Centos 7 - Download - install inside virtual box - run centos from virtual box - user: root //this is the default user name - sudo dhclient You can also make the OS load up the dhclient command when you login, by running the following command by Dylan Fernandez sed -i 's/ONBOOT=no/ONBOOT=yes/' /etc/sysconfig/network-scripts/ifcfg-enp0s3 Note: The sed command will search the text ONBOOT=no and replace it to ONBOOT=yes inside the file ifcfg-enp0s3 located at /etc/sysconfig/network-scripts/ then reboot your Centos OS and reload it. From this time on, it the dhclient will load at boot up time. - sudo yum install net-tools - sudo yum update && upgrade - sudo yum install java - java -version - sudo yum install javac-devel - javac -version If the previous command does not work try the following - sudo yum install java-devel - javac -version - sudo yum install wget //installing wget - wget -U firefox target // running wget. Found by Menendez Mitchell - Install locate command //command to locate any file with ???? on their name - yum install mlocate - updatedb - to execute run: locate target NOT mlocate target ex: locate javac Set full size screen - yum install gcc epel-release.noarch kernel-headers kernel-devel - On the view choice select: Scale Factor (I selected 200%) -------------------------------------------------------- Full Size Screen and resolutions by Rafael Serrano: Steps for CentOS 7 Virtual Box (Windows 10 host) Before running your VirtualBox program, download the Virtual Box guest Additions needed for your kernel from this link: http://download.virtualbox.org/virtualbox/ Make sure that you choose the same version as the one for your virtual box (you can find it by pressing help and about virtual box ). Press on the version and download, in my case, it is VBoxGuestAdditions_5.2.6.iso file Add VBoxGuestAdditions_5.2.6.iso to a disk on your Centos - Highlight your OS vm, - Choose Setting - Select Storage - Add a new disk, and look for your iso file. - In Controller:IDE there are two options: - Adds optical disk and Adds hard disk. - Choose optical disk - then "choose disk" and add the VBoxGuestAdditions_5.2.6.iso you previously downloaded. - Run your VM and click on devices - Install guest additions (you may have and error message, do not worry that means that the vmadditions cd is already associated with your vm, but it is not dhclientinstalled) Open your CentOS machine and run the following commands: 1. sudo -i or su - 2. yum update kernel* 3. reboot 4. mkdir /media/VirtualBoxGuestAdditions 5. mount -r /dev/cdrom /media/VirtualBoxGuestAdditions 6. rpm -Uvh https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm 7. yum install gcc kernel-devel kernel-headers dkms make bzip2 perl 8. KERN_DIR=/usr/src/kernels/`uname -r`/build 9. export KERN_DIR 10. cd /media/VirtualBoxGuestAdditions 11. ./VBoxLinuxAdditions.run 12. Reboot Close your machine, open Virtual Box, with you machine selected go to file (top right corner), preferences, at Maximum Guest Screen Size select Hint and chood your screen size desired and set a hint display (depending in your screen, put the maximum resolution). such as: 640 x 480 800 x 600 1024 x 768 1152 x 864 1280 x 720 1280 x 800 1366 x 768 1440 x 900 1600 x 900 1680 x 1050 1920 x 1080 1920 x 1200 Run your machine again, and do the following commands: 1. sudo su 2. vi /etc/default/grub ***Press I to format the text 3. Add vga=792 inside the "-quotes for GRUB_CMDLINE_LINUX, f.ex. GRUB_CMDLINE_LINUX="crashkernel=auto rhgb quiet vga= [NUMBER HERE]" [NUMBER HERE] == The value that is equal to your vga resolution, you can find some values here: https://www.pendrivelinux.com/vga-boot-modes-to-set-screen-resolution/ For example: for a 1024x768x24 the value will be 792. Depth 800x600 1024x768 1152x864 1280x1024 1600x1200 8 bit vga=771 vga=773 vga=353 vga=775 vga=796 16 bit vga=788 vga=791 vga=355 vga=794 vga=798 24 bit vga=789 vga=792 vga=795 vga=799 4. Press esc and type :wq and hit enter 5. grub2-mkconfig -o /boot/grub2/grub.cfg 6.reboot When rebooting your machine you have three options from where you can boot: Use the one that is CentOS Linux (3.10.0-862.el7.x86_64) 7 (Core) In my computer is the second one. Boot and the resolution should be fine. NOTE: Is will not be 100% properly adapted to your screen and you will need to use the side navigation bar. -------------------------------------------------------- SET Email for CENTOS7: The goal here is to use your gmail email account as an SMTP email server to send your emails out dhclient /if it is not automatically loading as shown in the dhclient section above --First go to the gmail account that you want to add to CentOS 7: yum 1.Go to the Less secure apps section of your Google Account. https://support.google.com/accounts/answer/6010255?hl=en 2.Turn on Allow less secure apps. If you don't see this setting, your administrator might have turned off less secure app account access. Open CentOS 7: --In the terminal run the following commands: dhclient //make sure that you are connected to the net, you can run ping google.com to be sure. yum -y install postfix cyrus-sasl-plain mailx //Install Postfix with SASL authentication systemctl restart postfix //restart the service systemctl enable postfix //start and boot the service vi /etc/postfix/main.cf //open the main.cf file that comes with postfix and add the following lines at the end of the file relayhost = [smtp.gmail.com]:587 smtp_use_tls = yes smtp_sasl_auth_enable = yes smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd smtp_tls_CAfile = /etc/ssl/certs/ca-bundle.crt smtp_sasl_security_options = noanonymous smtp_sasl_tls_security_options = noanonymous //save and close the file vi /etc/postfix/sasl_passwd //create a new file that will hold your username and password. Make sure that no one can see your screen at this time. Add the following line : [smtp.gmail.com]:587 username:password Insert a valid gmail account and password Since we are using the gmail SMTP server, if you are using your gmail acount you can use: examples: joe007:secrect Using other emails: examples: joe007@fiu.edu:secrect postmap /etc/postfix/sasl_passwd //generate a postfix lookup table chown root:postfix /etc/postfix/sasl_passwd* chmod 640 /etc/postfix/sasl_passwd* //restrict the access to the sasl_passwd file Only root users can acess it now systemctl reload postfix //reload the postfix config. echo "This is a test." | mail -s "test message" user@example.net //send a test email to a valid gmail account It can be your account. --Check if you have recived an email in your account. If not make sure that your account and password are correct. --You can also run: tail -f /var/log/maillog //to review the emails sent. debug_peer_list=smtp.gmail.com debug_peer_level=3 //to check where the error is located systemctl reload postfix //reload the system. --Email with a file attached: echo "This is a test message" | mail -s Test -a example.txt user@example.com //echo "This is a test message" is the body of the email //-s Test is the subject // -a example.txt the file that you want to attach. Make sure that you send the mail from the directory where the file is located in orde to access that file. //user@example.com receiver email account -------------------------------------------------------- - Sharing VM's Clipboards (Copy and Paste between VM's) - On Virtual Box select settings - Select general - Select advanced - Select on Shared Clipboard bidirectional - Select Drag/Drop bidirectional - reboot //reboots your vm - poweroff //exits and turns off your vm