[[Category:OPS235]][[Category:OPS235 Labs]]
{{Admon/importantcaution|Lab4 Being RewrittenTHIS IS AN OLD VERSION OF THE LAB|Investigations 1-4 will be changed soon'''This is an archived version. If you want to get started early on Do not use this lab - start with the user/group management investigations in your OPS235 course.'''}}= Storage Setup (5-9prior to starting Lab 4)}}=
=Working with Partitions At this point, having completed [[OPS235 Lab 3|Lab 3]] you should have <u>roughly</ User & 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 '''f17host (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 (Continued) =
{{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 [http://linuxmanpages.com/ http://linuxmanpages.com]):
{|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]>*[http://linuxmanpages.com/man8/cfdisk.8.php cfdisk]*[http://linuxmanpages.com/man8/mkfs.ext3.8.php mkfs.ext3]*[http://linuxmanpages.com/man8/mount.8.php mount]*[http://linuxmanpages.com/man8/umount.8.php umount]|* [http://linux.die.net/man/5/passwd /etc/passwd File]* [http://www.linuxhowtos.org/Tips%20and%20Tricks/using_skel.htm /etc/skel File]* [http://www.cyberciti.biz/faq/understanding-etcgroup-file/ /etc/group File]*[http://linuxmanpages.com/man8/useradd.8.php useradd]*[http://linuxmanpages.com/man8/userdel.8.php userdel]*[http://linuxmanpages.com/man8/usermod.8.php usermodLogical Volume Management]*[http://linuxmanpages.com/man8/groupadd.8.php groupadd]*[http://linuxmanpages.com/man8/groupdel.8.php groupdel]*[http://linuxmanpages.com/man1/chmod.1.php chmod]
|}
==Resources on the webInvestigation 1: 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 in '''lab3'''), 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 2:* [[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>Details.net/display# 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/www.itwire.com/content''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 3: How can I use LVM to manage storage on my disk pack? =='''Perform this investigation on fedora1 On your <u>f17host</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 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 lable '''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.
'''You need to be comfortable with these concepts on tests - make useful notes in your lab log book.'''
== Investigation 2: Create partition (command-line method) ==
'''Perform this investigation on fedora1.'''
# There are two command-line programs that can be used for working with partitions on linux: fdisk (something rather unique) and cfdisk (something like the old DOS fdisk, 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 this investigation.
# Give the full path to the hard drive device (vdb) as the first parameter to fdisk. If you don't understand what this means - you may want to do a review of some parts of ULI101.
# Create a new primary partition on the drive, using up all the available free (unpartitioned) space. Tip: in fdisk use the '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 this partition yet. We need to create a filesystem (both system-config-lvm and gparted did the following step automatically):
:* mkfs.ext4 /dev/vdb2 -L archive2
# 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.'''
== Investigation 3: Manually Mounting / Unmounting Filesystems ==
'''Perform this investigation on the VM named ''<u>fedora2</u>''.'''
So far, we have simply assumed that when the Fedora OS boots-up, that its file-system is automatically available. In this investigation, you will learn how file-systems (or portions of file-systems) can be mounted or "connected" to existing file-systems. You will also learn how to unmount (or "disconnect") portions of file-systems from existing file-systems.
# Boot-up your '''Fedora2''' VM.
# Open a terminal and login as root.
# Issue 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 both '''lv_root''' and '''lv_home'''. What commands would issue to quickly obtain this information?
# Issue the command '''umount /archive'''. Did anything happen? Issue the '''mount''' command again. Is there any difference with the command output?
# View the online man pages for the [http://linuxmanpages.com/man8/mount.8.php mount] command. Issue the <code>mount</code> command with arguments to "re-connect" the device '''/dev/mapper/vg_fedora2-lv_archive''' to the '''/archive''' directory (refer to the section '''Linux Command Online Reference''' above).
{{Admon/note|File-System Type Option No Longer Required for Mount Command|When viewing examples online, you may notice that the -t option is used with the mount command to indicate the version or type of file-system to mount.<br />'''The -t option is no longer required for the mount command''', However, it can be used to restrict the mount command so that it only mounts the filesystem ''if'' it of the type listed in the -t option.|}}
<ol>
<li value="7">Explain how the ''mount'' command would be useful for Linux system administration.</li>
<li>Unmount the '''/archive''' directory.</li>
<li>Issue a command to verify that he '''/archive''' directory has been unmounted.</li>
</ol>
'''Answer the Investigation 3 observations / questions in your lab log book.'''
== Investigation 4: How Partitions are Automatically Mounted Upon Boot-up ==
'''Perform this investigation on the VM named ''<u>fedora2</u>''.'''
#Create a directory called '''/storage''' (i.e. ''storage'' is a subdirectory of the root directory)
#Check the man page for <code>/etc/fstab</code> by entering the command <code>man fstab</code>
#Edit your <code>/etc/fstab</code> file to mount the partition <code>/dev/mapper/vg_fedora2-lv_archive</code> to <code>'''/storage'''</code>
#Issue this command:
::<code>mount -a</code>
<ol>
<li value="5">What does that command do?</li>
<li>Confirm that the partition mounted.</li>
<li>Issue a command to list the contents of '''/storage'''. Are there any files?
<li>Reboot the fedora2 VM, and verify that '''/storage''' has now been automatically mounted.</li>
<li>In the previous investigation, we mounted the directory as '''/archive''', but in this investigation we automatically mounted it as '''/storage'''. What purpose does could this server for a Linux system administrator?</li>
</ol>
'''Answer the Investigation 4 observations / questions in your lab log book.'''
= User/Group Management =
== Investigation 54: 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: http://linux.die.net/man/5/passwd
# 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 65: Adding users ==
'''{{Admon/note|Use f17host|Perform this investigation on these steps in the VM named ''<u>fedora1</u>''.f17host'''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: http://www.linuxhowtos.org/Tips%20and%20Tricks/using_skel.htm
#* 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 76: 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 87: 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> directoryfile. What do you notice?
'''Answer the Investigation 8 Be sure to record your observations / questions in your lab log booknotes.'''
== Investigation 8: Modifying users ==
== Investigation 9: 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:
# Increased volume group size for Two PVs on '''fedora1''' VM.# Correct Linux command sequence to Add a PV to an exiting VG# Separate <code>/etc/fstabhome</code> entry filesystem (on an LV) in '''fedora2fedora1''' VM to automatically mount .<code>/storage</code!-- # Unnecessary accounts and groups have been removed on '''fedora1'''. --># Proof Account created on '''fedora3''' matching your Matrix account.# List contents of ops235 group entry in <code>'''/etc/group</code> in '''fedora1file (ops235 group).# List contents of ''' VM# Proof of pod-mate user account information in <code>/etc/passwd</code> in '''fedora1''' VMfile (created accounts).# Proof Fresh backup of VM backupsthe virtual machines.
= Preparing for the Quizzes =
# What is the reason to extend a Volume GroupVG? PV? LV?# 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"?# How would you increase the size of the root filesystem by 50 MB?# Explain What is the purpose of the <code>/etc/skelfstab</code> directory.?# What do is the terms purpose of <code>UID</code> and <code>GID etc/shadow</code>represent. What is their purpose?# List the steps to create a user account on a system.# List the steps to change user account information on a system.# List the steps in order for users to share file and directory accounts as "same group members".# List the steps to remove a user account. What is required to remove a user account's home directory as well?
