• VMware

    Learn about VMware virtualization for its products like vsphere ESX and ESXi, vCenter Server, VMware View, VMware P2V and many more

  • Linux

    Step by step configuration tutorials for many of the Linux services like DNS, DHCP, FTP, Samba4 etc including many tips and tricks in Red Hat Linux.

  • Database

    Learn installation and configuration of databases like Oracle, My SQL, Postgresql, etc including many other related tutorials in Linux.

  • Life always offers you a second chance ... Its called tomorrow !!!

    Tuesday, April 19, 2016

    ORA-28002: the password will expire within 6 days (certain string)

    I have been working in Sql developer for certain time, few days back found new notification/warning  windows is popping up with the error message - ORA-28002: the password will expire within 6 days (certain string) as below :



    Although there are many other ways you can get rid of this notification/warning like changing the user password. But I'll prefer to set this value as unlimited instead changing the Password again in few weeks later.

    Cause : Basically this is causing because Sql developer password expiration has been set to 180 days By default.

    How to see Expiration: To view the validity of the password you can use below query:

    select resource_name,limit from dba_profiles where profile='DEFAULT';

    Output:


    Now most of us will wonder can we change this date to unlimited, the answer is yes, we can by using below query:

    Alter Profile Default Limit Password_Life_Time Unlimited;

    Output: Profile DEFAULT Altered.

    To check if the Password has been reset successfully, execute below query and verify the result.

    select resource_name,limit from dba_profiles where profile='DEFAULT';


    Final Note :  You need to change the password again for new limit to take effect.

    Thanks for reading this post.




    Monday, April 18, 2016

    How to install MetaTrader 4 on Linux

    For years now, the MetaTrader 4 trading platform has been the top Forex platform around. It has perfect functionality, is lightweight, and has the best features.

    One of its lackings is that there is no MetaTrader 4 app for Linux computers. However, there are ways to install MetaTrader 4 on Linux that circumvent the problem.

    Here’s how you can install the MetaTrader 4 trading platform on Linux.

    Installing Wine on Ubuntu

    Ubuntu is the most popular Linux distribution kit, and as such MetaTrader 4 has provided instructions to install MT4 on it.


     can be used if you install Wine. Wine is free software that allows users of the Unix-based systems to run Windows applications.

    Before going further, you should be aware that the MT4 website warns that Wine is not a fully stable application. Some functions may not work properly or at all.

    If you decide to install Wine, follow these steps:

    Perform preliminary setup before the installation as follows:
         Open Ubuntu Software Center and execute “Software Sources” command in the “Edit” menu
         Click “Add” in the new window
         Specify the following data in the APT (Advanced Package Tool) line:
         ppa:ubuntu-wine/ppa
         Click “Add Source”

    This completes preliminary setup. Install Wine by doing the following:
         Go to http://www.winehq.org/
         Go to Downloads and choose the distribution kit for Ubuntu
         Click the link for the latest Wine version
         Click Agree in the prompt to open the link via Ubuntu Software Center
         Click “Install”

    Once Wine is installed you can start using MetaTrader 4.
         Download the MT4 installation file
         Select OK in the prompt that offers to open it with Wine
         Complete all installation steps
         Use MT4 by running its terminal.exe file

    Admiral Markets’ web app

    If you don’t want to go through the hassle of installing Wine, Admiral Markets now offers clients a custom browser-based version of the MetaTrader 4 trading platform. No download is necessary, and it can be accessed from any computer, operating system, and browser. The following capabilities are already available for traders to:
         trade Forex and other markets in the browser
         keep their account passwords secure
         use a familiar MT4-like interface
         enjoy one-click trading
         use basic technical analysis tools, such as trend lines and Fibonacci
         place any order types
         trade within 9 time-frames

    The MT4 based WebTrader for Linux is being constantly updated, with new capabilities added. The WebTrader provides higher flexibility to all traders, as well as lightening the burden of installing Wine on Linux.

    Only the best

    When you're trading Forex, you should use only the best tools. While MetaTrader 4 trading platform has long been considered the best, Linux users have only been able to access it with difficulty. You should now be able to access MetaTrader 4 no matter what operating system you are running.

    Thursday, March 31, 2016

    The best online games that run best on Linux


    When the week has been a bit monotonous or you are stuck in bed with the flu, make the most of a night out... by making it a night in. Europalace Casino is the perfect place to have all the fun of a live casino without any of the hassles. Running state of the art casino games on a Linux operating system will make all the difference between enjoying the games and really getting the most out of what the games offer in sounds,graphics and game play.  Whether you are an avid gamer or just a hobbyist, you can now scratch your way to mesmerising instant prizes with Europalace Casino as well as experience a range of riveting games using your Linux operating system. 


    Traditional Table Games

    From blackjack to poker, players are winning big playing both games at big online gaming platforms. Try your hand at a weekly game of Texas Hold 'Em or spend the weekend making the weekend work for you and let your card shark skills win you a little extra spending money. Whether you are a leisure player or a pro, you will find plenty of perfectly matched competition at Europalace.

    Whimsical Games

    Nothing is better for a case of the bad day blues than a whimsical game that carries you back to simpler times. From playful monsters to unforgettable characters, the vibrantly animated games are perfectly paired with Saturday morning cereal. Play alongside your partner to make your game days into date nights and bond over healthy competition... then, split the winnings over a steak, red wine and house salad.

    Themed Slot Games

    From Tomb Raider to Game of Thrones, geek out on themed slot games and reminiscent of a night in Vegas without the need to change out of your sweatpants. A great way to celebrate Game of Thrones finale night or a themed dinner while playing fun themed slot games are the perfect way to make the week just a little bit better.

    Spur of the Moment Scratch to Win Games

    Scratch games are some of the most popular games played at Europalace because you have the opportunity to win big. These games are the perfect end to a night of traditional gaming, giving you a surprise to look forward to at the end of your visit. Some players visit just for these types of games and just stop by once a week. For many of the players, this has become an event for the whole family to scratch one square at a time together. It is a great way to end family board game night with a bang and when you win... you can take the winnings out and use it for an ice cream soiree that you will all be able to enjoy together.

    From traditional, serious poker games to whimsical games that are all in fun, stop by Europalace and find out why UK gamers rave about the game play, the competition and the prizes. Whether you want to play away a sick day or just have a little fun on a Friday night, Europalace has something for every gamer and every gamer's style, making it the perfect place for anyone who needs a little fun in their life.


    Monday, October 26, 2015

    How to get the hardware model information in Linux

    The below commands are executed in SuSE Enterprise Linux so some of them might not work on other flavors of Linux.

    Run the below command and scroll a few lines where you should be able to see your machine's hardware model as shown below
    # dmesg | less
    (Scroll few lines and you should be able to find the hardware model)
    [    0.000000] DMI: HP ProLiant BL460c Gen9, BIOS I36 07/11/2014

    or you can execute the below command
    # dmesg | grep -i DMI
    [    0.000000] DMI 2.8 present.
    [    0.000000] DMI: HP ProLiant BL460c Gen9, BIOS I36 07/11/2014

    The below command will give you more information about your hardware including the model details
    # dmidecode -t system
    # dmidecode 2.12
    SMBIOS 2.8 present.

    Handle 0x0009, DMI type 1, 27 bytes
    System Information
            Manufacturer: HP
            Product Name: ProLiant BL460c Gen9
            Version: Not Specified
            Serial Number: SGH451XFL8
            UUID: 37373633-3230-5347-4834-353158464C38
            Wake-up Type: Power Switch
            SKU Number: 776320-B21
            Family: ProLiant

    Handle 0x008B, DMI type 32, 11 bytes
    System Boot Information
            Status: No errors detected

    You can alternatively also use 'hwinfo' command but the execution might take a while as it will collect all the information with regards to your hardware and then will dump the requested detail to STDOUT
    # hwinfo | egrep   "system.hardware.vendor|system.hardware.product"
      system.hardware.vendor = 'HP'
      system.hardware.product = 'ProLiant BL460c Gen9'


    Follow the below links for more tutorials

    How to find the path of any command in Linux
    How to configure a Clustered Samba share using ctdb in Red Hat Cluster
    How to delete an iscsi-target from openfiler and Linux
    How to perform a local ssh port forwarding in Linux
    How to use yum locally without internet connection using cache?
    What is umask and how to change the default value permanently?
    Understanding Partition Scheme MBR vs GPT
    How does a successful or failed login process works in Linux
    How to find all the process accessing a file in Linux
    How to exclude multiple directories from du command in Linux
    How to configure autofs in Linux and what are its advantages?
    How to resize software raid partition in Linux
    How to configure Software RAID 1 mirroring in Linux
    How to prevent a command from getting stored in history in Linux

    Sunday, October 25, 2015

    15 practical examples of rpm command usage in Linux

    I have written a blog explaining different fields of an rpm. To understand a rpm and all its fields follow the below link
    Understanding RPM package

    Here I have tried to summarize a list of rpm commands which can be helpful.

    1. Install a new package

    # rpm -ivh gcc-4.3-62.198.x86_64.rpm
    Preparing...                ########################################### [100%]
       1:gcc                    ########################################### [100%]

    2. Forcefully install a package

    # rpm -ivh gcc-4.3-62.198.x86_64.rpm
    Preparing...                ########################################### [100%]
            package gcc-4.3-62.198.x86_64 is already installed

    As you see since gcc rpm is already installed the installation does not completes so for such situations use should use --force switch as seen below
    # rpm -ivh gcc-4.3-62.198.x86_64.rpm --force
    Preparing...                ########################################### [100%]
       1:gcc                    ########################################### [100%]

    3. Upgrade a package

    # rpm -Uvh gcc-4.3-62.200.2.x86_64.rpm
    Preparing...                ########################################### [100%]
       1:gcc                    ########################################### [100%]

    4. Un-install a package

    To uninstall an rpm you need the exact name of the rpm which has to be installed. For eg if you have to uninstall gcc43-c++ then in case you run the below command to remove this
    # rpm -e gcc43-c
    error: package gcc43-c is not installed

    As you see you should provide complete name # rpm -e gcc-c++
    # echo $?
    0

    5. Install/Un-install a package without dependencies

    Make sure you are fully aware before you use this option since there is a probability that the package won't function properly if the dependencies are not installed. Although you can skip the same using --nodeps
    # rpm -ivh kiwi-instsource-5.05.25-616.1.x86_64.rpm
    warning: kiwi-instsource-5.05.25-616.1.x86_64.rpm: Header V3 DSA signature: NOKEY, key ID d3668a00
    error: Failed dependencies:
            build is needed by kiwi-instsource-5.05.25-616.1.x86_64

    # rpm -ivh kiwi-instsource-5.05.25-616.1.x86_64.rpm --nodeps
    warning: kiwi-instsource-5.05.25-616.1.x86_64.rpm: Header V3 DSA signature: NOKEY, key ID d3668a00
    Preparing...                ########################################### [100%]
       1:kiwi-instsource        ########################################### [100%]

    To remove a package you can use the same option

    # rpm -e kiwi-tools-5.05.25-616.1
    error: Failed dependencies:
            kiwi-tools >= 5.05.25 is needed by (installed) kiwi-5.05.25-616.1.x86_64

    # rpm -e kiwi-tools-5.05.25-616.1 --nodeps

    Alternatively you can also use --force along with --nodeps

    6. Display the Package's File List

    Adding -l to rpm -q tells RPM to display the list of files that are installed by the specified package or packages.
    # rpm -ql gcc
    /usr/bin/cc
    /usr/bin/gcc
    /usr/bin/gcov
    /usr/share/man/man1/cc.1.gz
    /usr/share/man/man1/gcc.1.gz
    /usr/share/man/man1/gcov.1.gz

    7. Display the Package's File List for non-installed rpm

    To check this make sure you have access to the rpm of which the content has to be checked
    # rpm -qlp squashfs-4.0-2.1.x86_64.rpm
    warning: squashfs-4.0-2.1.x86_64.rpm: Header V3 DSA signature: NOKEY, key ID 29b4acdd
    /usr/bin/mksquashfs
    /usr/bin/unsquashfs
    /usr/share/doc/packages/squashfs
    /usr/share/doc/packages/squashfs/CHANGES
    /usr/share/doc/packages/squashfs/PERFORMANCE.README
    /usr/share/doc/packages/squashfs/README
    /usr/share/doc/packages/squashfs/README-4.0

    8. Display Package's File List with Additional Information

    # rpm -qlv gcc
    lrwxrwxrwx 1 root root 7 Feb 21 2009 /usr/bin/cc -> gcc-4.3
    lrwxrwxrwx 1 root root 7 Feb 21 2009 /usr/bin/gcc -> gcc-4.3
    lrwxrwxrwx 1 root root 8 Feb 21 2009 /usr/bin/gcov -> gcov-4.3
    lrwxrwxrwx 1 root root 12 Feb 21 2009 /usr/share/man/man1/cc.1.gz -> gcc-4.3.1.gz
    lrwxrwxrwx 1 root root 12 Feb 21 2009 /usr/share/man/man1/gcc.1.gz -> gcc-4.3.1.gz
    lrwxrwxrwx 1 root root 13 Feb 21 2009 /usr/share/man/man1/gcov.1.gz -> gcov-4.3.1.gz

    9. Query the Package Owning <file>

    There might be a case when you know a file like /usr/bin/sudo but you are not sure which rpm is responsible for installing this file. Use -qf along with rpm command for such cases.

    NOTE: The below command is only useful if the file you are querying for is present in your machine
    # rpm -qf /usr/bin/sudo
    sudo-1.7.6p2-0.17.5

    10. Display a List of the Package's Documentation

    When -d is added to a query, we get a list of all files containing documentation for the named package or packages. This is a great way to get up to speed when you're having problems with unfamiliar software. As with -c and -l, you'll see either a simple list of filenames, or (if you've added -v) a more comprehensive list.
    # rpm -qd gawk
    /usr/share/doc/packages/gawk/AUTHORS
    /usr/share/doc/packages/gawk/COPYING
    /usr/share/doc/packages/gawk/FUTURES
    /usr/share/doc/packages/gawk/LIMITATIONS
    /usr/share/doc/packages/gawk/NEWS
    /usr/share/doc/packages/gawk/POSIX.STD
    /usr/share/doc/packages/gawk/PROBLEMS
    /usr/share/doc/packages/gawk/README
    /usr/share/info/gawk.info.gz
    /usr/share/info/gawkinet.info.gz
    /usr/share/man/man1/awk.1.gz
    /usr/share/man/man1/gawk.1.gz
    /usr/share/man/man1/igawk.1.gz
    /usr/share/man/man1/pgawk.1.gz

    11. Display the Package's List of Configuration Files

    When -c is added to an rpm -q command, RPM will display the configuration files that are part of the specified package or packages.
    # rpm -qc netcfg
    /etc/HOSTNAME
    /etc/aliases
    /etc/defaultdomain
    /etc/ethers
    /etc/exports
    /etc/ftpusers
    /etc/host.conf
    /etc/hosts
    /etc/hosts.allow
    /etc/hosts.deny
    /etc/hosts.equiv

    12. Query the Packages That Provide Capability

    RPM provides extensive support for dependencies between packages. The basic mechanism used is that a package may require what another package provides.
    # rpm -q --whatprovides gcc
    gcc-4.3-62.198

    13. Display Package Information

    # rpm -qi kernel-default-base
    Name        : kernel-default-base          Relocations: (not relocatable)
    Version     : 3.0.101                           Vendor: SUSE LINUX Products GmbH, Nuernberg, Germany
    Release     : 0.46.1                        Build Date: Wed Dec 17 09:19:54 2014
    Install Date: Fri Jun 12 05:31:11 2015         Build Host: sheep03
    Group       : System/Kernel                 Source RPM: kernel-default-3.0.101-0.46.1.nosrc.rpm
    Size        : 23896685                         License: GPL v2 only
    Signature   : RSA/8, Wed Dec 17 09:22:49 2014, Key ID e3a5c360307e3d54
    Packager    : http://bugs.opensuse.org
    URL         : http://www.kernel.org/
    Summary     : The Standard Kernel - base modules
    Description :
    The standard kernel for both uniprocessor and multiprocessor systems.

    This package contains only the base modules, required in all installs.

    Source Timestamp: 2014-12-17 12:04:10 +0100
    GIT Revision: 8356111faa769f649b6d7c8b5bcbb34fb17120aa
    GIT Branch: SLE11-SP3-CVE-2014-9322
    Distribution: SUSE Linux Enterprise 11

    14. Display Capabilities Provided by the Package

    By adding --provides to a query command, we can see the capabilities provided by one or more packages. If the package doesn't provide any capabilities, the --provides option produces no output:

    # rpm -q gcc --provides
    c_compiler
    gcc = 4.3-62.198

    15. Query All Installed Packages

    Using the -a option, you can query every package installed on your system. For example:
    # rpm -qa | grep kernel
    kernel-default-devel-3.0.76-0.11.1
    kernel-firmware-20110923-0.42.49
    kernel-source-3.0.76-0.11.1
    linux-kernel-headers-2.6.32-1.13.5
    kernel-default-3.0.101-0.46.1
    kernel-default-base-3.0.101-0.46.1
    kernel-default-extra-3.0.101-0.46.1

    Follow the below links for more tutorials

    How to find the path of any command in Linux
    How to configure a Clustered Samba share using ctdb in Red Hat Cluster
    How to delete an iscsi-target from openfiler and Linux
    How to perform a local ssh port forwarding in Linux
    How to use yum locally without internet connection using cache?
    What is umask and how to change the default value permanently?
    Understanding Partition Scheme MBR vs GPT
    How does a successful or failed login process works in Linux
    How to find all the process accessing a file in Linux
    How to exclude multiple directories from du command in Linux
    How to configure autofs in Linux and what are its advantages?
    How to resize software raid partition in Linux
    How to configure Software RAID 1 mirroring in Linux
    How to prevent a command from getting stored in history in Linux