Thursday, September 24, 2015

Basic Interview Questions for Linux and VMWARE

Hi Friends,


Listings down some of the basic interview questions for linux and vmware:-

1. The output of top and free -m command are showing discrepancies, what could be the reasons?
2. The kernel parameters which can affect the performance of network, name them and with reasons?
3. the load avg. is 40 % , is it ideal for a server?
4. What is VMOTION, DRS, SDRS?
5.  What are the best hardening techniques you will use before handing over a server for the use of Web application demanding high I/O?
6. What is nice and how you can use it?
7. What is ballooning?
8. what are the differences between Distributive and standard switch?


Thanks
Amit Chopra

Yes, A blind can see

Friends,

With the use of this gadget a blind can listen the name and hint of the thing in front of him. A database of 100 to 1000 objects, which will be referred by the scanner and live camera placed on the eyes of a blind ( A spec) and after analyses the application will speak in the ears of the person about the object in front of him can make this possible.

so what do you think. shortly a picture of this will be shown and then a working model.

Thanks for reading
Amit Chopra

Monday, September 21, 2015

A DREAM FOR A BLIND TO SEE :: A GADGET

Dear Friends,

We are very much amazed by the launch of Digital phones and their new applications, they leave us in a state of illusion happening in front of us because we like the changes that we can see and feel. Is the life belong to only those who have eyes and can see the world using them. My question and thought may feel not new to you, but the idea i have with me carries a vision and energy to push our electronic or digital world more further.
                               We all know life is precious and we love it more than any thing, we take dreams, some of us live that dream as well with their efforts or by God grace. but what about those who see dreams and if they make it happen also, they still can't  see it. Imagine a blind who can touch and say that in front of him is a bus, he can describe the shape but in reality he cannot see it, he cannot explain the colors,etc. the life of a blind is very difficult here in developing countries, i really do not know how developed countries are dealing with their problems. it is not only about providing a seat in Train, in a bus, on airplane, a keeping a reservation for a job for blind or challenged person. these are small steps for them to improve their living standards.
My thought is on a new gadget, which can allow them to see and hear what is in front of it. I am an Engineer so thinking is from that background only. this gadget will help them to hear what is in front of them, called LIVE CAMERA SCANNER and SPEAKER. The blind is not a curse to any society in any way, instead they have more qualities than a human who can see. they see life from a different view. now how this LIVE CAMERA SCANNER RECORDER and SPEAKER works.
This gadget is a spec that is connected to a digital diary carrying database and application. it will read any thing in front of the glass and get back to database to query that what it is and once the database verifies that the image is known and matches with a database of alike shape and features then the same name will be said in the Blind's ear and Blind can recognize the thing and move forward with his superb intelligence.
lets take an example:- A person who is completely blind and cannot see anything, but can hear any small voice clear will wear this spec or glasses. Assume he is crossing a road or want to board a bus, then this glass will work as a live camera and will capture the very recent image which is in front of him and go to database to inquire about the same, once database say that this image matches the features of a road or bus then will speak in the ear of blind person. and that signal will help blind to cross the road by himself or climb the bus when it stops in front of him. He will be able to help himself. Yes the database and language required for this gadget should be able to work on live scenarios and ability of size of database should be enough capturing and carrying photographs. If he is able to hear the voice and he knows that in front of a bus is coming then their is no chance he will ever carry a stick or act like a dependent.
Another example:- if he stays in a home, the basic requirements are to know the stairs, to know which floor is it, to know where is the door, to know where is the washroom, and to recognize the name of the person who is standing in front of him if the other person doesn't speak a word.  in this way he can make himself more secure if the other person is his friend or enemy. everything will be spoken in his/her ears with in very shot span of time and he will be able to recognize with the help of this gadget.
this idea if already developed then i may the person who doesn't know it, and if developed also then please make this available in developing countries as they demand more because a Developed country makes more arrangement for physically challenged than a developing country. I can't see a blind man touching, imagining and then feeling who is in front of him.
                                            About Gadget, the gadget will surely not cost to high as it will only carry this application and database, speaking feature and a calling one.
Kindly share what you think of this idea and what are the chances of its social usage. there are lot to say about this idea and to do. need your positive comments to boost up this gadget development. I Do hope that one day blind will be able to see like us. Blind will see for sure. they will have eyes.


Thanks for reading
Amit Chopra

Sunday, September 20, 2015

Katello Installation on Cent OS 7.1

Katello is a free tool available on REDHAT and CENT OS to implement and deploy (using Kickstart method)/ 
It is similar like openstack provided by Redhat. Important links shared by katello are below we can follow up and install and configure. 

Detail :- Katello brings the full power of content management alongside the provisioning and configuration capabilities of Foreman. katello provided below features:- 
Local Yum and Puppet Repositories.
Snapshot Content and Configuration for Reproducible Builds.
Issue Package and Errata Updates
and much more features...


http://www.katello.org/
http://www.katello.org/docs/installation/index.html


Deployment steps. please provide your feedback and share errors if you find any while performing the implementation. 

[root@katello-02 ~]# history
    1  date
    2  chkconfig firewalld off
    3  vi /etc/selinux/config
    4  setenforce 0
    5  hostnamectl set-hostname lhr1-katello-02
    6  vi /etc/hosts
    7  vi /etc/sysconfig/network
    8  init 6
    9  /etc/init.d/network restart
   10  ifconfig
   11  vi /etc/sysconfig/network-scripts/ifcfg-ens192
   12  /etc/init.d/network restart
   13  ping 10.80.20.1
   14  hostname
   15  hostname --fqdn
   16  ping google.com
   17  yum -y localinstall http://fedorapeople.org/groups/katello/releases/yum/nightly/katello/RHEL/7Server/x86_64/katello-repos-latest.rpm
   18  yum -y localinstall http://yum.theforeman.org/nightly/el7/x86_64/foreman-release.rpm
   19  yum -y localinstall http://yum.puppetlabs.com/puppetlabs-release-el-7.noarch.rpm
   20  yum -y localinstall http://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
   21  yum -y install foreman-release-scl
   22  yum -y install katello
   23  yum install ruby rubygems ruby-devel gcc
   24  rpm -ivh vagrant_1.7.4_x86_64.rpm
   25  git clone https://github.com/Katello/katello-deploy.git
   26  cd katello-deploy/
   27  ls
   28  ls -ltr
   29  yum install @virtualization libvirt-devel
   30  vagrant plugin install vagrant-libvirt
   31  export VAGRANT_DEFAULT_PROVIDER=libvirt
   32  katello-installer --capsule-tftp=true
   33  katello-installer --capsule-dns=true --capsule-dns-interface="ens192" --capsule-dns-zone="prd.rmsonecloud.net" --capsule-dns-forwarders="10.80.20.214" --capsule-dns-reverse="20.80.10.in-addr.arpa"
   34  katello-installer --capsule-dhcp-range="10.80.112.11 10.80.112.199" --capsule-dhcp-gateway="10.80.112.1" --capsule-dhcp-nameservers="10.80.20.81"
   35  exit
   36  cd katello-deploy/
   37  vagrant up
   38  katello-installer
   39  hostname
   40  pwd
   41  ls
   42  ls -ltr
   43  cd katello-deploy/
   44  ls
   45  ls -ltr
   46  cd test/
   47  lds
   48  ls
   49  ls -ltr
   50  date
   51  cd /var/lo
   52  cd /var/log/
   53  ls
   54  ls -ltr
   55  date
   56  more messages
   57
   58  tail -f messages
   59  ls -ltr
   60  cd /var/lib/tftpboot/
   61  ls -ltr
   62  cd pxelinux.cfg
   63  ls -ltr
   64  pwd
   65  ifconfig
   66  yum install subscription-manager
   67  yum clean all
   68  yum install subscription-manager
   69  yum install python-rhsm-1.8.0-2.pulp.el7.x86_64
   70  yum update python-rhsm
   71  yum upgrade python-rhsm
   72  rpm -Uvh python-rhsm
   73  rpm -qa |grep -i python-rhsm
   74  rpm -Uvh
   75  pwd
   76  ls
   77  ls -ltr
   78  rpm -Uvh python-rhsm-1.13.10-1.el7.x86_64.rpm
   79  yum install subscription-manager
   80  subscription-manager
   81  subscription-manager version
   82  rpm -Uvh http://$KATELLO_HOSTNAME/pub/katello-ca-consumer-latest.noarch.rpm
   83  rpm -Uvh http://$10.80.20.81/pub/katello-ca-consumer-latest.noarch.rpm
   84  rpm -Uvh http://10.80.20.81/pub/katello-ca-consumer-latest.noarch.rpm
   85  subscription-manager register --org=Default_Organization --environment=Library
   86  subscription-manager register --org=Default_Organization --environment=Devel/MyView
   87  pwd
   88  ls
   89  ls -ltr
   90  cd katello-deploy/
   91  ls
   92  ls -ltr
   93  cd test/
   94  ls
   95  cd ../config/
   96  ls
   97  ls -ltr
   98  cd ../lib/
   99  ls
  100  ls -ltr
  101  cd katello_deploy/
  102  ls
  103  ls -ltr
  104  cd processors/
  105  ls
  106  ls -ltr
  107  pwd
  108  cd ..
  109  ls
  110  ls-ltr
  111  cd ..
  112  pwd
  113  cd /var/log
  114  ls
  115  ls -ltr
  116  date
  117  tail -f messages
  118   subscription-manager list --available
  119   subscription-manager list
  120  subscription-manager list --available
  121  history |grep katello
  122  capsule-certs-generate --capsule-fqdn "$CAPSULE" --certs-tar "~/$CAPSULE-certs.tar"
  123  cd ~/katello-deploy/
  124  capsule-certs-generate --capsule-fqdn "$CAPSULE" --certs-tar "~/$CAPSULE-certs.tar"
  125  katello-installer --capsule-dhcp-range="10.80.112.11 10.80.112.199" --capsule-dhcp-gateway="10.80.112.1" --capsule-dhcp-nameservers="10.80.20.81"
  126  wget http://mirror.aarnet.edu.au/pub/centos/6.5/
  127  ls
  128  ls -ltr
  129  cat index.html
  130  l
  131  ls -ltr
  132  rm index.html
  133  hostname
  134  df -h
  135  pwd
  136  cat /etc/dhcp/dhcpd.conf
  137  cat /etc/dhcp/dhclient.d/chrony.sh
  138  ps -ef |grep -i dhcp
  139  yum install dhcp
  140  pwd
  141  yum clean all
  142  yum list all
  143  pwd
  144  ls
  145  cd /etc/yum.repos.d/
  146  ls
  147  ls -ltr
  148  pwd
  149  date
  150  vi /etc/dhcp/dhcpd.conf
  151  systemctl status dhcp
  152  systemctl status dhcpd
  153  systemctl start dhcpd
  154  systemctl status dhcpd.service
  155  /usr/sbin/dhcpd -f -cf /etc/dhcp/dhcpd.conf -user dhcpd -group dhcpd --no-pid
  156  systemctl status dhcpd.service
  157  cat /etc/dhcp/dhcpd.hosts
  158  touch /etc/dhcp/dhcpd.hosts
  159  cat /etc/dhcp/dhcpd.hosts
  160  vi /etc/dhcp/dhcpd.hosts
  161  ls -ltr /etc/dhcp/dhcpd.hosts
  162  systemctl start dhcpd
  163  systemctl status dhcpd.service
  164  ps -ef |grep dhcp
  165  history
[root@katello-02 ~]#


some steps are performed to perform some troubleshooting, you can avoid them.

Thanks
Amit Chopra