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

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

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