Changes

= Basic = OBJECTIVE & PREPARATION==In OPS235, you learned how to configure a virtual private network configuration =for your '''vm1''', '''vm2''' and '''vm3''' virtual machines. You were required to configure a static network connection for your VMs. In OPS335, you will also be setting up a static network connection for all of your VMs (which all VMs will be text-based). All of the services that we install and configure for this course '''require a working network connection'''; therefore, it is very important that you know how to configure a network connection for your VMs, whether via command line for trouble-shooting purposes, or to create a persistent (permanent) network connection that uses static IP address (as opposed to DHCP).

Remember how you set up This lab is a <u>review</u> of the network interfaces in your virtual machines in OPS235? You're expected to know that inside out by nowmaterial from labs 6 ( [http://zenit.senecac.on.ca/wiki/index.php/OPS235_Lab_6_-_CentOS7#Part_4:_Configuring_VM_Network_Setup_via_Command_Line_.28centos3.29 CLI Network Configuration] ), but will also additional topics.

This lab is a crash course of the material from labs 6 and 7 from *[httphttps://zenitwww.senecactty1.onnet/blog/2010/ifconfig-ip-comparison_en.cahtml ip vs ifconfig]*[https:/wiki/indexwww.phpdigitalocean.com/OPS235_Weekly_Schedule_community/tutorials/how-_CentOS7 OPS235to-use-rsync-to-sync-local-and-remote-directories-on-a-vps rsync Howto]*[https://help.ubuntu.com/community/CronHowto Cron HowTo]

== Check current settings INVESTIGATION 1: BASIC NETWORK CONFIGURATION (REVISITED) ==

In OPS235 Remember how you've used set up the ifconfig network interfaces in your virtual machines in OPS235?You are expected to be familiar with how to configure and route commands. In test out a VM's network connectivity at this course we'll use the ip command instead (you're welcome to use the old commands but you're expected to know the new ones too)point.

You'll need a file that describes ''Perform the settings for a network interface. The association between a specific network interface and the configuration file is made using (from least to most important)following steps:* The name of the file ('''ifcfg-'''interfacename)* The "NAME" setting inside the file* The "DEVICE" setting inside the file* The "HWADDR" setting inside the file

To set the hostname you use # View the table below comparing ''older''vs 'hostnamectl'newer'' commandmethods of obtaining network setting information for a Linux machine.

Except for the host all the machines in this course will have static network configuration. That means you need to be able to perform said configuration ::'''Comparison of Older and debug problems quickly. If the following steps arenNewer Methods of Obtaining Network Settings'''t 100% clear - make sure to practice them.

# Edit each of your VMs to use a static IP address. vm1 should use the first available address in the subnet, vm2 the second and vm3 the third.<table border="1" cellspacing="0" cellpadding="5" style="margin-left:51px;"># Don<tr><td>'''Purpose'''</td><td>'''Older Method'''<br>'t forget to set the default gateway and DNS server. You can use your host's IP address as a DNS server (libvirt will proxy the requests to the real DNS servercommand).# Make note of the files used and entries required.# Restart each VM and run the following ''</td><td>'''Newer Method'''<br>''(command to ensure they still have the network configuration you set.)''</td></tr># Test connectivity by pinging each of your VMs.# Try to ssh from the guest to the host machine, then from the host to the guest. # Try to ping matrix <tr> <td>Obtain IP ADDRESS and google from your host machine.# Try to ping matrix and google from each of your VM's to ensure you can reach the outside world.Subnet Mask</td><th>ifconfig</th><th>ip address</th></tr>

If everything works <tr> <td>Obtain Default Gateway</td><th>route - great. If not, move on to the next section.n</th><th>ip route</th></tr>

# '''Is it plugged in?''' On a physical network you would check whether the cable is plugged in and the link light is on on your network card. In a virtual network environment you don't have that - you'll need to check the NIC settings in the virtual machine details. In there it will tell you which virtual network your virtual network card is connected to.# '''Is it turned on?''' This is a problem more common with virtual networks than physical networks. Check in your VirtManager<tr> <td>See MAC cache</td><th>arp -n</th>ConnectionDetails-<th>VirtualNetworks that your network is active.# '''Do you have an IP address?''' Run '''ip address''' to check.# '''Can you ping the host by IP?''' (by its internal IP address). If not - check all of the above, check if you have an IP address conflict, check that your subnet mask is correct.# '''Can you ping 8.8.8.8?''' If all of the above work - check that your default gateway is set correctly with '''ip route''' and that you can ping the default gateway.# '''Can you resolve google.ca?''' Run '''host google.ca'''. If it doesn't come back with an IP address, and all of the above worked - check that your DNS server is configured correctly and that you can ping it.neighbour</th></tr>

The <ol><li value="2">Run the '''ifconfig''' command on your '''host''' machine. Check and record the IPADDR for your default (dhcp) network interface card (possibly eno1) and often the onlyvirtual bridge.</li><li>Issue the '''ip''' command on your '''host''' machine to determine the IPADDR and GATEWAY information (refer to above chart) way to administer a linux server is via SSH. Even in How are the result similar or different than the ifconfig command?</li><li>Issue the ifconfig command on your VMs. what happened?</li><li>Use the '''ip''' command for your case where you have a direct console VMs to all your VM screens you may find it helpful list the IPADDR and GATEWAY information.</li><li>Refer to connect the man pages or refer to your virtual machines using SSH (if nothing else following article [http://www.tecmint.com/ip-command- you can resize examples/ 10 Useful ip Commands] to see how to issue the terminal window)above commands to create a <u>temporary</u> connection to your existing network.</ol>

* '''systemctl start/stop'''In your OPS235 course, you used a series of commands (ifconfig, route, and nameserver) to setup a temporary network connection. You can use the ip command (a another command) in a similar way to create a temporary network connection. The problem with this network connection method is that those changes will be lost if you restart your Linux machine, although you may want to do that to create a temporary network connection for troubleshooting purposes. * '''systemctl enable/disable'''In order to have your network settings become permanent, you need to edit and save the settings changes in a file.* For the IP address, subnet mask, default gateway, and DNS server you edit that file is contained in a directory called '''systemctl statusnetwork-scripts'''.

Using # Change to the magic ''network-scripts'' directory (see your ''OPS335''/''OPS235''/''ULI101'' notes).# The name of public key cryptography the file that contains your persistent network settings has the following name format:<br>'''ifcfg-''interfacename'''''# Which file-name in your network-scripts directory do you can SSH think contains your current network settings?# View the contents of the file to a linux machine without using a passwordsee if it contains the IP address, subnet mask, and default gateway. This topic # What is crucial - not only for the MAC address if your current machine?# Does this course but in file contain the industryhostname of your machine? If not, SSH keys are used everywhere that linux servers are used.what command can allow you to change your machine's hostname?

[[Image:ssh_connection_explainedExcept for your host machine, all the Virtual Machines in this course will have '''static network configuration''' (as opposed to Automatic or DHCP). Sometimes, you will be required to debug networking problems quickly by changing the network configuration of your VMs.png|800px]]

<ol><li value="7">Edit the '''ifcfg-''interfacename''''' (most likely ifcfg-eth0) file for each of your VMs to use a static IP address (refer to previous OPS235 lab on networking: [ [https://wiki.cdot.senecacollege.ca/wiki/OPS235_Lab_6#Part_3:_Configuring_VM_Network_Setup_via_Command_Line_.28centos3_and_centos2.29 Network Config - CLI] ].<br> You should be configuring the BOOTPROTO ('''static''' instead of dhcp), IPADDR, PREFIX (or NETMASK), GATEWAY, HWADDR, and DNS1 for this file. Note the following information for this setup:<ul><li>Set your IPADDR for each VM with the following rules:<ol type== Public"a"><li>Your IPADDR's third octet will use the last 2 digits in your student number.</li><li> Make certain that the 4th octet for your VMs does not start with '''1''' since that is reserved by your host machine.<br>Use the recommended fourth octets: '''2 for vm1''', '''3 for vm2''', and '''4 for vm3'''.</li></ol></li><li>Don't forget to set the default gateway and DNS server for your VMs. You can use your host's IP address as a gateway and DNS server<br>(''libvirt'' will proxy the requests to the real DNS server).</li><li> You can refer to your previous lab to obtain information for setup of these options: [ [https://wiki.cdot.senecacollege.ca/wiki/OPS335_Installation_Lab#Configuring_a_VM_host Configuring a VM Host] ]<br><br></li></ul><li>Make note of the files used and entries required and note them in your lab log-book.</li><li>Save your editing session, and then restart each VM and run the following command to ensure they still have the network configuration you set:<ul><li>'''ping''' (what is the purpose of this command?). Try to ping google from your host machine.<br>Try to ping google from each of your VM's to ensure you can reach the outside world.</li><li>'''ssh''' (into another server, like Matrix) </li></ul></li><li>After setting the network configuration for EACH VM, then either the the ifdown and ifup commands or reboot each VM, to verify that you can connect to the Internet with the new static IP network configuration. If you cannot connect to the Internet, then check the network configuration file and make corrections until you have a workable network connection for each VM from boot-up.</Private key pair ===ol>

You generate a new keypair If you are uncertain how to perform those above-listed operations by member, take time to practice them.If everything works and you are comfortable with this command (press enter for all these operations then you may proceed to the questions):next section.

<source lang="bash">ssh-keygen -t rsa</source>== Linux Network Connection Configuration Troubleshooting ===

You'll end up with ~/.ssh/id_rsa and ~/.ss/id_rsa.pub - now If the network works in your host, but not in your Virtual Machine, you have a key pair you can use for authentication.should perform the following routine steps to troubleshoot the network connection:

=== Public key # '''IS THE NETWORK ON VM PLUGGED IN?''' On a physical network you would check whether the cable is plugged in and the link light is on on your network card. In a virtual network environment, you don't have a physical network adapter. Instead, you will need to check the NIC settings in the <u>'''virtual'''</u> machine details to view and confirm the appropriate network connection.# '''IS THE NETWORK ENABLED?''' This is a problem more common with virtual networks than physical networks. Check in:<br> '''VirtManager'''-> '''ConnectionDetails'''-> '''VirtualNetworks''' that your network is active.# '''DO YOU HAVE AN IP ADDRESS?''' Run '''ip address''' to check.# '''CAN YOU PING THE HOST BY IP?''' (by its internal IP address). If not - check all of the above, check if you have an IP address conflict, and check that your subnet mask is correct.# '''CAN YOU PING 8.8.8.8?''' If all of the above work - check that your default gateway is set correctly with '''ip route''' and that you can ping the default gateway.# '''CAN YOU RESOLVE google.ca?''' Run '''host google.ca'''. If the output doesn't provide an IP address, check that your DNS server ===is configured correctly and that you can ping that address.

If you have the private key - you can prove to someone who has your public key that you're really the owner There are a number of other problems that public key. That's how ssh key authentication works, so the server needs to have you user's public key. You can copy it over manually and append the contents of could prevent your ~/.ssh/id_rsa.pub network connection from functioning but the client to ~/above are the most common problems.ssh/authorized_keys on the server, or you can issue this command on the client to do all that for you:

After that you can login without You will now download, set execute permissions and run a passwordBash shell script to try to "break" the network connection for your vm1. But remember - keys are per userThis will provide troubleshooting practice to check your network configuration file, not per machine. So this will only work with one user on the client look and correct errors and one user on the server (the two users involved in running the command above)restart your network interface connection.

Rsync #Move to your '''vm1''' machine and make certain that you are logged in as '''root'''.#Make certain that the '''wget''' command is a very versatile backup toolavailable on your VM. If not, install the wget application. Make certain to do for ALL of your VMs. As #Use the name suggests it's used for synchronising files typically across a ''wget''' command (with option "--no-check-certificate" ) to download and run the following shell script:<br>http://scs.senecacollege.ca/~murray.saul/ops335/break-network. It works over bash#When you have run that shell script, it should automatically restart your vm1.#Login to your vm1.#Use the SSH protocol so commands taught in this lab to confirm if you have ssh working - you can use rsync as wellyour network connection is broken.#Carefully check your configuration to see if there is a change to your settings#Try to temporarily connect to the Internet#Edit your network settings file to make the changes permanent#Test your connectivity (including after a reboot of your vm1)

'''Note:''' Youshould be able to go through that troubleshooting process pretty quickly. Setting up the network in this course is never a primary task, but it's almost always a prerequisite for anything else we're going to use your host machine to backup files from the virtual machinesdo. To make it simpler we wonYou can't have a working web server (or any incremental backups and the backups will be automated so other kind of server) if you don't rely on these too much, but they may save you some time over the many weeks in this coursehave a working network connection.

<source lang=bash>mkdir '''Record steps, commands, and your observations in INVESTIGATION 1 in your OPS335 lab log-p /backup/vm1rsync -avz 192.168.x.2:/etc /backup/vm1/</source>book'''

If rsync asked for a password - make sure you completed the == INVESTIGATION 2: Configuring SSH keys part of the lab, and that you're using the correct user. If you get a different error - perhaps rsync is not installed. What you should see is all the files from vm1 being copied over.==

Rerun The default (and often the commandonly way) to administer a Linux server is via SSH. Even if you work in a graphical Linux environment, it is very useful to open a terminal and use SSH to monitor and manage your VMs (you can resize the terminal window). Using SSH to connect to remote servers on a network helps to protect your Linux machine from being penetrated. Notice that You can also generate a private and public encryption key for the second time nothing is copied over - root user, and copy that's because there would public key from your host to your VMs in order to allow certain backup programs to run via a scheduling daemon (called cron) without having to be no point, none of required to enter the password for the files have changed on vm1remote machine. You will be doing those operations later in this lab.

Every user has a crontab - a list of tasks they want to run periodically. You edit this table using the command '''crontab -e'Perform the following steps:''. Once you run the command you'll get an empty file where you have to insert a line like this:

<pre>10 * * * * echo "Cron ran this job at# Note the following [http: "`date` > /tmp/cronzenit.log<senecac.on.ca/wiki/index.php/pre>Init_vs_systemd#systemd_Command_Usage systemctl] commands (refer to man pages or the Internet) and become comfortable using them:

This tells cron to run the command ::* '''systemctl list-units --all'echo "Cron ran this job at'': "`date` > :* '''systemctl start/tmpstop'''::* '''systemctl enable/cron.logdisable'''::* '''systemctl status''' at the 10th minute of every hour of every day of every month. Modify the setting so it will run in a couple of minutes from now and insert that into your crontab.

Wait for <ol><li value="2">Launch your '''vm2''' machine, login to the minute to passmachine, and open a shell terminal.</li><li>Use one of the commands above to check the status of your SSH server (i.e. service: ''sshd'').</li><li>Issue one of the above commands to stop of the ssh server and run a command to verify that the ssh server is no longer running.</tmp/cron.log was created with li><li>Issue another one of the above commands to start the expected contentsSSH server and to verify that it is running. You can also check /var</log/cron li><li>Issue a command to see what jobs were confirm that the ssh service will runupon when the vm2 server restarts (i.e. "enabled").</li></ol>

'''Your task:''' set up cron to make automatic backups of ===Configuring the /etc directory from vm1, vm2, and vm3 into /backup/vm1, /backup/vm2, and /backup/vm3. These should run every hour and overwrite the previous backup. Which makes them lousy backups but they're better than nothing.SSH Service===

= Completing A common (if somewhat blatant) way to try to hack into a machine is to try to ssh as '''root''' and brute-force root's password. The root user always exists, meaning the lab =attacker doesn't need to try guessing what user names are on your system. If they can get access to root, they can do anything. To prevent this, we will edit the configuration file for the ssh service to prevent root from ssh'ing into your host machine.

 '''Perform the following steps:''' #Login to your Centos '''host''' machine for the following steps.#Use the more command to display '''/etc/ssh/sshd_config''' on your host. This file contains the configuration parameters for the ssh service.#Take a few moments to view this file. Lines that begin with # are comments. Either simple explanations of parameters, or parameters that have not been set.#Open the man page for '''sshd_config'''. This lists all the possible parameters in alphabetical order along with a brief explanation of what each one does. The parameter we are looking for is '''PermitRootLogin''', read its description.#Use a text editor to edit the file '''/etc/ssh/sshd_config''', and find the line that has '''PermitRootLogin'''. By default it is set to yes, allowing the root user to ssh in to the machine.# Uncomment '''PermitRootLogin''', and change the value to '''no'''.#Try to use ssh from one of your VMs to log into your host as root. What happened?#This is because (for most services) the '''changes you make to the configuration file will not take effect until the service restarts'''.#Restart the sshd service on your host and try to ssh in again. Now it should prevent you.#The option '''PermitRootLogin''' for '''all of your VMs''' for both labs and assignments MUST be set to '''yes'''. The reason for this is that you have created a virtual network, so you have protected the host from root login, so you don't have to do the same for your VMs. Also, by allowing root login for your VM's will allow you to automatically backup your VMs to your host machine (via a crontab entry) without being prompted for a root password for each VM. '''Note:''' Configuration files for most services follow a very similar format. Some use an = between the parameter and its value, some require you to group certain parameters together, and most use # to be a comment. You will get lots of experience working with the configuration files for services in this course. === SSH Key Concepts=== After performing lab7 in OPS235, you should have a basic understanding of ssh and public/private key cryptography to create secure connections between servers.<br>The public key can be "shared" with other server accounts, and can be used in conjunction with your private key in order to help encrypt/de-crypt data.  The diagram below is shared from [http://sebastien.saunier.me/blog/2015/05/10/github-public-key-authentication.html Sébastien Saunier's blog].It demonstrates how SSH key authentication works. It's not a complete diagram, but it helps see all the parts of ssh key authentication in one place. [[Image:ssh_connection_explained.png|thumb|center|600px|A diagram explaining how public / Private keys work. Another term to represent this process is called '''PKI''' (Public/Private Key Infrastructure) ]]<br />Put this book on your "must-read" list. You can borrow a copy from the Toronto Public Library. I have yet to see a better introduction to encryption. It's not a reqirement for OPS335 - but if you want to not be clueless about security fundamentals online - read that book and understand it. [[Image:crypto.jpeg|center|"crypto" by Steven Levy]] === Generating a Public/Private Key Pair &amp; Sharing the Public Key === The public/private key pair needs to be generated on and used on your '''host''' machine (i.e. the user/machine you're connecting '''from'''). The private key is the equivalent of a <u>''password''</u> (that is why it is considered to be <u>''private''</u> - only to be used by ''<u>one</u>'' owner). That is why the private key is stored in the owner's '''~/.ssh/''' directory. One very common mistake that students make is to either generate the key pair for the wrong account, or copy the public key to the wrong account on the intended remote machine. '''Perform the following Steps:''' # Make certain you are in your '''host''' machine.# You will be creating a '''key-pair on your host machine with no password''' (i.e. when generating keypair press enter for all prompts including the password).#Make certain you are logged on as '''root''' on your host machine.# Generate the key-pair by issuing the command:<br><source>ssh-keygen -t rsa</source> '''NOTE:''' When issuing this command, you will end up with the files: '''~/.ssh/id_rsa''' and '''~/.ssh/id_rsa.pub''' (private and public keys). So far, this topic is generally a repeat of OPS235 lab7. What you may '''<u>not</u>''' know is that by using a '''"trick"''' (the ''magic'' of public key cryptography), you can SSH to a Linux machine without using a password! Learning to perform this trick is <u>'''essential'''</u> in this course and in the industry in general. SSH keys are used everywhere that Linux servers are used. If you have the private key, you can prove to someone who has your public key that you are indeed the '''actual owner of that public key'''. That is how ssh key authentication works. You are then only required to transfer your public key to a remote server. <ol><li value="5">You are going to share the public key from the '''root user in your host machine''' with the '''root user of your vm1 machine'''.</li><li>Copy the contents of your '''~/.ssh/id_rsa.pub''' from your host machine and append to '''~/.ssh/authorized_keys''' on each of your Virtual Machines. In your case, you will issue the following command 3 times (for each vm IPADDR):<br><source>ssh-copy-id -i ~/.ssh/id_rsa.pub root@IPADDR_for_vm</source>'''NOTE:''' Press ENTER for all prompted information including the password (although this may seen counter-intuitive!).<br><br></li><li>Use the ssh command to test each ssh connection between your host and each virtual machine that you can connect to the VMs without having to use a password. This is essential to create backups from VMs to your hostmachine without being prompted for password.</li></ol>  {{Admon/important|Errors in Copying Public Key from Host to VM|If you experience an error when copying the public key from your hostmachine to your VM, it is most likely caused from not permitting root login that you performed in the previous section. Set to allow login from root for each vm, restart your sshd service and then re-run the above command.}}  After you perform either of those operations, you can then ssh into a remote vm without a password. '''NOTE:''' Always remember that these keys are '''per-user, <u>not</u> per machine'''. This means that sharing a user's public key will only work for that specific user. == INVESTIGATION 3: PERFORMING &amp; AUTOMATING BACKUPS == Data backups are considered to be an insurance policy. Running backup can be tedious, but they MUST be performed in an accurate and consistent basis, since loss of data can be expensive (For example: cost of hiring staff to re-enter data). When performing labs or assignments in this class, if you fail to make backups and something bad occurs and there is loss of data, it only affects you. On the other hand, if you are supporting a client, or working for a company and fail to adequately perform backups and there is loss of data, then other users are affected by failure to backup essential data.  === Performing Full Backups === A full backup represents backing up of all of the files of a computer machine (in our case, a VM). A full backup should be performed at the end of each lab or assignment working session. In OPS235, you learned to use the command '''gzip''', '''gunzip''' (plus'''virsh dumpxml''' / '''virsh define''' if backing up to external storage device like a usb key) to backup your virtual machines. We will use the same method to perform a full backup for these labs and assignments. '''Perform the following steps:''' #Make certain that your virtual machines are NOT running.#Make certain that you are logged in as '''root''' user on your host machine.#Refer to OPS235 lab2 on backing up your VMs using the '''gzip''' command [https://wiki.cdot.senecacollege.ca/wiki/OPS235_Lab_2_-_CentOS7_-_HD2#Part_1:_Backing_Up_Virtual_Machines OPS235 Lab2 - Backing up VMs]#Make certain that you have performed a full backup for '''vm1''', '''vm2''', and '''vm3'''. It is recommended to create a Bash shell script to automate the backing up of ALL your VMs in sequence. You can do this by running a for loop using a list for vm1, vm2, and vm3 image file pathnames. <ol><li value="5">Create the sub-directory '''/root/bin/'''</li><li>You should know how to create full backups of your VMs in your OPS235 course. Create a Bash shell script called:<br>'''/root/bin/fullbackup.bash''' that will backup all of your other vms (i.e. vm1, vm2, and vm3) one at a time using the '''gzip''' command to your host machine into the directory path-name: '''/backup/full/'''</li><li>Set execute permissions, and run the shell script to verify that you shell script works.</li><li>It is also recommended to backup to your USB key as well (qcow2 images and xml config files).</li></ol>  It will be your responsibility as an administrator of your own Linux system, to backup all of your VMs for labs and assignments at the end of your lab session. Learning to create shell scripts to automate routine tasks (such as backups) will be EXTREMELY useful for your NDD430 course. === Performing Incremental Backups === An incremental backup is a backup of only files that have changed since the last backup. In your case, it may be a good idea to perform incremental backups of your '''/etc/''' directory for your VMs upon startup. We will be using the '''rsync''' command to perform incremental backups for all of your VMs. '''Rsync''' is a very versatile backup tool. As the name suggests, rsync is used for <u>synchronizing</u> files typically across a network. It works over the '''SSH''' protocol, which is useful in our situation since we are running ssh on our server and VMs. You are going to use your ''host machine'' to backup files from the ''virtual machines''. '''Perform the following steps:'''  {{Admon/important|Rsync Needs to be Installed on ALL VMs |Since you select minimum install on your VMs, the rsync command was not installed by default. You need the rsync command to be available on your host machine and all of your VMs. Make certain that the '''rsync''' command is installed on all your vms. }}  # Make certain that your '''vm1''' machine is running.# Make certain that you are logged in as '''root''' user on your host machine.# On your '''host machine''', run the following commands: <source>mkdir -p /backup/incremental/vm1rsync -avz 192.168.x.x:/etc /backup/incremental/vm1/ # where 192.168.x.x is the IPADDR of your vm1</source> '''NOTE:''' This command will '''NOT''' work if '''permit root access is denied for your VMs''' for your sshd service configuration, so keep it off for now... <ol><li value="4">If rsync prompts for a password, make certain that you completed the '''SSH key''' section above, and that you assigned the keys for the <u>appropriate user</u><br>(in this case, for the '''root user for both the hostname and vm1'''!)</li><li>When the rsync command runs correctly, you should see all the files from vm1 being copied over to your host machine.</li><li>Run the rsync command again. Notice that the second time nothing is copied over to your host machine since none of the files have changed on your vm1 machine.</li><li>Create a new file in vm1's '''/etc/''' directory, and rerun '''rsync'''. Confirm on your '''host machine''' that only that file that was created on your vm1 machine actually got backed up to your host machine.</li><li>Repeat the above steps to create backups for your '''vm2''' and '''vm3''' machines on your host machine as well (for the respective directories: '''/backup/incremental/vm2''' and '''/backup/incremental/vm3''').</li></ol> === Automating Backups (cron) === Since your host machine and VMs are '''not continuously running''', '''you are not required to schedule to perform your FULL BACKUPS periodically''' (eg. every week at 2:00 AM). Instead, it will be YOUR responsibility to run your full backup script when you complete each of your OPS335 labs, or when you finish your OPS335 assignment working session. On the other hand, '''you will use cron to perform incremental backups''' (eg. copy updated files from the VMs/ /etc/ directory)  '''Cron''' is a ''daemon'' (i.e. a program that runs in the background). The term ''"Cron"'' is short for '''Chronograph''' which was an old fashioned term for a '''stop watch''' or '''timer'''. The role of '''Cron''' is to run tasks periodically. It can run tasks for the system (as root) or for a user (including regular users). Every user has a crontab (Cron Table) which is a list of tasks they want to run periodically. You do not edit this file manually: instead, you edit this table using the command '''crontab -e'''. Once you run the command, you will get an empty file where you have to insert a line like this: '''Perform the following steps:''' # Refer to the following WIKI to learn how to use cron: [[crontab tutorial]]# In your host machine as root, modify the setting so it will run that echo command every minute by creating a crontab (via '''crontab -e''') entry with the following line:<br><source>* * * * * echo "Cron ran this job at: "`date` >> /tmp/cron.log</source># Save and exit your crontab edit session.# Wait for one minute to pass, and check the '''/tmp/cron.log''' file to see if it was created with the expected contents.<br>(You can also check '''/var/log/cron''' file to see what jobs were run).# Perform a Net-search to see how to configure that crontab entry to run every two minutes instead of every minute.# Edit your crontab entry to run same command every two minutes, save and exit, and then confirm by viewing '''/tmp/cron.log''' and '''/var/log/cron''' files.# Perform a Net-search to see how to run a cron for a command for every hour.# Edit your crontab to '''make automatic backups using the rsync command''' of the '''/etc''' directory from '''vm1''', '''vm2''', and '''vm3''' into '''/backup/incremental/vm1''', '''/backup/incremental/vm2''', and '''/backup/incremental/vm3''' every hour and overwrite the previous backup.   {{Admon/important |Backup your VMs!|You MUST perform a '''full backup''' of ALL of your VMs whenever you complete your '''OPS335 labs''' or when working on your '''OPS335 assignments'''. You should be using the gzip command, and you should use the Bash shell script that you were adviced to create in order to backup all of your VMs.}}  '''Record steps, commands, and your observations in INVESTIGATION 2 in your OPS335 lab log-book''' == COMPLETING THE LAB == ===Online Submission=== Follow the instructions for lab 1 on blackboard. <!--===Andrew's sections=== You may choose to:* Submit screenshots of your work on Blackboard, in which case you don't need to come to the lab.* Or come to the lab, show me your work, and talk to me about it. I want to hear what you've learned and answer any questions you have. You'll get the same grade regardless of how you choose to submit your work. Expected results of this lab are: ::<span style="color:green;font-size:1.5em;">&#x2713;</span> Each of your VMs should now boot to a command prompt (no graphical interface), and should be using a static IP address. * ::<span style="color:green;font-size:1.5em;">&#x2713;</span> Each of your VMs should have a working network connection and a static IP address.* ::<span style="color:green;font-size:1.5em;">&#x2713;</span> Each of your VMs should have an SSH server running.* You ::<span style="color:green;font-size:1.5em;">&#x2713;</span> should be able to ssh from your host to each VM as the root user without a password.* Backups ::<span style="color:green;font-size:1.5em;">&#x2713;</span> Display contents of the three VMsbackup script called: ''' /etcroot/bin/fullbackup.bash'''::<span style="color:green;font-size:1.5em;">&#x2713;</ directories are made automatically in the hostspan> Full and incremental backups of your 3 VMs.* ::<span style="color:green;font-size:1.5em;">&#x2713;</span> You have notes in your labbook lab-book about what you've learned in this lab.::<span style="color:green;font-size:1.5em;">&#x2713;</span> Run a shell script : http://matrix.senecac.on.ca/~murray.saul/ops335/labcheck_network_backup.sh--> == EXPLORATION QUESTIONS == # Explain the major different between the '''ip''' and '''ifconfig''' commands.# List the steps to create a '''temporary static IP network connection''' for your vm1 machine to connect to your host machine.# List the steps to create a '''persistent static IP network connection''' for your vm1 machine to connect to your host machine.# List at least '''3 trouble-shooting techniques''' to check or verify a network connection from a vm to a host machine.# List at least '''5 reasons''' (from networking trouble-shooting) that can break a network connection.# List the tools (commands) how to configure / stop / start the ssh service.# Explain why it is important to know how to manage network services if you intend to configure ("tweak") the service.# Briefly explain the purpose of the '''tar''', '''cpio''', '''dump''', '''restore''' commands.# Explain how the '''rsync''' command differs from the ''tar'', ''cpio'', ''dump'', and ''restore'' commands.# List the steps to create a '''crontab''' entry to run the program '''/bin/clean-out.bash''' every half day.# What is the purpose of using '''crontabs''' for backing up your virtual machines' data to your host machine?