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OPS235 Lab 4 - Fedora17

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[[Category:OPS235]][[Category:OPS235 Labs]]
= State when starting Lab 4 =
=Working with Partitions At this point, having completed [[OPS235 Lab 3|Lab 3]] you should have <u>roughly</ User &amp; Group Management=u> the following disk storage setup:<br />('''Note:''' These results are output from the '''vgs''', '''lvs''', and '''pvs''' commands within each virtual machine. You will be using these commands in the following lab investigations)<br /><br />
==Introduction==* '''fedora1'''
:* In this lab, you are going to learn how to create This VM has a GUI and format partitionsno free space in the VG. You will be creating partitions by using both graphical and command VG #PV #LV #SN Attr VSize VFree vg_fedora1 1 2 0 wz--n- 9.80G 0 LV VG Attr LSize lv_root vg_fedora1 -wi-ao 8.83G lv_swap vg_fedora1 -wi-ao 992.00M PV VG Fmt Attr PSize PFree /dev/vda2 vg_fedora1 lvm2 a-line utilities 9.80G 0
:* Also in this lab, you will learn how to manage (add, delete, modify) user accounts on your Fedora systems. You will also learn how to create and maintain groups to allow users to share and protect data.'''fedora2'''
==Objectives== This VM has a GUI and free space in the VG. VG #PV #LV #SN Attr VSize VFree vg_fedora2 1 3 0 wz--n- 14.80G 4.07G LV VG Attr LSize lv_home vg_fedora2 -wi-ao 1.95G lv_root vg_fedora2 -wi-ao 7.81G lv_swap vg_fedora2 -wi-ao 992.00M PV VG Fmt Attr PSize PFree /dev/vda2 vg_fedora2 lvm2 a- 14.80G 4.07G
#Learn about partitions, and how to create and format them without using LVM#Identify and define major entries in the <code>/etc/passwd</code>, <code>/etc/shadow</code>, and <code>/etc/group</code> files.#Learn how to add and remove and modify user accounts.#Learn how to create and manage groups.* '''fedora3'''
== Required Materials (Bring to All Labs) == This VM has no GUI installed. VG #PV #LV #SN Attr VSize VFree vg_fedora3 1 3 0 wz--n- 9.80G 3.83G LV VG Attr LSize lv_home vg_fedora3 -wi-ao 1.00G lv_root vg_fedora3 -wi-ao 4.00G lv_swap vg_fedora3 -wi-ao 992.00M PV VG Fmt Attr PSize PFree /dev/vda2 vg_fedora3 lvm2 a- 9.80G 3.83G
* Fedora 17 LIVE CD* Fedora 17 x86_64 Installation DVD* SATA Hard Disk '''f13host (in removable i.e. "disk traypack")* USB Memory Stick* Lab Logbook'''
==Prerequisites== Four PVs, minimum VG size 60G Single filesystem on vg_main/root, size 50G At least 10G available space in VG 20% of disk space unallocated to any partition (min 15G)
* Completion and Instructor "Sign-off" of Lab 3: [[OPS235 Lab 3]]= Logical Volume Management =
{{Admon/note|Recovering VMs|'''Most of these investigations will take place in you virtual machines.''' If you make a significant mistake, your virtual machine may not boot. Remember that you created backups of your virtual machines in Lab 3, and you can '''restore them if something goes wrong'''.}}
==Linux Command Online ReferenceResources ==Each Link below displays online manpages for each command (via []):
{|width="100%" cellpadding="5"|'''Partition/Filesystem Management UtilitiesPlease read this page to get an overview of LVM:'''|<br /><br />('''User/Group ManagementNote:'''||- valign="top"|*[http://linuxmanpagesIt is recommended to return to this guide as a reference when performing the next several investigations).com<br /man8><br /fdisk.8.php fdisk]>*[ cfdisk]*[ mkfs.ext3]*[ mount]*[ umount]|* [ /etc/passwd File]* [ /etc/skel File]* [ /etc/group File]*[ useradd]*[ userdel]*[ usermodLogical Volume Management]*[ groupadd]*[ groupdel]*[ chmod]
== Investigation 1: How are LVMs are managed using system-config-lvm? =='''Perform this investigation on the VM named ''<u>fedora2</u>''.'''[[Image:Ops235_lab4_1.png|}thumb|right|Screenshot of system-config-lvm in Fedora. Click to enlarge.]]# Let's learn to manage or administer our LVM graphically for our Virtual Machine ('''Fedora2''').<br />Fedora provides a tool called <code>system-config-lvm</code> to graphically administer LVM. It will appear on the menu as System>Administration>Logical Volume Management. Verify that this package is present, and install it if required (<code>yum install system-config-lvm</code>).# Use this tool to determine the current LVM configuration by clicking on the appropriate element and reading the properties in the right-hand panel -- write down the answers:#* What are the names and sizes of the PVs?#* What is the name and size of the VG?#* What are the names and sizes of the LVs?#* Is there any space in the VG which is not allocated to a LV?# Increase the size of the home filesystem to 2 GB:## Click on the LV containing the home filesystem.## Click on ''Edit Properties''.## Change the size to 2 GB and click ''Ok''.# Create a new 2G LV (LV Properties: linear) containing an ext4 filesystem named lv_archive and mount it at /archive## Click on ''Logical View''.## Click the ''Create New Logical Volume''.## Set the name, size, filesystem, and mount point.## Click ''Ok''.# Backup <code>/etc</code> into <code>/archive</code>#* Copy the files in /etc into the filesystem mounted at <code>/archive</code> (use the graphical tools or the command line. If using cp, remember to use the -R option).# Shrink the size of <code>lv_archive</code> to 1 GB.# Try shrinking <code>/</code> -- what happens? Why?
==Resources on the webInvestigation 2: How are LVMs are managed using Command-Line Tools ==Additional links # You are going to repeat the same LVM management operations (as your did with the ''fedora2'' VM), but you will using command-line tools in the '''fedora 3''' VM. Since the fedora3 VM only operates in command-line mode, you will need to tutorials refer to the '''"Logical Volume Management"''' link above.# Write down the exact commands used at each step, and HOWTOsrecord appropriate command output:## Determine the current LVM configuration using the <code>pvs</code>, <code>vgs</code>, and <code>lvs</code> command.## Grow the home filesystem to 2G using the command <code>lvextend</code> and <code>resize2fs</code>.## Create a new 2G LV containing an ext4 filesystem and mount it at /archive (use <code>lvcreate</code>, <code>mkfs</code>, <code>mount</code>, edit the file <code>/etc/fstab</code>, and then reboot to confirm automatic mount).## Copy the contents of <code>/etc</code> into <code>/archive</code>.## Shrink <code>lv_archive</code> to 1G (use <code>umount</code>, <code>resize2fs</code>, <code>lvreduce</code>, and <code>mount</code>)
== Investigation 3:* [[Logical Volume Management]] How can a PV be added to an existing VG? =='''Add an additional 2 GB virtual disk to your ''<u>fedora1</u>'' system, and use it as an additional physical volume:* [http:'''# Start <code>virt-manager<//tldpcode>.org/HOWTO/Partition/fdisk_partitioning# Shutdown ''fedora1'' if it is running.html Partitioning with fdisk]:*[http://gparted# Open the console window for ''fedora1''.sourceforge# Select the menu option View> Click ''Add Hardware'' button at the bottom left-dochand corner.php?# In the ''Adding new virtual hardware'' window that appears, select a Hardware Type of ''"storage"'' and click ''"Forward"''.# Make certain option "Managed or other existing storage" is selected. Click on the ''Browse'' button, then click on ''New Volume''.# Give the new virtual disk file a name=help-manual Gparted Manual]of <code>fedora1b</code>, a format of ''raw'', with a ''Max Capacity'' and ''Allocation'' of 2000 MB. Click ''Finish''.# Select the new virtual disk file ''fedora1b.img'' and click ''Choose Volume''.# Select a device type of ''Virtio Disk''.# Finish creating the new virtual disk by clicking ''Forward'' and then ''Finish''.:* [http:# Boot the system. You should now have both <code>/dev/vda</code> and <code>/dev/vdb</wwwcode>.linux-tutorial# Record the size of the volume group and the amount of free space (Hint: use a command that you learned in a previous lab).info# Partition /dev/modulesvdb with a single partition that fills the whole disk.php?name=MContent&pageid=282 Mounting # Check the messages printed when <code>fdisk</ Unmounting Filecode> exits -systems]- you may need to reboot the system in order for the new partition table to take effect.# Run this command to format the physical volume:* [http:<code>pvcreate /dev/''vdb1''</viewcode># Add the new physical volume to the existing volume group: <code>vgextend ''nameOfVolumeGroup'' /14446dev/53vdb1</ UID code># Verify that the volume group is larger and GID explained]has more free space.
= Creating {{Admon/ Formatting note|Think!|The next part of this investigation requires some research, thought, and creativity.}}'''Using that additional space, create a separate filesystem for <code>/ Mounting Partitions =home</code>:'''# Create the logical volume <code>lv_home</code> (1G ext4)# Find a way to move the contents of <code>/home</code> onto it.# Change your system configuration so that the new filesystem is mounted on <code>/home</code> from now on.
== Investigation 1: Create partition {{Admon/tip|SELinux relabelling may be required|Your system may report that the files are not present in the new /home filesystem when they are clearly there. This is due to the Security-Enhanced Linux system (SELinux) preventing access to the files, because the files were tampered with (Graphical Methodmoved) ==and are no longer recognized as home directory content. You can fix this problem by restoring the file context labels so that SELinux accepts the files as valid home directory content: <code>restorecon -r /home</code>}}
== Investigation 4: How can I use LVM to manage storage on my disk pack? =='''Perform this investigation on fedora1 On your <u>f13host</u> (i.e. "disk pack"), using your choice of the GUI and fedora2/or command-line tools:'''# Create a new logical partition ('''NOT a logical volume!''') - minimum 5G, leaving at least 10G free space in the extended partition.# Add that partition as a PV into the existing VG (using the commands you used in the previous investigation).# Grow the root filesystem to fill the available space.
# Make sure that on both virtual machines you have system-config-lvm and gparted installed. If you finished lab3 - you should have system-config-lvm on fedora2, but you still have to install it on fedora1.# In the end of the last lab we used the graphical tool system-config-lvm to create a logical volume lv_archive. Examine the logical and physical volumes on fedora2 using system-config-lvm.# Run gparted. Gparted will only list traditional partitions, not any LVM information. Note that in Gparted there is a dropdown box for the drive currently displayed. Look for common elements that are displayed in both programs.# Just as we added a new physical drive to fedora3 in lab3 - go to the hardware details (in the virtual-manager application) in fedora1 and add a new hard disk of 2GBs, make sure it's a VirtIO disk.# Instead of adding it to the volume group for use with LVM we're going to create a traditional partition on it, and a filesystem on that partition:## Run gparted on fedora1 and select the new drive, if you added it correctly it should be /dev/vdb.## Create a new partition using up all the space (approx. 2GB) with an ext4 filesystem, with the label '''archive'''. Don't call it lv_archive since it's not a logical volume.## Gparted may not allow you to create a partition because the drive has not been initialized. Create a partition table as the tool tells you to do, then create the partition.## When you're ready to apply the changes - click the "Apply all operations" button.# Run system-config-lvm on fedora1. Do you see the archive partition you created?# Go back to gparted and shrink the /dev/vdb1 partition to be 1GB in size. Don't forget to apply the changes.# Spend some time looking at the drive/partition/physical volume/logical volume details in gparted and system-config-lvm on fedora1 and fedora2 - by the end of this lab you should be able to explain everything in all of the views for these applications.= Package Management =
'''You need to be comfortable with these concepts on tests - make useful notes in your lab log book.'''== Investigation 5: How do you query the RPM database? ==
== Investigation 2RPM maintains a database of installed software. This information is very useful to system administrators. In Lab 3, you queried that database using RPM with the -q argument. When you query the RPM database, you can separately specify: Create partition (command* Which packages you want information about, using a select-option* What information you want about those packages, using a query-line method) ==option
'''Perform this investigation on fedora1.'''Steps:
# There are two command-line programs that can be used 1. Using information from the man page for working with partitions on linux: fdisk (something rather unique) and cfdisk (something like the old DOS fdisk<code>rpm</code>, if that means anything to you). cfdisk is easier to use, but fdisk is available on more systems by default. You can choose either tool for completing fill in this investigation.information:{|width="100%" border="1"|-!Option!Meaning# Give the full path to the hard drive device (vdb) as the first parameter to fdisk. If you don't understand what !Is this means a select- you may want to do option or a review of some parts of ULI101.query-option?|-# Create | -a new primary partition on the drive, using up |Select all the available free (unpartitioned) space. Tip: in fdisk use the packages|select-option|-| -l| | |-| -p ''filename'h' command to get a list of all available commands.# Don't forget to save your changes.# Now we have a partition /dev/vdb2. But there is no filesystem on |Select this partition yet. We need to create a filesystem (both systemuninstalled package| |-config| -lvm i|Show the package license, packager, URL, description, and gparted did the following step automatically): <code>mkfsother general information.ext4 /dev/vdb2 | |-| -L archive2</code>f '''filename'''| # Run gparted again, look for the changes that happened after you created the partition/filesystem.| |-|'''Will you remember how to use fdisk or cfdisk and mkfs? Make notes in your lab log book.packagename'''|Select just this package|select-option|}
== Make sure that your lab notes answer the Investigation 3: Manually Mounting / Unmounting Filesystems ==5 question.
'''Perform this investigation on the VM named ''<u>fedora1</u>''.'''== Investigation 6: How do you install and remove software with RPM? ==
So far, we have simply assumed that when # Change to the directory on your Installation DVD containing the Fedora OS bootsfile: <code>lynx-up, that its file2.8.7-system is automatically available2.fc13.x86_64. In rpm</code># Execute this investigation, you will learn how filecommand: <code>rpm -i lynx-systems (or portions of file2.8.7-systems) can be mounted or "connected" 2.fc13.x86_64.rpm</code># Issue an RPM query to existing filecheck that lynx is installed.# Issue this command: <code>rpm -systemse lynx</code># Issue an RPM query to verify that lynx is no longer installed. You will also learn how to unmount (or "disconnect") portions of file# Issue this command: <code>rpm -i BackupPC-systems from existing file3.1.0-systems13.fc13.noarch.rpm</code> and note the result
# Issue Answer the command called '''mount''' . This command provides information relating to various partitions (logical volumes) and corresponding "mount points" (directories).# Record the information from issuing the <code>mount</code> command for '''lv_root'''. Can you write the command that will quickly find just the line you're interested in from all the output of the mount command? You need to know this (from ULI101).# Create the directories /archive and /archive2# Issue the commands '''mount /dev/vdb1 /archive''' and '''mount /dev/vdb2 /archive2'''. Did anything happen? Issue the '''mount''' command again. Is there any difference with the command output?# Copy some files to /archive and /archive2, then unmount the two partitions. After the unmount is successful - look at the two directories. Where did your files go?# Note that CD/DVD disks also need to be mounted for you to access files on them. Try mounting a DVD manually (without using the GUI) on our host - you'll need to use the mount command, and know the device name of your drive (it's probably /dev/sr0)Investigation 6 question.
== Investigation 7: How do you install and remove software with ''yum''Do you know how to use the mount/umount commands? Make notes in your lab log book.'''==
== Investigation 4: How Partitions are Automatically Mounted Upon Boot-up =={{Admon/note|Internet Connection|In order for yum to work you require a connection to the Internet. Establish this connection by using the browser to log into SeneNET}}
'''Perform this investigation on fedora1# Change to your home directory.'''
#Check Issue the man page for command: <code>/etc/fstabyum install BackupPC</code> by entering the command and answer <code>man fstaby</code>to the question about installation.#* Where did ''yum'' get the BackupPC software?#* Why could ''yum'' install BackupPC when rpm couldn't?#Edit your <code>/etc/fstab</code> file Issue an RPM query to mount verify that BackupPC is installed.# Issue the partitions command: <code>/dev/vdb1</code> and <code>/dev/vdb2yum remove BackupPC</code> # Issue an RPM query to verify that BackupPC is no longer installed.# Install <code>'''/archive'''nled</code> and <code>using '''/archive2yum'''</code>.#Issue this command:::<code>mount -ayum info cups</code><ol> <li value="5">What does #* Based on the result, do you think that command docups is a useful package for your system?</li> <li>Confirm that the partitions mountedIf not, try removing it.</li> <li>Issue # Unused and unneeded software can present a command to list the contents of '''/archive''' security risk and ties up disk space needlessly. Find at least 4 other packages that you'''/archive2'''. Are there any files? <li>Reboot the fedora1 VMre not using on your system, and verify remove them. Be careful to ensure that removing those packages does not also remove other software that '''/archive''' and '''/archive2''' have now been automatically mountedyou do need.</li></ol>
'''Make notes about Answer the format of the lines in fstab in your lab log bookInvestigation 7 question.'''
= User/Group Management =
== Investigation 58: The /etc/passwd file == '''Perform this investigation on the VM named ''<u>fedora1</u>''.'''
# Look at the /etc/passwd file.
# Make note of the contents of that file.
# Read about the file:
# Now look at the contents of the '''/etc/passwd''' file.# Make note of the contents of that file, and make certain and record in your lab log-book the sure you know what information that each field contains.
# Why do you think there are so many users?
# Look at the names of the users. What do you think these user names represent? Are they people?
# The user IDs of real users (people) are different from the user IDs of system accounts. What is the pattern?
'''Answer the Investigation 5 observations / questions in your lab log book.'''  == Investigation 69: Adding users ==
'''{{Admon/note|Use f13host|Perform this investigation on these steps in the VM named ''<u>fedora1</u>''.f13host'''system. Due to a configuration issue, these steps may not work normally in the fedora1 virtual host (previous versions of this lab used fedora1 for this investigation).}}
# Read the man page for the '''useradd''' command.# Create a new user account for each of your pod-mates, using their learn account name as a user name. Give each user a password.# Use Grep the grep command to obtain information /etc/passwd file for each of the newly created new users within the '''/etc/passwd''' file.
#* What is the home directory of each user?
#* What group is each user in?
#* Grep the /etc/shadow file for each of the new users.
#* Make note of this information.
#* What is the purpose of the /etc/shadow file?
# Create two new dummy users, ops235_1 and ops235_2.
# Investigate the home directory of one of your new users.
#* What files are there? Be sure to include hidden files.
#* What do you think these files are used for <span class="plainlinks">?#* How does the operating system determine which files are created in a new home account? <br />The answer can be found here:
#* Look at the files (including hidden files) in the template directory referred to in the article. Compare them to what is in a home directory for a new user. What do you notice?
#* Create a new file in this directory with the following command: <code>touch foo</code>
#* Create a new user named foobar, with the option to automatically create a home directory.
#* Look at the contents of foobar's home directory. What do you notice?
# Be sure to record your observations in your lab notes.
<ol> <li value="7">Boot-up your {{Admon/note|Use fedora3|Perform these steps in the '''fedora3''' VMvirtual machine.</li>}} <li>Create a new user using # Add your '''Matrix''' matrix account user-name.</li> <li>Issue a command to verify that you have created this user account.</li></ol> '''Answer the Investigation 6 observations / questions in your lab log book.fedora3'''.
== Investigation 710: Managing Groups ==
{{Admon/note|Use fedora1|Perform these steps in the '''fedora1''' virtual machine.}}
<ol><li># Read the man page for the '''groupadd''' and '''groupdel''' commands.</li><li># Note which option allows you to set the Group ID number (GID) when you create a new group.</li><li># Examine the file <code>/etc/group</code><ol type="a"><li>#* Which values of GID are reserved for system accounts?</li><li>#* Which values of GID are reserved for non-system user accounts?</li><li>#8 What is the lowest available GID number for non-system users?</li><li>#* What is the default group name of a new user?</li><li>#* Add a new group named <code>ops235</code> with a GID of <code>600</code>.</li><li>#* You are angry at some irresponsible users on your system. <ul><li>#** Add a new group named <code>idiots</code>.</li><li>#** Look at <code>/etc/group</code> and note the GID of idiots.</li><li>#** What GID is given to a new group if if you do not specify it?</li><li>#** Your anger has subsided. Delete the <code>idiots</code> group.</li><li>#** Look at <code>/etc/group</code> again and note the change.</li></ul></li></li></ol></li></ol>
Be sure to record your observations in your lab notes.
'''Answer the Investigation 7 observations / questions in your lab log book.'''  == Investigation 811: Deleting users ==
{{Admon/note|Use fedora1|Perform these steps in the '''fedora1''' virtual machine.}}
# Read the man page for the '''userdel''' command. Note which option automatically removes the users home directory when that user is deleted.
# Delete the user ops235_1 using the command <code>userdel ops235_1</code>
# Delete the user <code>ops235_2</code> using the same command with the option which removes the home directory of the user.# Check the contents of the <code>/home</code> directory. What do you notice?# Check the contents of the <code>/etc/group</code> directory. What do you notice?
'''Answer the Investigation 8 Be sure to record your observations / questions in your lab log booknotes.'''
== Investigation 912: Modifying users ==
{{Admon/note|Use fedora1|Perform these steps in the '''fedora1''' virtual machine.}}
'''Perform this investigation on # Read the man page for the usermod command. Note which options change the VM named ''<u>fedora1</u>'user's full name, primary group, supplementary groups, and shell.'''
# Read the man page for the '''usermod''' command. Note which options change the user's full name, primary group, supplementary groups, and shell.# Add each of your new pod mate accounts users to the group <code>ops235</code> (in other words, add ops235 to each user as a supplementary group).
# Examine <code>/etc/group</code>. What has changed?
# Experiment with your pod-mate accounts to share and deny access to same group members by creating directories and files, and use the <code>chmod</code> command. How is the <code>/etc/group</code> related to file sharing permissions?# Use the <code>usermod</code> command to associate each of your pod mates' full name to their user name, as shown in your text. With each change, examine their entries in the <code>/etc/passwd</code> file. What has changed?# Just for interest, how would you use a graphical utility to modify user account information?
# Be sure to record your observations in your lab notes.
{{Admon/important|Shutdown VMs|It is time to safely shut-down all of your Virtual Machines. Please proceed to '''Completing the Lab'''}}
'''Answer the Investigation 9 observations / questions in your lab log book.'''
<!-- == Investigation 13: Security Tip: Removing Unnecessary Users and Groups ==
#* nscd (if not using nscd)
#* uucp -->
= Completing the lab =
Arrange proof of the following on the screen:
# Graphical or command-line view of the two new partitions in Two PVs on '''fedora1'''.# Separate <code>/etc/fstabhome</code> entry filesystem (on an LV) in '''fedora1''' VM to automatically mount .# Larger <code>/archivehome</code> on '''fedora2''' and <code>/archive2</code>'''fedora3'''.# Evidence that Unnecessary/archive unused packages have been deleted (list at least 4, and /archive2 show that they are currently mountedno longer installed).<!-- # Proof of ops235 group entry in <codeUnnecessary accounts and groups have been removed on '''fedora1'''. -->/etc/group</code> in # Account created on '''fedora1fedora3''' VMmatching your Matrix account.# Proof of pod'''nled''' installed on the host (disk pack -mate user account information in <code>/etc/passwd</code> in main system '''fedora1f13host''' VM).# Proof Answer to this question: #* What is the license of new VM backupsthe '''nautilus''' package?# Fresh backup of the virtual machines.
= Preparing for the Quizzes =
# What is the reason to extend a Volume GroupVG? PV? LV? # What does yum do that rpm does not?# What is the purpose total size of the file called <code>/etc/fstab</code>"main" VG on your system?# How do you ensure that create a file-system is mounted every time that a system is startedLV?# How do you delete an LV?# What are the purposes of How would you add the following files: disk partition <code>/etcdev/passwdsdb7</code>, <code>/etc/shadow</code>, <code>/etc/to your volume group</code>"main"?# Explain How would you increase the purpose size of the <code>/etc/skel</code> directory.root filesystem by 50 MB?# What do is the terms purpose of <code>UID</code> and <code>GID etc/fstab</code>represent. What is their purpose?# List the steps What did you have to create a user account on a system.# List the steps to change user account information on a system.# List the steps do in order for users to share file and directory accounts as "same group members".# List move the steps to remove home directories onto a user account. What is required to remove a user account's home directory as wellnew filesystem? Why?

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