of the flesh crawl the land, the human understanding to this carnal men is completely sacrificed to the earth in which he wants to arrange his life to be all time pleasure of sin.
In this empty and unreachable goal was forced all the  fleshly and spiritual powers of both pharisees and sadukees. 

The Lord show them that the humbliness and remembrance of the dead should be the true lifely goal of man and it is  the humble-wisdom that gives an insight to eternity.

Achiving humble-Wisdom contradicts the wordly and strive for virtues and therefore it is not being considered worth for man and society material understanding of good and progress.
The one achiving spiritual knowledge understands himself as a tiny unimportant particle in a huge universe of things (generations, times, paste and future events of human history).

What the Lord Jesus Christ tried to point to this blind teachers is that only the Mind and heart of humble in contrasting to the proudness and high-minded people they were could accept God's Christian teaching and to all the time endeavor in achiving the christian virties.
The non-blind person sees and feels the great failure of (his mainly) and then all surrounding humanity fallen nature and because of this soul-pain and internal and desire for salvation and spiritual resurrection and restoration are ready to joyfully accept the Saviour Lord Jesus Christ.

Let us make from our heart a spiritual altar of God and there through our mind to sacrifice spiritual sacrifices of tenderness, repentance, confession, humble heartness (which God would not despise (Ps. 50:19) Amen 

Share this on

Linux: How to see / change supported network bandwidth of NIC interface and get various eth network statistics with ethtool

Monday, January 19th, 2015

If you're a novice Linux sysadmin and inherited some dedicated servers without any documentation and hence on of the first things you have to do to start a new server documentation is to check the supported TCP/IP network speed of servers Network (ethernet) Interfaces. On Linux this is very easy task to verify the speed of LAN card supported Local / Internet traffic install ethtool (if not already preseont on the servers) – assuming you're dealing with Debian / Ubuntu Linux servers.

1. Install ethtool on Deb and RPM based distros

dedi-server1:~# apt-cache show ethtool|grep -i desc -A 3
Description: display or change Ethernet device settings
 ethtool can be used to query and change settings such as speed, auto-
 negotiation and checksum offload on many network devices, especially
 Ethernet devices.

dedi-server1:~# apt-get install –yes ethtool

ethtool should be installed by default on CentOS / Fedora / RHEL and  syntax is same like on Debs. If you happen to miss ethtool on any (SuSE) / RedHat / RPM based distro install it with yum

[root@centos:~] # yum -y install ethtool

2. Get ethernet configurations

To check the current eth0 / eth1 / ethX network (Speed / Duplex) and other network related configuration configuration:

dedi-server5:~# ethtool eth0

Settings for eth0:
        Supported ports: [ TP ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
        Supports auto-negotiation: Yes
        Advertised link modes:  10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full

        Advertised pause frame use: No
        Advertised auto-negotiation: Yes
        Speed: 1000Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 1
        Transceiver: internal
        Auto-negotiation: on
        MDI-X: off
        Supports Wake-on: pumbag
        Wake-on: g
        Current message level: 0x00000001 (1)
        Link detected: yes

Having a NIC configured to act as Duplex is very important as Duplex communication enables LAN card to communicate both sides (Sent / Receive) packets simultaneously.


Probably most interesting parameters for most admins are the ones that are telling whether the NIC UpLink is 10megabyte / 100 megabyte or 1Gigabyte as well as supported Receive / Send ( Transfer ) speeds of LAN, a common useful ethtool admin use to just show current LAN ethernet interface speed:

server-admin1:~# ethtool eth0 |grep -i speed
        Speed: 1000Mb/s


To get info about NIC (kernel module / driver) used with ethtool:

dedi-server3:~# ethtool -i eth0 driver: e1000e
version: 1.2.20-k2
firmware-version: 1.8-0
bus-info: 0000:06:00.0

3. Make LAN Card blink to recognize eth is mapped to which Physical LAN

Besides that ethtool has many other useful use cases, for example if you have a server with 5 lan or more LAN cards, but you're not sure to which of all different EthX interfaces correspond, a very useful thing is to make eth0, eth1, eth2, eth3, etc. blink for 5 seconds in order to identify which static IP is binded physically to which NIC , here is how:

ethtool -p eth0 5

Then you can follow the procedure for any interface on the server and map them with a sticker 🙂

Ethtool is also useful for getting "deep" (thorough) statistics on Server LAN cards, this could be useful to identify sometimes hard to determine broadcast flood attacks:

4. Get network statistics with ethtool for interfaces

dedi-server5:~# ethtool -S eth0|grep -vw 0
NIC statistics:
     rx_packets: 6196644448
     tx_packets: 7197385158
     rx_bytes: 2038559235701
     tx_bytes: 8281206569250
     rx_broadcast: 357508947
     tx_broadcast: 172
     rx_multicast: 34731963
     tx_multicast: 20
     rx_errors: 115
     multicast: 34731963
     rx_length_errors: 115
     rx_no_buffer_count: 26391
     rx_missed_errors: 10059
     tx_timeout_count: 3
     tx_restart_queue: 2590
     rx_short_length_errors: 115
     tx_tcp_seg_good: 964136993
     rx_long_byte_count: 2038559235701
     rx_csum_offload_good: 5824813965
     rx_csum_offload_errors: 42186
     rx_smbus: 383640020

5. Turn on Auto Negotiation and change NIC set speed to 10 / 100 / 1000 Mb/s

Auto-negotiation is important as an ethernet procedure by which two communication devices (2 network cards) choose common transmission parameters such as speed, duplex mode, and flow control in order to achieve maximum transmission speed over the network. On 1000BASE-T basednetworks the standard is a mandatory. There is also backward compatability for older 10BASE-T Networks.

a) To raise up NIC to use 1000 Mb/s in case if the bandwidth was raised to 1Gb/s but NIC settings were not changed:

dedi-server1:~# ethtool -s eth0 speed 1000 duplex half autoneg off

b) In case if LAN speed has to be reduced for some weird reason to 10 / 100Mb/s


dedi-server1:~# ethtool -s eth0 speed 10 duplex half autoneg off

dedi-server1:~# ethtool -s eth0 speed 100 duplex half autoneg off

c) To enable disable NIC Autonegotiation:

dedi-server1:~# ethtool -s eth0 autoneg on

6. Change Speed / Duplex settings to load on boot

a) Set Network to Duplex on Fedora / CentOS etc.

Quickest way to do it is of course to use /etc/rc.local. If you want to do it following distribution logic on CentOS / RHEL Linux:

Add to /etc/sysconfig/network-scripts/ifcfg-eth0

vim /etc/sysconfig/network/-scripts/ifcfg-eth0

ETHTOOL_OPTS="speed 1000 duplex full autoneg off"

To load the new settings restart networking (be careful to have physical access to server if something goes wrong 🙂 )

service network restart

b) Change network speed / duplex setting on Debian / Ubuntu Linux

Add at the end of /etc/network/interfaces

vim /etc/network/interfaces

post-up ethtool -s eth0 speed 100 duplex full autoneg off

7. Tune NIC ring buffers

dedi-server1:~# ethtool -g eth0

Ring parameters for eth0:
Pre-set maximums:
RX:             4096
RX Mini:        0
RX Jumbo:       0
TX:             4096
Current hardware settings:
RX:             256
RX Mini:        0
RX Jumbo:       0
TX:             256

As you can see the default setting of RX (receive) buffer size is low 256 and on busy servers with high traffic loads, depending on the hardware NIC vendor this RX buffer size varies.
Through increasing the Rx/Tx ring buffer size , you can decrease the probability of discarding packets in the NIC during a scheduling delay.
A change in rx buffer ring requires NIC restart so (be careful not to loose connection to remote server), be sure to have iLO access to it.

Here is how to raise Rx ring buffer size 4 times from default value:

ethtool -G eth0 rx 4096 tx 4069

Share this on

Your Firefox profile cannot be loaded. It may be missing or inaccessible – Fix

Tuesday, May 27th, 2014


When I opened firefox I was offered that firefox cleans some data. Pressing on it took a long so I killed firefox process from Windows taskmanager (taskmgr).  . Next time Firefox was started I got the error (warning):

Your Firefox profile cannot be loaded. It may be missing or inaccessible"

Firefox version is 29.0.1.

Once the dialog, Firefox fails to further open. To fix Your Firefox profile cannot be loaded. It may be missing or inaccessible press windows-key+R to invoke <Open program prompt and type in:


In explorer Window that will pop=up rename the folder labelled "Firefox" to something like old-Firefox.
On next start of firefox, you will be offered to recrate "the missiong profile and it will force Firefox to re-create profile.

If you want to import some of your old data into the new profile afterwards: Recovering important data from an old profile check Recovering important data from an old profile Another approach is to to go to Firefox profile folder and delete profiles.ini, this will also make firefox recreate the file on its next start. Enjoy ! 🙂


Share this on

Mysql: How to disable single database without dropping or renaming it

Wednesday, January 22nd, 2014

mysql rename forbid disable database howto logo, how to disable single database without dropping it
A colleague of mine working on MySQL database asked me How it is possible to disable a MySQL database. He is in situation where the client has 2 databases and application and is not sure which of the two databases the application uses. Therefore the client asked one of the database is disabled and wait for few hours and see if something will break / stop working and in that way determine which of the two database is used by application.

My first guess was to backup both databases and drop one of them, then if it is the wrong one to restore from the SQL dump backup, however this wasn't acceptable solution. So second I though of RENAME of database to another one and then reverting the name, however as it is written in MySQL documentation RENAME database function was removed from MySQL (found to be dangerous) since version 5.1.23 onwards. Anyhow there is a quick hack to rename mysql database using a for loop shell script one below:

mysql -e "CREATE DATABASE \`new_database\`;"
for table in `mysql -B -N -e "SHOW TABLES;" old_database`
  mysql -e "RENAME TABLE \`old_database\`.\`$table\` to \`new_database\`.\`$table\`"
  mysql -e "DROP DATABASE \`old_database\`;"

Other possible solution was to change permissions of Application used username, however this was also complicated from mysql cli, hence I thought of installing and using PHPMyAdmin to make modify of db user permissions easier but on this server there wasn't Apache installed and MySQL is behind a firewall and only accessible via java tomcat host.

Finally after some pondering what can be done I came with solution to request to disable mysql database using chmod in /var/lib/mysql/data/, i.e.:

sql-server:~# chmod 0 /var/lib/mysql/databasename

Where databasename is the same as the database is named listable via mysql cli.

After doing it that way with no need to restart MySQL server database stopped to appear in show databases; and client confirmed that disabled database is no longer needed so we proceeded dropping it.

Hope this little article will help someone out there. Cheers :

Share this on